From Live Science: “The Higgs boson could have kept our universe from collapsing”

From Live Science

1.24.22
Paul Sutter

Other patches in the multiverse would have, instead, met their ends.

Physicists have proposed our universe might be a tiny patch of a much larger cosmos that is constantly and rapidly inflating and popping off new universes. In our corner of this multiverse, the mass of the Higgs boson was low enough that this patch did not collapse like others may have. Image credit: MARK GARLICK/SCIENCE PHOTO LIBRARY via Getty Images.

The Higgs boson, the mysterious particle that lends other particles their mass, could have kept our universe from collapsing. And its properties might be a clue that we live in a multiverse of parallel worlds, a wild new theory suggests.

That theory, in which different regions of the universe have different sets of physical laws, would suggest that only worlds in which the Higgs boson is tiny would survive.

If true, the new model would entail the creation of new particles, which in turn would explain why the strong interaction — which ultimately keeps atoms from collapsing — seems to obey certain symmetries. And along the way, it could help reveal the nature of Dark Matter — the elusive substance that makes up most matter.

A tale of two Higgs

In 2012, the Large Hadron Collider achieved a truly monumental feat; this underground particle accelerator along the French-Swiss border detected for the first time the Higgs boson, a particle that had eluded physicists for decades.

The European Organization for Nuclear Research [Organización Europea para la Investigación Nuclear][Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) [CERN].

The European Organization for Nuclear Research [Organización Europea para la Investigación Nuclear][Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH)[CERN] map.

CERN LHC tube in the tunnel. Credit: Maximilien Brice and Julien Marius Ordan.

SixTRack CERN LHC particles.

The Higgs boson is a cornerstone of the Standard Model.

European Organization for Nuclear Research [Organización Europea para la Investigación Nuclear][Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) ATLAS Higgs Event June 18, 2012.

European Organization for Nuclear Research [Organización Europea para la Investigación Nuclear][Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) CMS Higgs Event May 27, 2012.

This particle gives other particles their mass and creates the distinction between the weak interaction and the electromagnetic interaction.

But with the good news came some bad. The Higgs had a mass of 125 gigaelectronvolts (GeV), which was orders of magnitude smaller than what physicists had thought it should be.

To be perfectly clear, the framework physicists use to describe the zoo of subatomic particles, known as the Standard Model, doesn’t actually predict the value of the Higgs mass.

Standard Model of Particle Physics, Quantum Diaries.

For that theory to work, the number has to be derived experimentally. But back-of-the-envelope calculations made physicists guess that the Higgs would have an incredibly large mass. So once the champagne was opened and the Nobel prizes were handed out, the question loomed: Why does the Higgs have such a low mass?

In another, and initially unrelated problem, the strong interaction isn’t exactly behaving as the Standard Model predicts it should. In the mathematics that physicists use to describe high-energy interactions, there are certain symmetries. For example, there is the symmetry of charge (change all the electric charges in an interaction and everything operates the same), the symmetry of time (run a reaction backward and it’s the same), and the symmetry of parity (flip an interaction around to its mirror-image and it’s the same).

In all experiments performed to date, the strong interaction appears to obey the combined symmetry of both charge reversal and parity reversal. But the mathematics of the strong interaction do not show that same symmetry. No known natural phenomena should enforce that symmetry, and yet nature seems to be obeying it.

What gives?

A matter of multiverses

A pair of theorists, Raffaele Tito D’Agnolo of the French Alternative Energies and Atomic Energy Commission (CEA) and Daniele Teresi of CERN, thought that these two problems might be related. In a paper published in January to the journal Physical Review Letters, they outlined their solution to the twin conundrums.

Their solution: The universe was just born that way.

They invoked an idea called the multiverse, which is born out of a theory called inflation. Inflation is the idea that in the earliest days of the Big Bang, our cosmos underwent a period of extremely enhanced expansion, doubling in size every billionth of a second.

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Inflation

Alan Guth, from M.I.T., who first proposed cosmic inflation.

Lamda Cold Dark Matter Accerated Expansion of The universe http scinotions.com the-cosmic-inflation-suggests-the-existence-of-parallel-universes. Credit: Alex Mittelmann.

Alan Guth’s notes:
Alan Guth’s original notes on inflation.
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Physicists aren’t exactly sure what powered inflation or how it worked, but one outgrowth of the basic idea is that our universe has never stopped inflating. Instead, what we call “our universe” is just one tiny patch of a much larger cosmos that is constantly and rapidly inflating and constantly popping off new universes, like foamy suds in your bathtub.

Different regions of this “multiverse” will have different values of the Higgs mass. The researchers found that universes with a large Higgs mass find themselves catastrophically collapsing before they get a chance to grow. Only the regions of the multiverse that have low Higgs masses survive and have stable expansion rates, leading to the development of galaxies, stars, planets and eventually high-energy particle colliders.

To make a multiverse with varying Higgs masses, the team had to introduce two more particles into the mix. These particles would be new additions to the Standard Model. The interactions of these two new particles set the mass of the Higgs in different regions of the multiverse.

And those two new particles are also capable of doing other things.

Time for a test

The newly proposed particles modify the strong interaction, leading to the charge-parity symmetry that exists in nature. They would act a lot like an axion, another hypothetical particle that has been introduced in an attempt to explain the nature of the strong interaction.

The new particles don’t have a role limited to the early universe, either. They might still be inhabiting the present-day cosmos. If one of their masses is small enough, it could have evaded detection in our accelerator experiments, but would still be floating around in space.

In other words, one of these new particles could be responsible for the Dark Matter, the invisible stuff that makes up over 85% of all the matter in the universe.

It’s a bold suggestion: solving two of the greatest challenges to particle physics and also explaining the nature of Dark Matter.

Could a solution really be this simple? As elegant as it is, the theory still needs to be tested. The model predicts a certain mass range for the Dark Matter, something that future experiments that are on the hunt for dark matter, like the underground facility the Super Cryogenic Dark Matter Search, could determine. Also, the theory predicts that the neutron should have a small but potentially measurable asymmetry in the electric charges within the neutron, a difference from the predictions of the Standard Model.

Unfortunately, we’re going to have to wait awhile. Each of these measurements will take years, if not decades, to effectively rule out — or support – the new idea.

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Dark Matter Background
Fritz Zwicky discovered Dark Matter in the 1930s when observing the movement of the Coma Cluster., Vera Rubin a Woman in STEM, denied the Nobel, some 30 years later, did most of the work on Dark Matter.

Fritz Zwicky.
Coma cluster via NASA/ESA Hubble, the original example of Dark Matter discovered during observations by Fritz Zwicky and confirmed 30 years later by Vera Rubin.
In modern times, it was astronomer Fritz Zwicky, in the 1930s, who made the first observations of what we now call dark matter. His 1933 observations of the Coma Cluster of galaxies seemed to indicated it has a mass 500 times more than that previously calculated by Edwin Hubble. Furthermore, this extra mass seemed to be completely invisible. Although Zwicky’s observations were initially met with much skepticism, they were later confirmed by other groups of astronomers.

Thirty years later, astronomer Vera Rubin provided a huge piece of evidence for the existence of dark matter. She discovered that the centers of galaxies rotate at the same speed as their extremities, whereas, of course, they should rotate faster. Think of a vinyl LP on a record deck: its center rotates faster than its edge. That’s what logic dictates we should see in galaxies too. But we do not. The only way to explain this is if the whole galaxy is only the center of some much larger structure, as if it is only the label on the LP so to speak, causing the galaxy to have a consistent rotation speed from center to edge.

Vera Rubin, following Zwicky, postulated that the missing structure in galaxies is dark matter. Her ideas were met with much resistance from the astronomical community, but her observations have been confirmed and are seen today as pivotal proof of the existence of dark matter.
Astronomer Vera Rubin at the Lowell Observatory in 1965, worked on Dark Matter (The Carnegie Institution for Science).

Vera Rubin, with Department of Terrestrial Magnetism (DTM) image tube spectrograph attached to the Kitt Peak 84-inch telescope, 1970.

Vera Rubin measuring spectra, worked on Dark Matter(Emilio Segre Visual Archives AIP SPL).
Dark Matter Research

Super Cryogenic Dark Matter Search from DOE’s SLAC National Accelerator Laboratory (US) at Stanford University (US) at SNOLAB (Vale Inco Mine, Sudbury, Canada).

LBNL LZ Dark Matter Experiment (US) xenon detector at Sanford Underground Research Facility(US) Credit: Matt Kapust.

Lamda Cold Dark Matter Accerated Expansion of The universe http scinotions.com the-cosmic-inflation-suggests-the-existence-of-parallel-universes. Credit: Alex Mittelmann.

DAMA at Gran Sasso uses sodium iodide housed in copper to hunt for dark matter LNGS-INFN.

Yale HAYSTAC axion dark matter experiment at Yale’s Wright Lab.

DEAP Dark Matter detector, The DEAP-3600, suspended in the SNOLAB (CA) deep in Sudbury’s Creighton Mine.

The LBNL LZ Dark Matter Experiment (US) Dark Matter project at SURF, Lead, SD, USA.

DAMA-LIBRA Dark Matter experiment at the Italian National Institute for Nuclear Physics’ (INFN’s) Gran Sasso National Laboratories (LNGS) located in the Abruzzo region of central Italy.

DARWIN Dark Matter experiment. A design study for a next-generation, multi-ton dark matter detector in Europe at The University of Zurich [Universität Zürich](CH).

PandaX II Dark Matter experiment at Jin-ping Underground Laboratory (CJPL) in Sichuan, China.

Inside the Axion Dark Matter eXperiment U Washington (US) Credit : Mark Stone U. of Washington. Axion Dark Matter Experiment.
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See the full article here .

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From Physics : “Multiverse Explanation for Small Higgs Mass”

About Physics

From Physics

January 12, 2022
Katherine Wright

sakkmesterke/stock.adobe.com.

A new model that assumes that a multitude of universes existed when our Universe first formed may explain why the Higgs mass is smaller than traditional models predict.

The standard model of particle physics has been inordinately successful, providing experimental predictions that accurately describe most of our Universe’s forces and fundamental particles.

Standard Model of Particle Physics, Quantum Diaries.

But the model has some glaring holes. It contains no viable Dark Matter particle, it lacks an explanation for the Universe’s accelerating expansion, and it predicts a Higgs boson mass that is at least triple that measured in experiments.

European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) ATLAS Higgs Event June 18, 2012.

European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) CMS Higgs Event May 27, 2012.

Now, Raffaele Tito D’Agnolo of The University of Paris-Saclay (FR) and Daniele Teresi of The European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire](CH) have developed a model that provides an explanation for the lightness of the Higgs.

Science paper:
Physical Review Letters

The duo says that their model, which invokes multiverses, could also explain other conundrums, such as the observed similarity in how matter and antimatter experience strong interactions.

As a starting point for their model, the researchers assume that at very early times in our Universe’s history there existed a multitude of universes. Each universe contained Higgs bosons with inhomogeneous masses: some regions of each universe contained a heavy Higgs boson, while others contained a very light version.

By watching how this so-called multiverse evolved over time, the researchers found that regions having a large Higgs were unstable and collapsed in times as short as 10^−5s. That collapse, also known as crunching, destroyed those multiverse components. The only remaining universe—ours—contained a very light Higgs boson. D’Agnolo and Teresi also found another factor in their model that prevented this universe from being crunched: a symmetric strong interaction—a fundamental force of nature that occurs between subatomic particles—for matter and antimatter. This symmetry is another hole of the standard model. The team says that their model should be testable in future dark matter and hadronic experiments.

See the full article here .

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Physicists are drowning in a flood of research papers in their own fields and coping with an even larger deluge in other areas of physics. How can an active researcher stay informed about the most important developments in physics? Physics highlights a selection of papers from the Physical Review journals. In consultation with expert scientists, the editors choose these papers for their importance and/or intrinsic interest. To highlight these papers, Physics features three kinds of articles: Viewpoints are commentaries written by active researchers, who are asked to explain the results to physicists in other subfields. Focus stories are written by professional science writers in a journalistic style and are intended to be accessible to students and non-experts. Synopses are brief editor-written summaries. Physics provides a much-needed guide to the best in physics, and we welcome your comments.

From Wright Laboratory at Yale University (US) : “ALICE first collision data demonstrates success of Wright Lab detector upgrade”

From Wright Laboratory

At

Yale University (US)

November 12, 2021 {Just today in social media.]

Wright Lab’s Relativistic Heavy Ion Group (RHIG), led by professor of physics Helen Caines and D. Allan Bromley Professor Emeritus of Physics John Harris, has been taking advantage of the extended 3-year shutdown of the Large Hadron Collider (LHC)–the world’s largest and most powerful particle accelerator located at the Center for European Nuclear Research (CERN) in Geneva, Switzerland–to contribute to the upgrade of one of the LHC’s detectors, called A Large Ion Collider Experiment (ALICE).

Image courtesy of Yale RHIG/ALICE Collaboration.

Iconic view of the European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) [CERN] ALICE Detector.

European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) [CERN].

European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire (CH) map.

CERN LHC tunnel and tube.

SixTRack CERN LHC particles.

ALICE uses collisions of heavy nuclei, as well as proton-proton and proton-nucleus collisions, to study the physics of strongly interacting matter at the highest energy densities reached so far in the laboratory. The primary goal of the experiment is to re-create the quark-gluon plasma (QGP) state of matter, which is predicted by the Standard Model of particle physics to have existed ten millionths of a second after the Big Bang.

After several years of construction and then installation during the LHC shutdown, the upgraded LHC started delivering stable beams in collision for detectors on October 27, 2021. ALICE immediately started taking data to test its new detector systems—including a completely new silicon inner tracking system (10 m2 of active silicon area and nearly 13 billion pixels) and new Time Projection Chamber (TPC) endcap readout–as well as its online and offline software.

Wright Lab research scientist Nikolai Smirnov and the late Richard Majka, also a research scientist in Wright Lab’s RHIG, were in charge of the assembly and testing of ALICE’s inner Gas Electron Multiplier (GEM) TPC chambers in Wright Lab. Majka also served as the U.S. Project Leader for the U.S. Department of Energy (DOE) supported GEM-TPC construction project effort. Graduate students from RHIG also played an important role in the R&D for this new type of TPC readout prior to its construction.

The GEM-TPC (cylindrical tracking detector 5 meters in diameter, 5 meters long) and its new readout electronics feature a continuous readout mode that allows ALICE to record the thousands of tracks produced in Pb-Pb collisions at event rates of 50 kHz leading to a staggering data rate of 3.5 TB/s.

Seen in the online display (see snapshot pictured, above) is the real-time sequence of the continuous TPC data stream in 11 millisecond slices. Tracks from individual proton-proton collision events can be seen as they curve through the magnetic field along the cylindrical axis. Given the continuously streaming, real-time data readout and the new detector systems, ALICE expects to accumulate 50 times more heavy-ion collision data in the upcoming LHC Run 3 than in Runs 1 and 2 combined.

In addition to leading construction of the inner sectors of the ALICE TPC upgrade, RHIG at Yale has been engaged with the ALICE Collaboration since its beginning. The Wright Lab group has contributed significantly to ALICE analyses and papers, as well as the original design of the detector. The Wright Lab group assembled, tested, calibrated, and installed the electromagnetic calorimeter (EMCal) in ALICE. Harris is a past chair of the ALICE Collaboration Board. Furthermore, the group engages in simulations, R&D, design and prototyping of future detectors.

See the full article here .

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Wright Lab is advancing the frontiers of fundamental physics through a broad research program in nuclear, particle, and astrophysics that includes precision studies of neutrinos; searches for dark matter; investigations of the building blocks and interactions of matter; exploration of quantum science and its applications for fundamental physics experiments; and observations of the early Universe. The laboratory’s unique combination of on-site state-of-the-art research facilities, technical infrastructure, and interaction spaces supports innovative instrumentation development, hands-on research, and training the next generation of scientists. Wright Lab is a part of the Yale Department of Physics and houses several Yale University core facilities that serve researchers across Yale’s Science Hill and beyond.

Mission

The mission of Yale Wright Laboratory is to advance understanding of the physical world, from the smallest particles to the evolution of the Universe, by engaging in fundamental research, developing novel applications, training future leaders in research and development, educating scholars, and enabling discovery.

Wright Lab supports a diverse community of scientists, staff, and students who advance our mission and fosters cross-disciplinary collaborations across Yale University and worldwide.

Climate Statement

The Yale Wright Laboratory is committed to diversity, equity, and inclusion among all students, staff, and faculty. The goal of our lab community is to provide a safe and supportive environment for research, teaching, and mentoring. Diversity, equity, and inclusion are core principles of our work place and part of the excellence we aim for.

Resources

Wright Lab, the Yale Department of Physics, and Yale University offer a number of resources on topics of climate, diversity, equity, and inclusion. In addition, the Committee on Climate and Diversity in the Physics Department is a point of contact for all questions and concerns. Please visit the following links for more information and a list of resources.

Collaboration

With its on-site core facilities and research program, Wright Lab fosters cross-disciplinary research collaborations across Yale University and worldwide. Wright Lab works with the Yale Center for Research Computing (YCRC) on novel solutions to the research computing challenges in nuclear, particle and astrophysics, and collaborates with the Yale Center for Astronomy and Astrophysics (YCAA) on understanding dark matter in the Universe. Quantum sensors and techniques jointly developed with the Yale Quantum Institute (YQI) are used for axion searches at Wright Lab.

Wright Lab also has strong, interdisciplinary partnerships with the Yale Center for Collaborative Arts and Media, the Yale Peabody Museum of Natural History, and Yale Pathways to Science.

Funding

Wright Laboratory gratefully acknowledges support from the Alfred P. Sloan Foundation; the Department of Energy, Office of Science, High Energy Physics and Nuclear Physics; the Heising-Simons Foundation; the Krell Institute; the National Science Foundation; and Yale University.

Yale University (US) is a private Ivy League research university in New Haven, Connecticut. Founded in 1701 as the Collegiate School, it is the third-oldest institution of higher education in the United States and one of the nine Colonial Colleges chartered before the American Revolution. The Collegiate School was renamed Yale College in 1718 to honor the school’s largest private benefactor for the first century of its existence, Elihu Yale. Yale University is consistently ranked as one of the top universities and is considered one of the most prestigious in the nation.

Chartered by Connecticut Colony, the Collegiate School was established in 1701 by clergy to educate Congregational ministers before moving to New Haven in 1716. Originally restricted to theology and sacred languages, the curriculum began to incorporate humanities and sciences by the time of the American Revolution. In the 19th century, the college expanded into graduate and professional instruction, awarding the first PhD in the United States in 1861 and organizing as a university in 1887. Yale’s faculty and student populations grew after 1890 with rapid expansion of the physical campus and scientific research.

Yale is organized into fourteen constituent schools: the original undergraduate college, the Yale Graduate School of Arts and Sciences and twelve professional schools. While the university is governed by the Yale Corporation, each school’s faculty oversees its curriculum and degree programs. In addition to a central campus in downtown New Haven, the university owns athletic facilities in western New Haven, a campus in West Haven, Connecticut, and forests and nature preserves throughout New England. As of June 2020, the university’s endowment was valued at $31.1 billion, the second largest of any educational institution. The Yale University Library, serving all constituent schools, holds more than 15 million volumes and is the third-largest academic library in the United States. Students compete in intercollegiate sports as the Yale Bulldogs in the NCAA Division I – Ivy League.

As of October 2020, 65 Nobel laureates, five Fields Medalists, four Abel Prize laureates, and three Turing award winners have been affiliated with Yale University. In addition, Yale has graduated many notable alumni, including five U.S. Presidents, 19 U.S. Supreme Court Justices, 31 living billionaires, and many heads of state. Hundreds of members of Congress and many U.S. diplomats, 78 MacArthur Fellows, 252 Rhodes Scholars, 123 Marshall Scholars, and nine Mitchell Scholars have been affiliated with the university.

Research

Yale is a member of the Association of American Universities (AAU) (US) and is classified among “R1: Doctoral Universities – Very high research activity”. According to the National Science Foundation (US), Yale spent $990 million on research and development in 2018, ranking it 15th in the nation.

Yale’s faculty include 61 members of the National Academy of Sciences (US), 7 members of the National Academy of Engineering (US) and 49 members of the American Academy of Arts and Sciences (US). The college is, after normalization for institution size, the tenth-largest baccalaureate source of doctoral degree recipients in the United States, and the largest such source within the Ivy League.

Yale’s English and Comparative Literature departments were part of the New Criticism movement. Of the New Critics, Robert Penn Warren, W.K. Wimsatt, and Cleanth Brooks were all Yale faculty. Later, the Yale Comparative literature department became a center of American deconstruction. Jacques Derrida, the father of deconstruction, taught at the Department of Comparative Literature from the late seventies to mid-1980s. Several other Yale faculty members were also associated with deconstruction, forming the so-called “Yale School”. These included Paul de Man who taught in the Departments of Comparative Literature and French, J. Hillis Miller, Geoffrey Hartman (both taught in the Departments of English and Comparative Literature), and Harold Bloom (English), whose theoretical position was always somewhat specific, and who ultimately took a very different path from the rest of this group. Yale’s history department has also originated important intellectual trends. Historians C. Vann Woodward and David Brion Davis are credited with beginning in the 1960s and 1970s an important stream of southern historians; likewise, David Montgomery, a labor historian, advised many of the current generation of labor historians in the country. Yale’s Music School and Department fostered the growth of Music Theory in the latter half of the 20th century. The Journal of Music Theory was founded there in 1957; Allen Forte and David Lewin were influential teachers and scholars.

In addition to eminent faculty members, Yale research relies heavily on the presence of roughly 1200 Postdocs from various national and international origin working in the multiple laboratories in the sciences, social sciences, humanities, and professional schools of the university. The university progressively recognized this working force with the recent creation of the Office for Postdoctoral Affairs and the Yale Postdoctoral Association.

Notable alumni

Over its history, Yale has produced many distinguished alumni in a variety of fields, ranging from the public to private sector. According to 2020 data, around 71% of undergraduates join the workforce, while the next largest majority of 16.6% go on to attend graduate or professional schools. Yale graduates have been recipients of 252 Rhodes Scholarships, 123 Marshall Scholarships, 67 Truman Scholarships, 21 Churchill Scholarships, and 9 Mitchell Scholarships. The university is also the second largest producer of Fulbright Scholars, with a total of 1,199 in its history and has produced 89 MacArthur Fellows. The U.S. Department of State Bureau of Educational and Cultural Affairs ranked Yale fifth among research institutions producing the most 2020–2021 Fulbright Scholars. Additionally, 31 living billionaires are Yale alumni.

At Yale, one of the most popular undergraduate majors among Juniors and Seniors is political science, with many students going on to serve careers in government and politics. Former presidents who attended Yale for undergrad include William Howard Taft, George H. W. Bush, and George W. Bush while former presidents Gerald Ford and Bill Clinton attended Yale Law School. Former vice-president and influential antebellum era politician John C. Calhoun also graduated from Yale. Former world leaders include Italian prime minister Mario Monti, Turkish prime minister Tansu Çiller, Mexican president Ernesto Zedillo, German president Karl Carstens, Philippine president José Paciano Laurel, Latvian president Valdis Zatlers, Taiwanese premier Jiang Yi-huah, and Malawian president Peter Mutharika, among others. Prominent royals who graduated are Crown Princess Victoria of Sweden, and Olympia Bonaparte, Princess Napoléon.

Yale alumni have had considerable presence in U.S. government in all three branches. On the U.S. Supreme Court, 19 justices have been Yale alumni, including current Associate Justices Sonia Sotomayor, Samuel Alito, Clarence Thomas, and Brett Kavanaugh. Numerous Yale alumni have been U.S. Senators, including current Senators Michael Bennet, Richard Blumenthal, Cory Booker, Sherrod Brown, Chris Coons, Amy Klobuchar, Ben Sasse, and Sheldon Whitehouse. Current and former cabinet members include Secretaries of State John Kerry, Hillary Clinton, Cyrus Vance, and Dean Acheson; U.S. Secretaries of the Treasury Oliver Wolcott, Robert Rubin, Nicholas F. Brady, Steven Mnuchin, and Janet Yellen; U.S. Attorneys General Nicholas Katzenbach, John Ashcroft, and Edward H. Levi; and many others. Peace Corps founder and American diplomat Sargent Shriver and public official and urban planner Robert Moses are Yale alumni.

Yale has produced numerous award-winning authors and influential writers, like Nobel Prize in Literature laureate Sinclair Lewis and Pulitzer Prize winners Stephen Vincent Benét, Thornton Wilder, Doug Wright, and David McCullough. Academy Award winning actors, actresses, and directors include Jodie Foster, Paul Newman, Meryl Streep, Elia Kazan, George Roy Hill, Lupita Nyong’o, Oliver Stone, and Frances McDormand. Alumni from Yale have also made notable contributions to both music and the arts. Leading American composer from the 20th century Charles Ives, Broadway composer Cole Porter, Grammy award winner David Lang, and award-winning jazz pianist and composer Vijay Iyer all hail from Yale. Hugo Boss Prize winner Matthew Barney, famed American sculptor Richard Serra, President Barack Obama presidential portrait painter Kehinde Wiley, MacArthur Fellow and contemporary artist Sarah Sze, Pulitzer Prize winning cartoonist Garry Trudeau, and National Medal of Arts photorealist painter Chuck Close all graduated from Yale. Additional alumni include architect and Presidential Medal of Freedom winner Maya Lin, Pritzker Prize winner Norman Foster, and Gateway Arch designer Eero Saarinen. Journalists and pundits include Dick Cavett, Chris Cuomo, Anderson Cooper, William F. Buckley, Jr., and Fareed Zakaria.

In business, Yale has had numerous alumni and former students go on to become founders of influential business, like William Boeing (Boeing, United Airlines), Briton Hadden and Henry Luce (Time Magazine), Stephen A. Schwarzman (Blackstone Group), Frederick W. Smith (FedEx), Juan Trippe (Pan Am), Harold Stanley (Morgan Stanley), Bing Gordon (Electronic Arts), and Ben Silbermann (Pinterest). Other business people from Yale include former chairman and CEO of Sears Holdings Edward Lampert, former Time Warner president Jeffrey Bewkes, former PepsiCo chairperson and CEO Indra Nooyi, sports agent Donald Dell, and investor/philanthropist Sir John Templeton,

Yale alumni distinguished in academia include literary critic and historian Henry Louis Gates, economists Irving Fischer, Mahbub ul Haq, and Nobel Prize laureate Paul Krugman; Nobel Prize in Physics laureates Ernest Lawrence and Murray Gell-Mann; Fields Medalist John G. Thompson; Human Genome Project leader and National Institutes of Health (US) director Francis S. Collins; brain surgery pioneer Harvey Cushing; pioneering computer scientist Grace Hopper; influential mathematician and chemist Josiah Willard Gibbs; National Women’s Hall of Fame inductee and biochemist Florence B. Seibert; Turing Award recipient Ron Rivest; inventors Samuel F.B. Morse and Eli Whitney; Nobel Prize in Chemistry laureate John B. Goodenough; lexicographer Noah Webster; and theologians Jonathan Edwards and Reinhold Niebuhr.

In the sporting arena, Yale alumni include baseball players Ron Darling and Craig Breslow and baseball executives Theo Epstein and George Weiss; football players Calvin Hill, Gary Fenick, Amos Alonzo Stagg, and “the Father of American Football” Walter Camp; ice hockey players Chris Higgins and Olympian Helen Resor; Olympic figure skaters Sarah Hughes and Nathan Chen; nine-time U.S. Squash men’s champion Julian Illingworth; Olympic swimmer Don Schollander; Olympic rowers Josh West and Rusty Wailes; Olympic sailor Stuart McNay; Olympic runner Frank Shorter; and others.

From The Conversation (AU) via phys.org : “2021 A year physicists asked ‘What lies beyond the Standard Model?'”

From The Conversation (AU)

via

phys.org

December 23, 2021
Aaron McGowan, The Conversation

Experiments at the Large Hadron Collider in Europe, like the ATLAS calorimeter seen here, are providing more accurate measurements of fundamental particles. Credit: Maximilien Brice, CC BY-NC.

European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) [CERN].

“If you ask a physicist like me to explain how the world works, my lazy answer might be: ‘It follows the Standard Model.’

Standard Model of Particle Physics, Quantum Diaries

The Standard Model explains the fundamental physics of how the universe works. It has endured over 50 trips around the Sun despite experimental physicists constantly probing for cracks in the model’s foundations.

With few exceptions, it has stood up to this scrutiny, passing experimental test after experimental test with flying colors. But this wildly successful model has conceptual gaps that suggest there is a bit more to be learned about how the universe works.

I am a neutrino physicist. Neutrinos represent three of the 17 fundamental particles in the Standard Model. They zip through every person on Earth at all times of day. I study the properties of interactions between neutrinos and normal matter particles.

In 2021, physicists around the world ran a number of experiments that probed the Standard Model. Teams measured basic parameters of the model more precisely than ever before. Others investigated the fringes of knowledge where the best experimental measurements don’t quite match the predictions made by the Standard Model. And finally, groups built more powerful technologies designed to push the model to its limits and potentially discover new particles and fields. If these efforts pan out, they could lead to a more complete theory of the universe in the future.

Filling holes in Standard Model

In 1897, J.J. Thomson discovered the first fundamental particle, the electron, using nothing more than glass vacuum tubes and wires. More than 100 years later, physicists are still discovering new pieces of the Standard Model.

The Standard Model of physics allows scientists to make incredibly accurate predictions about how the world works, but it doesn’t explain everything. Credit: CERN, CC BY-NC.

The Standard Model is a predictive framework that does two things. First, it explains what the basic particles of matter are. These are things like electrons and the quarks that make up protons and neutrons. Second, it predicts how these matter particles interact with each other using “messenger particles.” These are called bosons—they include photons and the famous Higgs boson—and they communicate the basic forces of nature. The Higgs boson wasn’t discovered until 2012 after decades of work at The European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire](CH), the huge particle collider in Europe.

European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) CMS Higgs Event May 27, 2012.

European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) ATLAS Higgs Event June 18, 2012.

Peter Higgs – University of Edinburgh [Oilthigh Dhùn Èideann] (SCT).

The Standard Model is incredibly good at predicting many aspects of how the world works, but it does have some holes.

Notably, it does not include any description of gravity. While Albert Einstein’s Theory of General Relativity describes how gravity works, physicists have not yet discovered a particle that conveys the force of gravity [Quantum Mechanics’ ‘graviton’]. A proper “Theory of Everything” would do everything the Standard Model can, but also include the messenger particles that communicate how gravity interacts with other particles.

Another thing the Standard Model can’t do is explain why any particle has a certain mass—physicists must measure the mass of particles directly using experiments. Only after experiments give physicists these exact masses can they be used for predictions. The better the measurements, the better the predictions that can be made.

Recently, physicists on a team at CERN measured how strongly the Higgs boson feels itself.

Twice the Higgs, twice the challenge
ATLAS searches for pairs of Higgs bosons in the rare bbɣɣ decay channel, 29 March 2021.

Another CERN team also measured the Higgs boson’s mass more precisely than ever before.

A new result by the CMS Collaboration narrows down the mass of the Higgs boson to a precision of 0.1%.

And finally, there was also progress on measuring the mass of neutrinos.

KATRIN experiment aims to measure the mass of the neutrino using a huge device called a spectrometer (interior shown)KIT Karlsruhe Institute of Technology [Karlsruher Institut für Technologie] (DE).

Physicists know neutrinos have more than zero mass but less than the amount currently detectable. A team in Germany has continued to refine the techniques that could allow them to directly measure the mass of neutrinos.

Hints of new forces or particles

In April 2021, members of the Muon g-2 experiment at Fermilab announced their first measurement of the magnetic moment of the muon.

DOE’s Fermi National Accelerator Laboratory(US) Muon g-2 studio. As muons race around a ring at the Muon g-2 studio, their spin axes twirl, reflecting the influence of unseen particles.

The muon is one of the fundamental particles in the Standard Model, and this measurement of one of its properties is the most accurate to date. The reason this experiment was important was because the measurement didn’t perfectly match the Standard Model prediction of the magnetic moment. Basically, muons don’t behave as they should. This finding could point to undiscovered particles that interact with muons.

But simultaneously, in April 2021, physicist Zoltan Fodor and his colleagues showed how they used a mathematical method called Lattice QCD to precisely calculate the muon’s magnetic moment. Their theoretical prediction is different from old predictions, still works within the Standard Model and, importantly, matches experimental measurements of the muon.

The disagreement between the previously accepted predictions, this new result and the new prediction must be reconciled before physicists will know if the experimental result is truly beyond the Standard Model.

Upgrading the tools of physics

Physicists must swing between crafting the mind-bending ideas about reality that make up theories and advancing technologies to the point where new experiments can test those theories. 2021 was a big year for advancing the experimental tools of physics.

First, the world’s largest particle accelerator, the Large Hadron Collider at CERN, was shut down and underwent some substantial upgrades. Physicists just restarted the facility in October, and they plan to begin the next data collection run in May 2022. The upgrades have boosted the power of the collider so that it can produce collisions at 14 TeV, up from the previous limit of 13 TeV. This means the batches of tiny protons that travel in beams around the circular accelerator together carry the same amount of energy as an 800,000-pound (360,000-kilogram) passenger train traveling at 100 mph (160 kph). At these incredible energies, physicists may discover new particles that were too heavy to see at lower energies.

SixTRack CERN LHC particles.

Some other technological advancements were made to help the search for dark matter. Many astrophysicists believe that dark matter particles, which don’t currently fit into the Standard Model, could answer some outstanding questions regarding the way gravity bends around stars—called gravitational lensing—as well as the speed at which stars rotate in spiral galaxies. Projects like the Cryogenic Dark Matter Search have yet to find dark matter particles, but the teams are developing larger and more sensitive detectors to be deployed in the near future.

Gravitational Lensing National Aeronautics Space Agency (US) and European Space Agency [Agence spatiale européenne][Europäische Weltraumorganisation](EU).

Super Cryogenic Dark Matter Search at DOE’s SLAC National Accelerator Laboratory (US) at Stanford University (US) at SNOLAB (Vale Inco Mine, Sudbury, Canada).

Particularly relevant to my work with neutrinos is the development of immense new detectors like Hyper-Kamiokande and DUNE.

Hyper-Kamiokande [(神岡宇宙素粒子研究施設](JP) a neutrino physics laboratory to be located underground in the Mozumi Mine of the Kamioka Mining and Smelting Co. near the Kamioka section of the city of Hida in Gifu Prefecture, Japan.

DOE’s Fermi National Accelerator Laboratory(US) DUNE LBNF (US) from FNAL to Sanford Underground Research Facility, Lead, South Dakota, USA.

DOE’s Fermi National Accelerator Laboratory(US) DUNE LBNF (US) Caverns at Sanford Underground Research Facility.

Using these detectors, scientists will hopefully be able to answer questions about a fundamental asymmetry in how neutrinos oscillate. They will also be used to watch for proton decay, a proposed phenomenon that certain theories predict should occur.

2021 highlighted some of the ways the Standard Model fails to explain every mystery of the universe. But new measurements and new technology are helping physicists move forward in the search for the Theory of Everything.”

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From Symmetry: “Blink and it’s gone”

From Symmetry

07/13/21 [Found in a year-end round up]
Eoin O’Carroll

Fast electronics and artificial intelligence are helping physicists capture data and decide what to keep and what to throw away.

Illustration by Sandbox Studio, Chicago with Ana Kova.

The nucleus of the atom was discovered a century ago thanks to scientists who didn’t blink.

Working in pitch darkness at The University of Manchester (UK) between 1909 and 1913, research assistants Hans Geiger and Ernest Marsden peered through microscopes to count flashes of alpha particles on a fluorescent screen. The task demanded total concentration, and the scientists could count accurately for only about a minute before fatigue set in. The physicist and science historian Siegmund Brandt wrote that Geiger and Marsden maintained their focus by ingesting strong coffee and “a pinch of strychnine.”

Modern particle detectors use sensitive electronics instead of microscopes and rat poison to observe particle collisions, but now there’s a new challenge. Instead of worrying about blinking and missing interesting particle interactions, physicists worry about accidentally throwing them away.

The Large Hadron Collider at CERN produces collisions at a rate of 40 million per second, producing enough data to fill more than 140,000 one-terabyte storage drives every hour.

European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) [CERN].

European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire (CH) map.

CERN LHC tunnel and tube.

SixTRack CERN LHC particles.

Capturing all those events is impossible, so the electronics have to make some tough choices.

To decide which collisions to retain for analysis and which ones to discard, physicists use specialized systems called trigger systems. The trigger is the only component to observe every collision. In about half the time it takes a human to blink, the CMS experiment’s triggers have processed and discarded 99.9975% of the data.

European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire(CH) CMS
European Organization for Nuclear Research (Organisation européenne pour la recherche nucléaire)(EU) CMS Detector

Iconic view of the European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) [CERN] ATLAS detector.

Depending on how a trigger is programmed, it could be the first to capture evidence of new phenomena—or to lose it.

“Once we lose the data, we lose it forever,” says Georgia Karagiorgi, a professor of physics at Columbia University (US) and the US project manager for the data acquisition system for the Deep Underground Neutrino Experiment. “We need to be constantly looking. We can’t close our eyes.”

The challenge of deciding in a split second which data to keep, some scientists say, could be met with artificial intelligence.

A numbers game

Discovering new subatomic phenomena often requires amassing a colossal dataset, most of it uninteresting.

Geiger and Marsden learned this the hard way. Working under the direction of Ernest Rutherford, the two scientists sought to reveal the structures of atoms by sending streams of alpha particles through sheets of gold foil and observing how the particles scattered. They found that for about every 8000 particles that passed straight through the foil, one particle would bounce away as though it had collided with something solid. That was the atom’s nucleus, and its discovery sent physics itself on a new trajectory.

By today’s physics’ standards, Geiger and Marsden’s 1-in-8000 odds look like a safe bet. The Higgs boson is thought to appear in only one out of every 5 billion collisions in the LHC.

European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) CMS Higgs Event May 27, 2012.

European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) ATLAS Higgs Event

The triggers will soon need to get even faster. In the LHC’s Run 3, set to begin in March 2022, the total number of collisions will equal that of the two previous runs combined. The collision rate will increase dramatically during the LHC’s High-Luminosity era, which is scheduled to begin in 2027 and continue through the 2030s. That’s when the collider’s luminosity, a measure of how tightly the crossing beams are packed with particles, is set to increase tenfold over its original design value.

Collecting this data is important because in the coming decade, scientists will intensify their searches for phenomena that are just as mysterious to today’s physicists as atomic nuclei were to Geiger and Marsden.

And scientists have only a small window of time in which to catch them.

“At CMS we have a massive amount of data,” says Princeton University (US) physicist Isobel Ojalvo, who has been heavily involved in upgrading the CMS trigger system. “We’re only able to store that data for about three and a half [millionths of a second] before we make decisions about keeping it or throwing it away.”

A new physics

In 2012, the Higgs boson became the last confirmed elementary particle of the Standard Model, the equation that succinctly describes all known forms of matter and predicts with astonishing accuracy how they interact.

Standard Model of Particle Physics, Quantum Diaries

But there are strong signs that the Standard Model, which has guided physics for nearly 50 years, won’t have the last word. In April, for instance, preliminary results from the Muon g-2 experiment at The DOE’s Fermi National Accelerator Laboratory (US) offered tantalizing hints that the muon may be interacting with a force or particle the Standard Model doesn’t include.

DOE’s Fermi National Accelerator Laboratory(US) Muon g-2 studio. As muons race around a ring at the Muon g-2 studio, their spin axes twirl, reflecting the influence of unseen particles.

Identifying these phenomena and many others may require a new understanding.

“Given that we have not seen [beyond the Standard Model] physics yet, we need to revolutionize how we collect our data to enable processing data rates at least an order of magnitude higher than achieved thus far,” says The Massachusetts Institute of Technology (US) physicist Mike Williams, who is a member of the Institute for Research and Innovation in Software for High-Energy Physics, IRIS-HEP, funded by the National Science Foundation.

Physicists agree that future triggers will need to be faster, but there’s less consensus on how they should be programmed.

“How do we make discoveries when we don’t know what to look for?” asks Peter Elmer, executive director and principal investigator for IRIS-HEP. “We don’t want to throw anything away that might hint at new physics.”

There are two different schools of thought, Ojalvo says.

The more conservative approach is to search for signatures that match theoretical predictions. “Another way,” she says, “is to look for things that are different from everything else.”

This second option, known as anomaly detection, would scan not for specific signatures, but for anything that deviates from the Standard Model, something that artificial intelligence could help with.

“In the past, we guessed the model and used the trigger system to pick those signatures up,” Ojalvo says.

But “now we’re not finding the new physics that we believe is out there,” Ojalvo says. “It may be that we cannot create those interactions in present-day colliders, but we also need to ask ourselves if we’ve turned over every stone.”

Instead of searching one-by-one for signals predicted by each theory, physicists could deploy to a collider’s trigger system an unsupervised machine-learning algorithm, Ojalvo says. They could train the algorithm only on the collisions it observes, without reference to any other dataset. Over time, the algorithm would learn to distinguish common collision events from rare ones. The approach would not require knowing any details in advance about what new signals might be, and it would avoid bias toward one theory or another.

MIT physicist Philip Harris says that recent advances in artificial intelligence are fueling a growing interest in this approach—but that advocates of “theoryless searches” remain a minority in the physics community.

More generally, says Harris, using AI for triggers can create opportunities for more innovative ways to acquire data. “The algorithm will be able to recognize the beam conditions and adapt their choices,” he says. “Effectively, it can change itself.”

Programming triggers calls for tradeoffs between efficiency, breadth, accuracy and feasibility. “All of this is wonderful in theory,” says Karagiorgi. “It’s all about hardware resource constraints, power resource constraints, and, of course, cost.”

“Thankfully,” she adds, “we don’t need strychnine.”
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Symmetry is a joint Fermilab/SLAC publication.

The University of Nebraska-Lincoln (US) : “Husker team takes leading role at CERN’s Large Hadron Collider”

The University of Nebraska-Lincoln (US)

12.6.21
Ken Bloom,
Professor of Physics
402-472-6093
kenbloom@unl.edu

The University of Nebraska–Lincoln has received a five-year, $51 million grant from The National Science Foundation (US) that will advance cutting-edge work in subatomic physics at CERN’s Large Hadron Collider, the world’s largest, most powerful particle accelerator located near Geneva, Switzerland.

European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) [CERN].

European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire (CH) map.

The grant — one of the largest in the university’s history — will enable 1,200 U.S. physicists from 51 institutions to maximize the potential of the Compact Muon Solenoid [CMS] detector, an instrument at the collider used to study what happens when high-energy particles collide.

European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire(CH) CMS
European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) (EU) [CERN] CMS Detector

The funding will support the U.S. CMS Operations Program, the NSF-funded portion of which Nebraska will now lead through 2026. The program, also funded by The Department of Energy (US), maintains the operation of the U.S.-supplied-and-developed components of the CMS detector, oversees its software and computing infrastructure, and plans for future upgrades.

The operations program is foundational to maintaining and upgrading the CMS detector. The instrument functions as a giant high-speed camera within the LHC, capturing “photographs” of particle collisions that help scientists unlock mysteries about the universe’s origins and composition and glean insight into the laws of nature. The detector was integral to the 2012 discovery of the long-sought-after Higgs boson particle and is expected to spur further discoveries in particle physics.

As a leader of the operations program, Nebraska is charged with distributing funds to 19 partnering institutions, all of which are leaders in the field of particle physics. They include The Massachusetts Institute of Technology (US), The California Institute of Technology (US), Princeton University (US) and Cornell University (US).

Maintaining the CMS detector — which is 14,000 tons and has two endcaps each the size of a five-story building — is a significant undertaking and is the backbone to the research conducted at CERN.

“No one can do the research unless we do the operations and maintenance,” said Ken Bloom, professor of physics and the project’s principal investigator. “It enables research on this campus and at the 50 other CMS universities in the U.S. The whole international collaboration needs these activities in the U.S. to be successful.”

[CMS operations in the U.S.A. are based at DOE’s Fermi National Accelerator Laboratory (US) where there are 1000 people working on this project.]

Bloom’s deep experience in CMS operations and management was pivotal in bringing the NSF funding to Nebraska. For nearly a decade, he led the team that runs the seven U.S. Tier-2 computing centers for the CMS detector, one of which is housed at the university’s Holland Computing Center. Collectively, these sites process, store, transfer and analyze the millions of gigabytes of data produced by the CMS each year.

He was also manager of software and computing for the operations program from 2015 to 2019, managing a $16 million annual budget. In January, he was selected as the program’s deputy manager, helping to administer a $35 million budget that funds at least 45 institutions. That appointment triggered the shift in NSF funding to Nebraska from Princeton University, where it’s been housed for the past decade.

“This grant is a capstone to Ken’s long-term dedication to leading CMS operations on the national and global scale,” said Bob Wilhelm, vice chancellor for research and economic development. “His commitment to maximizing the instrument’s potential and strengthening its computing infrastructure, and the role our university will play in managing CMS operations, paves the way for scientists at Nebraska and around the world to continue making groundbreaking discoveries in physics.”

The university takes over at a critical point in time for the Large Hadron Collider. The instrument is poised to begin its third data-taking run in 2022, which is expected to double the size of the current CMS data set of proton collisions. In addition, a major upgrade to the accelerator is in progress, which will increase its luminosity by a factor of 10. The improved collider, to be called the High-Luminosity LHC, is expected to be in place for the fourth run’s launch in 2027 and will significantly boost the number of collisions that physicists can study.

With the expected data boom stemming from these two events, Bloom said it’s critical to devote a lion’s share of the NSF funds to enhancing the computing operations that support data analysis. The majority of the funds that stay on Nebraska’s campus will support improved software and computing power and personnel at the Holland Center.

The updated instruments at CERN will power additional research focused on the Higgs boson, the elementary particle that is believed to give other particles their mass.

European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) CMS Higgs Event May 27, 2012.

After finally discovering the so-called “God particle” in 2012 after a more than 50-year hunt, physicists are now confirming its role in the Standard Model of particle physics and using it to search for other types of hidden particles.

Standard Model of Particle Physics, Quantum Diaries

The upgraded LHC will double the supply of Higgs bosons available for study and provide higher-precision measurements of the particle.

The collider also paves the way for further exploration of Dark Matter, an invisible substance believed to compose about 25% of the universe. Scientists know it exists based on gravitational pulls exhibited by distant stars and galaxies, but they don’t know what types of particles compose it.

__________________________________________________________________________________
Dark Matter Background
Fritz Zwicky discovered Dark Matter in the 1930s when observing the movement of the Coma Cluster., Vera Rubin a Woman in STEM, denied the Nobel, some 30 years later, did most of the work on Dark Matter.

Fritz Zwicky.
Coma cluster via NASA/ESA Hubble, the original example of Dark Matter discovered during observations by Fritz Zwicky and confirmed 30 years later by Vera Rubin.
In modern times, it was astronomer Fritz Zwicky, in the 1930s, who made the first observations of what we now call dark matter. His 1933 observations of the Coma Cluster of galaxies seemed to indicated it has a mass 500 times more than that previously calculated by Edwin Hubble. Furthermore, this extra mass seemed to be completely invisible. Although Zwicky’s observations were initially met with much skepticism, they were later confirmed by other groups of astronomers.

Thirty years later, astronomer Vera Rubin provided a huge piece of evidence for the existence of dark matter. She discovered that the centers of galaxies rotate at the same speed as their extremities, whereas, of course, they should rotate faster. Think of a vinyl LP on a record deck: its center rotates faster than its edge. That’s what logic dictates we should see in galaxies too. But we do not. The only way to explain this is if the whole galaxy is only the center of some much larger structure, as if it is only the label on the LP so to speak, causing the galaxy to have a consistent rotation speed from center to edge.
__________________________________________________________________________________

They’ll also continue their studies into unknown aspects of the universe: new particles, interactions and physics principles.

In addition to Bloom, Nebraska physicists Dan Claes, Frank Golf and Ilya Kravchenko conduct research alongside national and international counterparts at CERN.

“At Nebraska, our research in physics has been a strength for decades, and this NSF grant recognizes that, along with our demonstrated ability to provide leadership on the international stage,” said Chancellor Ronnie Green. “We embrace yet another opportunity to collaborate with colleagues around the world under the leadership of Dr. Ken Bloom to advance on these grand challenges in physics.”

The CMS Operations Program affords hundreds of postdoctoral researchers and students the opportunity to participate in particle physics research using the world’s most advanced instruments. It also helps fund QuarkNet, a longstanding program that partners high school teachers with particle physics scientists to bring innovative research into classrooms.

For Bloom, who’s spent much of his career conducting research in top-quark physics, weak particle interactions and the Higgs boson, this project is an opportunity to give back to a research community he’s been a part of for more than 30 years. He views it as an act of community service and a chance to pass the baton to up-and-coming physicists who will lead the next generation of discoveries.

“I’m always looking for ways to make people’s lives better in this field,” he said. “How can we do things that will impact a lot of people and help them get their science done? This is what the operations program is, ultimately. If I can do things that will help other people pursue their science ideas, then that’s a useful contribution.”

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The University of Nebraska–Lincoln (US) is a public research university in the city of Lincoln, in the state of Nebraska in the Midwestern United States. It is the state’s oldest university, and the largest in the University of Nebraska system.

The state legislature chartered the university in 1869 as a land-grant university under the 1862 Morrill Act, two years after Nebraska’s statehood into the United States. Around the turn of the 20th century, the university began to expand significantly, hiring professors from eastern schools to teach in the newly organized professional colleges while also producing groundbreaking research in agricultural sciences. The “Nebraska method” of ecological study developed here during this time pioneered grassland ecology and laid the foundation for research in theoretical ecology for the rest of the 20th century. The university is organized into eight colleges on two campuses in Lincoln with over 100 classroom buildings and research facilities.

Its athletic program, called the Cornhuskers, is a member of the Big Ten Conference. The Nebraska football team has won 46 conference championships, and since 1970, five national championships. The women’s volleyball team has won four national championships along with eight other appearances in the Final Four. The Husker football team plays its home games at Memorial Stadium, selling out every game since 1962. The stadium’s capacity is about 92,000 people, larger than the population of Nebraska’s third-largest city.

From CERN (CH) ATLAS : “Detectors for a new era of ATLAS physics”

European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) [CERN]

Iconic view of the European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire](CH)CERN ATLAS detector

CERN ATLAS another view Image Claudia Marcelloni ATLAS CERN

From CERN (CH) ATLAS

8 November, 2021
Katarina Anthony

NSW “C” enters the ATLAS surface hall, located just above the experiment, on 14 October 2021. Image: CERN.

The High-Luminosity upgrade of the Large Hadron Collider (HL-LHC) will dramatically increase the rate of collisions in the ATLAS experiment. While offering an opportunity for physicists to explore some of the rarest processes in the universe, the large collision rate brings new challenges – in particular, higher radiation levels and significantly more data. The ATLAS collaboration is adapting to deal with these challenges by upgrading all parts of its detectors with new, state-of-the-art instruments.

“The Muon New Small Wheels (NSW) are the first new detectors in ATLAS specifically designed to handle high-luminosity conditions,” says ATLAS Spokesperson Andreas Hoecker. “The installation of the second – and final – NSW follows nearly a decade of dedicated efforts by ATLAS members, who designed, constructed and assembled this high-tech muon detector from scratch.”

Cutting-edge technology

The ATLAS NSW system is made up of two wheel-shaped detectors sitting at opposite ends of the experimental cavern. Named in comparison to ATLAS’s 25-metre “big wheel” detectors, each NSW weighs more than 100 tonnes and is nearly 10 metres in diameter.

More important than size is function. The NSW detectors are at the forefront of detector design using two innovative gaseous detector technologies: micromegas (MM) and small-strip thin-gap chambers (sTGC). These provide both fast and precise muon-tracking capabilities. “The improved spatial resolution allowed by the NSW will be especially critical for the ATLAS “trigger”, the system that decides which collision events to store and which to discard. The trigger will rely on the NSW’s excellent resolution to confirm whether a particle originated from the interaction point, thus reducing our chances of saving data from unwanted background events,” says Mario Antonelli, NSW Phase 1 Upgrade Project Leader.

The readout capabilities of the overall system are staggering: two million MM readout channels and 350,000 sTGC electronic readout channels. Each wheel has 16 sectors, each containing two layers of MM and sTGC chambers with four measurement planes apiece, providing the physicists with useful redundancy as they trace a muon’s track through the detectors.

Assembly of the NSW chambers at CERN. Image: CERN.

The dance of detectors

While 2021 has seen the NSW detectors journey underground, this was not their first time on the move. “The NSW effort was multinational, with members from across the global ATLAS collaboration contributing to construction and design,” says Philipp Fleischmann, ATLAS Muon System Project Leader.

After the original wheels were officially retired, NSW “A” was driven from Building 191 to the ATLAS surface hall on 6 July and, six days later, lowered into the ATLAS cavern where it was moved into its final position between the calorimeter endcap cryostat and the endcap toroid magnets. This momentous occasion was repeated for the NSW “C” four months later, as it was lowered into the ATLAS cavern on 4 November.

“That the team managed to keep the project on track despite a global pandemic and the tragic loss of their project leader, Stephanie Zimmermann, is a testament to their incredible talent and dedication,” says ATLAS Technical Coordinator Ludovico Pontecorvo.

NSW “A” positioned in place inside the ATLAS experiment. Image: CERN.

New wheels in motion

The NSW detectors will be instrumental in Run 3 data taking, as a moderate increase in luminosity is already planned for the LHC. While waiting to see the wheels in action, the ATLAS collaboration turns its focus to the next major upgrades of the experiment. “The next long shutdown of the LHC (LS3, scheduled for 2025) will be the last before the HL-LHC begins operation,” says Francesco Lanni, ATLAS Upgrade Coordinator. “We have a lot to accomplish in the intervening years, including the construction and assembly of an entire new inner tracking system. But with each new upgrade, we get one step closer to the next chapter of LHC physics and the exciting discoveries that may lay within.”

See the full article here .

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CERN Courier (CH)

Quantum Diaries

European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire(CH) map

CERN LHC underground tunnel and tube.

SixTRack CERN LHC particles

From CERN (CH) CMS: “A triple treat from CMS”

European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) [CERN]

European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) (EU) [CERN] CMS

From The European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) [CERN] CMS

29 October, 2021
Ana Lopes

In a first for particle physics, the CMS collaboration has observed three J/ψ particles emerging from a single collision between two protons.

It’s a triple treat. By sifting through data from particle collisions at the Large Hadron Collider (LHC), the CMS collaboration has seen not one, not two but three J/ψ particles emerging from a single collision between two protons. In addition to being a first for particle physics, the observation opens a new window into how quarks and gluons are distributed inside the proton.

The J/ψ particle is a special particle. It was the first particle containing a charm quark to be discovered, winning Burton Richter and Samuel Ting a Nobel prize in physics and helping to establish the quark model of composite particles called hadrons.

Experiments including ATLAS, CMS and LHCb at the LHC have previously seen one or two J/ψ particles coming out of a single particle collision, but never before have they seen the simultaneous production of three J/ψ particles – until the new CMS analysis.

The trick? Analysing the vast amount of high-energy proton–proton collisions collected by the CMS detector during the second run of the LHC, and looking for the transformation of the J/ψ particles into pairs of muons, the heavier cousins of the electrons.

From this analysis, the CMS team identified five instances of single proton–proton collision events in which three J/ψ particles were produced simultaneously. The result has a statistical significance of more than five standard deviations – the threshold used to claim the observation of a particle or process in particle physics.

These three-J/ψ events are very rare. To get an idea, one-J/ψ events and two-J/ψ events are about 3.7 million and 1800 times more common, respectively. “But they are well worth investigating,” says CMS physicist Stefanos Leontsinis, “A larger sample of three-J/ψ events, which the LHC should be able to collect in the future, should allow us to improve our understanding of the internal structure of protons at small scales.”

See the full article here.

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Meet CERN (CH) in a variety of places:

Quantum Diaries

Cern Courier (CH)

European Organization for Nuclear Research (Organisation européenne pour la recherche nucléaire)(EU) CMS

From Symmetry: “Photographing the HL-LHC” Photo Essay

From Symmetry

08/31/21
Samuel Hertzog

A CERN photographer and videographer writes about his experiences documenting the ongoing upgrade that will turn the Large Hadron Collider into the High-Luminosity LHC.

“It’s August 2019, and I’m a photographer employed by CERN to create audiovisual content for CERN’s internal and external communication. Today a colleague and I are photographing the ongoing civil engineering for new passages, caverns and shafts that will enlarge CERN’s subterranean accelerator complex. When completed, they will house the powering, protection and cryogenic systems for the High-Luminosity LHC. These upgrades will increase the collision rate by a factor of five beyond the LHC’s design value and enable the experiments to search for new physics and phenomena that were previously out of reach.

A security officer guides us, making sure we stay out of the way of the heavy machinery while he shows us his favorite spots. The lighting is dim, which makes navigating the rocky and uneven pathway even more treacherous.

Photo by Maximilien Brice.

Courtesy of Samuel Hertzog and Jules Ordan.

“Our mission is to collect photos and video footage that both convey the feel of the place and document the action. In just a short time, with limited recording gear and the addition of bulky gloves, boots, masks and protective glasses, we rush to set up our shots.

Two things stand out: The scale of the place, and how rough an area it is. This, to a photographer, is a sign that it is time to break out the wide-angle lenses and get right up close to the workers. We want to create an immersive feeling for the viewer, a sense that they are right there with us taking in the entire scene.

Courtesy of Samuel Hertzog and Jules Ordan.

“Before coming to CERN in winter 2019, I primarily focused on wildlife photography and filmmaking. Working at CERN is unlike anything I’ve done before. I often say shooting the CERN caverns is where a top photographer can really make their mark. You are faced with huge structures but very little room to maneuver. It’s dark, so you need to hold for long exposures. But there are also lots of people and machines moving at all times. To balance all these factors at once is a real test of your skills.

Toward the end of 2019, the workers break through the wall and connect the new tunnel to the one that holds the LHC. Project leaders and the Director General of CERN hold a ceremony to commemorate the moment. The heads of CERN dress in work suits and descend the shaky metallic steps to pose for a photo and sit for a short interview under bright lights we set up for the occasion. It feels almost like being in a photo studio 100 meters underground.

Courtesy of Samuel Hertzog and Jules Ordan.

“In May 2021—18 months after the subterranean photoshoot—we return to the HL-LHC tunnels. The crews have been working 24/7 to get the tunnel construction completed before the LHC restart in Spring 2022. We are told that dust is no longer the issue, but vertigo might be. The temporary elevator is being replaced, so our way down is essentially a large bucket suspended by a rope. No room for unsteady nerves on this site!

Courtesy of Samuel Hertzog and Jules Ordan

“When we reach the bottom, the tunnel is radically different. We find ourselves in a clean, white entrance hall, with our path illuminated at regular intervals by elegant blue lights.

Courtesy of Samuel Hertzog and Jules Ordan.

“The challenge is now less technically extreme. Creatively, however, this is a whole new game. We still have the heavy machinery and workers in high-vis uniforms. But otherwise, the surroundings are pure science fiction. We respond with a change in style, paying attention to symmetry, proportions and structure to convey the modern, elegant environment.

Courtesy of Samuel Hertzog and Jules Ordan.

“It is a photographer’s duty to be adaptable and quick to come up with new ideas when documenting, and CERN’s ever-changing environments certainly test those skills. Conditions and constraints ultimately bring out creativity. It is remarkable to me to look back and see not only the evolution the location but also of my own perspective.”

See the full article here .

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Please help promote STEM in your local schools.

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Symmetry is a joint Fermilab/SLAC publication.

From Symmetry: “Teaching a particle detector new tricks”

From Symmetry

08/26/21
Sarah Charley

Scientists hoping to find new, long-lived particles at the Large Hadron Collider recently realized they may already have the detector to do it.

European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire(CH) CMS Detector

European Organization for Nuclear Research (Organisation européenne pour la recherche nucléaire)(EU) CMS Detector

Physicist Cristián Peña grew up in Talca, a small town a few hours south of Santiago, Chile. “The Andes run all the way through the country,” he says. “No matter where you look, you always have the mountains.”

At the age of 13, he first aspired to climb them.

Over the years, as his mountaineering skills grew, so did his inventory of tools. Ice axes, crampons and ropes expanded his horizons.

In Peña’s work as a scientist at the DOE’s Fermi National Accelerator Laboratory (US), he applies this same mindset: He creates the tools his experiment needs to explore new terrain.

“Detector work is key,” he says.

Peña’s current focus is the CMS detector, one of two large, general-purpose detectors at the Large Hadron Collider. Peña and colleagues want to use CMS to search for a class of theoretical particles with long lifetimes.

While working through the problem, they realized that an ideal long-lived particle detector is already installed inside CMS: the CMS muon system. The question was whether they could hack it to do something new.

Courtesy of CMS Collaboration.

Long-lived particles

When scientists designed the CMS detector in the 1990s, they had the most popular and mathematically resilient models of particle physics in mind. As far as they knew, the most interesting particles would live just a fraction of a fraction of a second before transforming into well understood secondary particles, such as photons and electrons. CMS would catch signals from those secondary particles and use them as a trail back to the original.

The prompt-decay assumption worked in the search for Higgs bosons. But scientists are now realizing that this “live fast, die young” model might not apply to every interesting thing that comes out of a collision at the LHC. Peña says he sees this as a sign that it’s time for the experiment to evolve.

“If you’re a little kid and you walk a mile in the forest, it’s all completely new,” he says. “Now we have more experience and want to push new frontiers.”

For CMS scientists, that means finding better ways to look for particles with long lifetimes.

Long-lived particles are not a radical new concept. Neutrons, for example, live for about 14 minutes outside the confines of an atomic nucleus. And protons are so long-lived that scientists aren’t sure whether they decay at all. If undiscovered particles are moving into the detector before becoming visible, they could be hiding in plain sight.

“Previously, we hadn’t really thought to look for long-lived particles,” says Christina Wang, a graduate student at The California Institute of Technology (US) working on the CMS experiment. “Now, we have to find new ways to use the CMS detector to see them.”

A new idea

Peña was thinking about long-lived particles while attending a conference in Aspen, Colorado, in March 2019.

“There were a bunch of whiteboards, and we were throwing around ideas,” he says. “In that type of situation, you go with the vibe. There’s a lot of creativity and you start thinking outside the box.”

Peña and his colleagues visualized what an ideal long-lived particle detector might look like. They would need a detector that was far from the collision point. And they would need shielding to filter out the secondary particles that are the stars of the show in traditional searches.

“When you look at the CMS muon system,” Peña says, “that’s exactly what it is.”

Muons, often called the heavier cousins of electrons, are produced during the high-energy collisions inside the LHC. A muon can travel long distances, which is why CMS and its sister experiment, ATLAS, have massive detectors in their outer layers solely dedicated to capturing and recording muon tracks.

Peña ran a quick simulation to see if the CMS muon system would be sensitive to the firework-like signatures of long-lived particles. “It was quick and dirty,” he says, “but it looked feasible.”

After the conference, Peña returned to his regular activities. A few months later, Caltech rising sophomore Nathan Suri joined Professor Maria Spiropulu’s lab as a summer student, working with Wang. Peña, who was also collaborating with Spiropulu’s research group, assigned Suri the muon detector idea as his summer project.

“I was always encouraged to give ideas to young, talented people and let them run with it,” Peña says.

Suri was excited to take on the challenge. “I was in love with the originality of the project,” he says. “I was eager to sink my teeth into it.”

Testing the concept

Suri started by scanning event displays of simulated long-lived particle decays to look for any shared visual patterns. He then explored the original technical design report for the CMS muon detector system to see just how sensitive it could be to these patterns.

“Looking at the unique detector design and highly sensitive elements, I was able to realize what a powerful tool it was,” he says.

By the end of the summer, Suri’s work had shown that not only was it feasible to use the muon system to detect long-lived particles, but that CMS scientists could use pre-existing LHC data to get a jump start on the search.

“At this point, the floodgates opened,” Suri says.

In fall 2019, Wang took the lead on the project. Suri had shown that the idea was possible; Wang wanted to know if it was realistic.

So far, they had been working with processed data from the muon system, which was not adapted to the kind of search they wanted to do. “All the reconstruction techniques used in the muon system are optimized to detect muons,” Wang says.

Wang, Peña and Caltech Professor Si Xie set-up a Zoom meeting with muon system experts to ask for advice.

“They were really surprised that we wanted to use the muon system to infer long-lived particles,” Wang says. “They were like, ‘It’s not designed to do that.’ They thought it was a weird idea.”

The experts suggested the team should try looking at the raw data instead.

Doing so would require extracting unprocessed information from tapes and then developing new software and simulations that could reinterpret thousands of raw detector hits. The task would be arduous, if not impossible.

After the muon system experts left the call, Wang remembers, “we were still in the Zoom room and like, ‘Do we want to continue this?’”

She says it was not a serious question. Of course they did.

A trigger of their own

In fall 2020, Martin Kwok started a postdoctoral position at Fermilab. “We’re encouraged to talk to as many groups as we can and think about what we want to work on most,” he says.

He met with Fermilab researcher Artur Apresyan, who told him about the collaboration with Caltech to convert the CMS muon system into a long-lived particle detector. “It was immediately attractive,” Kwok says. “It’s not very often that we get to explore new uses for our detector.”

Wang and her colleagues had forged ahead with the idea, extracting, processing, and analyzing raw data recorded by the CMS muon system between 2016 and 2018.

It had worked, but the dataset they had available to study was not ideal.

The LHC generates around a billion collisions every second—much more than scientists can record and process. So scientists use filters called triggers to quickly evaluate and sort fresh collision data.

For every billion collisions, only about 1000 are deemed “interesting” by the triggers and saved for further analysis. Wang and her colleagues had determined the filters closest to what they were looking for were the ones programmed to look for signs of dark matter.

Apresyan pitched to Kwok that he could design a new trigger, one actually meant to look for signs of long-lived particles. They could install it in the CMS muon system before the LHC restarts operation in spring 2022.

With a dedicated trigger, they could increase the number of events deemed “interesting” for long-lived particle searches by up to a factor of 30. “It’s not often that we see a 30-times increase in our ability to capture potential signal events,” Kwok says.

Kwok was up for the challenge. And it was a challenge.

“The price of doing something different—of doing something innovative—is that you have to invent your own tools,” Kwok says.

The CMS collaboration consists of thousands of scientists all using collective research tools that they developed and honed over the last two decades. “It’s a bit like building with Legos,” Kwok says. “All the pieces are there, and depending on how you use and combine them, you can make almost anything.”

But developing this specialized trigger was less like picking the right Legos and more like creating a new Lego piece out of melted plastic.

Kwok dug into the experiment’s archives in search of his raw materials. He found an old piece of software that had been developed by CMS but rarely used. “This left-over tool that faded out of popularity turned out to be very handy,” he says.

Kwok and his collaborators also had to investigate if integrating a new trigger into the muon system was even possible. “There’s only so much bandwidth in the electronics to send information upstream,” Kwok says.

“I’m thankful that our collaboration ancestors designed the CMS muon system with a few unused bits. Otherwise, we would have had to reinvent the whole triggering scheme.”

What started as a feasibility study has now evolved into an international effort, with many more institutions contributing to data analysis and trigger R&D. The US institutions contributing to this research are funded by the Department of Energy (US) and the National Science Foundation (US).

“Because we don’t have dedicated long-lived particle triggers yet, we have a low efficiency,” Wang says. “But we showed that it’s possible—and not only possible, but we are overhauling the CMS trigger system to further improve the sensitivity.”

The LHC is scheduled to continue into the 2030s, with several major accelerator and detector upgrades along the way. Wang says that to keep probing nature at its most fundamental level, scientists must remain at the frontier of detector technology and question every assumption.

“Then new areas to explore will naturally follow,” she says. “Long-lived particles are just one of these new areas. We’re just getting started.”

See the full article here .

five-ways-keep-your-child-safe-school-shootings

Please help promote STEM in your local schools.

Stem Education Coalition

Symmetry is a joint Fermilab/SLAC publication.