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  • richardmitnick 9:28 pm on August 25, 2021 Permalink | Reply
    Tags: "Two-trap cooling promises antimatter precision", Antimatter, , , , Substantial improvements to studies of antiprotons., The BASE collaboration   

    From European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) [CERN]: “Two-trap cooling promises antimatter precision” 

    Cern New Bloc

    Cern New Particle Event

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

    25 August, 2021
    Mark Rayner

    The BASE collaboration [below] has performed the first demonstration of two-trap sympathetic cooling, promising substantial improvements to studies of antiprotons.

    Cool experiment — Matthew Bohman (left) and Christian Smorra point out the location of the Penning trap where individual protons are cooled in the new two-trap cooling apparatus at the Johannes Gutenberg University Mainz [Johannes Gutenberg-Universität Mainz] (DE) (Image: CERN)

    Picture two children playing on swings in a playground. One is a daredevil, launching themselves high off the ground in big arcs. The other daydreams, swinging gently.

    Now picture the children holding either end of a long spring. Tension in the spring now accelerates the daydreaming child forwards and backwards to follow their friend, whose swings are slowed and shortened.

    This is the principle behind a groundbreaking new technological demonstration reported today in Nature by the BASE collaboration [below] – an international particle-physics collaboration based at CERN’s antimatter factory. The energetic child represents a single proton oscillating inside the magnetic and electric fields of a Penning trap. The daydreamer represents a laser-cooled cloud of beryllium ions inside a second trap. The spring represents a unique innovation by the BASE collaboration: a superconducting resonant electric circuit that transfers energy from the proton to the ions, just as the spring transfers energy from one swing to the other. Smaller swings mean a lower temperature proton and greater precision in experimental studies.

    “This is an important milestone in precision Penning trap spectroscopy,” says BASE deputy spokesperson Christian Smorra of Riken [理研](JP) and the University of Mainz, where the demonstration was performed. “With optimised procedures we should be able to reach particle temperatures of the order of 20 to 50 mK, ideally in cooling times of the order of 10 seconds. Previous methods allowed us to reach 100 mK in 10 hours.”

    The speedy new two-trap cooling procedure promises a huge increase in the statistics that are available to experimenters. It is also a game-changing development for the study of BASE’s main particle of interest: the antiproton. Conventional cooling techniques are difficult to apply to antimatter because it is highly challenging to put matter and antimatter in the same trap. Applying the new technique should allow a significant improvement on BASE’s already world-leading measurements of fundamental properties of antiprotons. Such measurements have the potential to shed light on one of the biggest unanswered questions in fundamental physics: the unexplained surfeit of matter over antimatter in the universe.

    “Our vision is to continually improve the precision of our matter–antimatter comparisons to develop a better understanding of the cosmological matter–antimatter asymmetry,” says BASE spokesperson Stefan Ulmer of RIKEN. “The newly developed technique will become a key method in these experiments, which aim to measure fundamental antimatter constants at the sub-parts-per-trillion level.”

    See the full article here.

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    European Organization for Nuclear Research (Organisation européenne pour la recherche nucléaire)(EU)[CERN] AEGIS.

    CERN FASER is designed to study the interactions of high-energy neutrinos and search for new as-yet-undiscovered light and weakly interacting particles. Such particles are dominantly produced along the beam collision axis and may be long-lived particles, travelling hundreds of metres before decaying. The existence of such new particles is predicted by many models beyond the Standard Model that attempt to solve some of the biggest puzzles in physics, such as the nature of dark matter and the origin of neutrino masses.

    CERN The SPS’s new RF system. Image: CERN

  • richardmitnick 11:44 am on February 19, 2020 Permalink | Reply
    Tags: , Antimatter, , , ,   

    From CERN ALPHA: “ALPHA collaboration at CERN reports first measurements of certain quantum effects in antimatter” 

    Cern New Bloc

    Cern New Particle Event

    From CERN ALPHA-g


    The ALPHA collaboration at CERN has reported the first measurements of certain quantum effects in the energy structure of antihydrogen, the antimatter counterpart of hydrogen. These quantum effects are known to exist in matter, and studying them could reveal as yet unobserved differences between the behaviour of matter and antimatter. The results, described in a paper published today in the journal Nature, show that these first measurements are consistent with theoretical predictions of the effects in “normal” hydrogen, and pave the way for more precise measurements of these and other fundamental quantities.

    “Finding any difference between these two forms of matter would shake the foundations of the Standard Model of particle physics, and these new measurements probe aspects of antimatter interaction – such as the Lamb shift – that we have long looked forward to addressing,” says Jeffrey Hangst, spokesperson for the ALPHA experiment.

    Standard Model of Particle Physics, Quantum Diaries

    “Next on our list is chilling large samples of antihydrogen using state-of-the-art laser cooling techniques. These techniques will transform antimatter studies and will allow unprecedentedly high-precision comparisons between matter and antimatter.”

    The ALPHA team creates antihydrogen atoms by binding antiprotons delivered by CERN’s Antiproton Decelerator with antielectrons, more commonly called “positrons”.

    CERN Antimatter factory – antiproton decelerator main device. Wikepedia

    CERN ALPHA-g experiment being installed at CERN’s Antiproton Decelerator hall. (Image CERN)

    It then confines them in a magnetic trap in an ultra-high vacuum, which prevents them from coming into contact with matter and annihilating. Laser light is then shone onto the trapped atoms to measure their spectral response. This technique helps measure known quantum effects like the so-called fine structure and the Lamb shift, which correspond to tiny splittings in certain energy levels of the atom, and were measured in this study in the antihydrogen atom for the first time. The team previously used this approach to measure other quantum effects in antihydrogen, the latest being a measurement of the Lyman-alpha transition.

    The fine structure was measured in atomic hydrogen more than a century ago, and laid the foundation for the introduction of a fundamental constant of nature that describes the strength of the electromagnetic interaction between elementary charged particles. The Lamb shift was discovered in the same system about 70 years ago and was a key element in the development of quantum electrodynamics, the theory of how matter and light interact.

    The Lamb-shift measurement, which won Willis Lamb the Nobel Prize in Physics in 1955, was reported in 1947 at the famous Shelter Island conference – the first important opportunity for leaders of the American physics community to gather after the war.

    Technical Note:
    Both the fine structure and the Lamb shift are small splittings in certain energy levels (or spectral lines) of an atom, which can be studied with spectroscopy. The fine-structure splitting of the second energy level of hydrogen is a separation between the so-called 2P3/2 and 2P1/2 levels in the absence of a magnetic field. The splitting is caused by the interaction between the velocity of the atom’s electron and its intrinsic (quantum) rotation. The “classic” Lamb shift is the splitting between the 2S1/2 and 2P1/2 levels, also in the absence of a magnetic field. It is the result of the effect on the electron of quantum fluctuations associated with virtual photons popping in and out of existence in a vacuum.

    In their new study, the ALPHA team determined the fine-structure splitting and the Lamb shift by inducing and studying transitions between the lowest energy level of antihydrogen and the 2P3/2 and 2P1/2 levels in the presence of a magnetic field of 1 Tesla. Using the value of the frequency of a transition that they had previously measured, the 1S–2S transition, and assuming that certain quantum interactions were valid for antihydrogen, the researchers inferred from their results the values of the fine-structure splitting and the Lamb shift. They found that the inferred values are consistent with theoretical predictions of the splittings in “normal” hydrogen, within the experimental uncertainty of 2% for the fine-structure splitting and of 11% for the Lamb shift.

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  • richardmitnick 11:52 am on December 25, 2019 Permalink | Reply
    Tags: Antimatter, , BASE Collaboration, , , , ,   

    From RIKEN: “Could the mysteries of antimatter and dark matter be linked?” 

    RIKEN bloc

    From RIKEN

    Nov. 15, 2019


    Chief Scientist
    Stefan Ulmer
    Fundamental Symmetries Laboratory
    Chief Scientist Laboratories

    Jens Wilkinson
    RIKEN International Affairs Division
    Tel: +81-(0)48-462-1225 / Fax: +81-(0)48-463-3687
    Email: pr@riken.jp

    Could the mysteries of antimatter and dark matter be linked?

    Could the profound mysteries of antimatter and dark matter be linked? Thinking that they might be, scientists from the international BASE collaboration, led by Stefan Ulmer of the RIKEN Cluster for Pioneering Research, and collaborators have performed the first laboratory experiments to determine whether a slightly different way in which matter and antimatter interact with dark matter might be a key to solving both mysteries.

    BASE: Baryon Antibaryon Symmetry Experiment

    Dark matter and antimatter are both vexing problems for physicists trying to understand how our world works at a fundamental level.

    The problem with antimatter is that though the Big Bang should have created equal amounts of matter and antimatter, the world we live in is made only of matter. Antimatter is created every day in experiments and even by natural processes such as lightning, but it is quickly annihilated in collisions with regular matter. Predictions show that our understanding of the matter content of the Universe is off by nine orders of magnitude, and no one knows why the asymmetry exists.

    In the case of dark matter, it is known from astronomical observations that some unknown mass is influencing the orbits of stars in galaxies, but no one has been able to determine the exact microscopic properties of these particles. One theory is that they are a type of hypothetical particle known as an axion, which has an important role in explaining the lack of symmetry violation in the strong interaction in the standard model of particle physics.

    The BASE group collaborators wondered whether the lack of antimatter might be because it interacts differently with dark matter, and set out to test this. For the experiment, they used a specially designed device, called a Penning trap, to magnetically trap a single antiproton, preventing it from contacting ordinary matter and being annihilated. They then measured a property of the antiproton called its spin precession frequency. Normally, this should be constant in a given magnetic field, and a modulation of this frequency could be accounted for by an effect mediated by axion-like particles, which are hypothesized dark matter candidates.

    According to the first author of the study, Christian Smorra “For the first time, we have explicitly searched for an interaction between dark matter and antimatter, and though we did not find a difference, we set a new upper limit for the potential interaction between dark matter and antimatter.”

    Looking to the future, Stefan Ulmer of the RIKEN Cluster for Pioneering Research, who is spokesperson for the BASE Collaboration, says, “From now on, we plan to further improve the accuracy of our measurements of the spin precession frequency of the antiproton, allowing us set more and more stringent constraints on the fundamental invariance of charge, parity, and time, and to make the search for dark matter even more sensitive.”

    The work, published in Nature, was carried out by the RIKEN Fundamental Symmetries Laboratory and a working group at the PRISMA+ excellence cluster of the Johannes Gutenberg University Mainz (JGU), which has been active in the search for dark matter. It was conducted at the European Center for Nuclear Research (CERN), using the Antiproton Decelerator (AD). The research also involved scientists from the Max Planck Institute for Nuclear Physics in Heidelberg, CERN, the Johannes Gutenberg University Mainz (JGU), the Helmholtz Institute Mainz (HIM), the University of Tokyo, the GSI Darmstadt, the Leibniz University Hannover and the Physikalisch-Technische Bundesanstalt (PTB) Braunschweig. The research was performed as part of the work of the Max Planck-RIKEN-PTB Center for Time, Constants and Fundamental Symmetries, an international group established to develop high-precisions measurements to better understand the physics of our Universe.

    See the full article here .



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    RIKEN campus

    RIKEN is Japan’s largest comprehensive research institution renowned for high-quality research in a diverse range of scientific disciplines. Founded in 1917 as a private research foundation in Tokyo, RIKEN has grown rapidly in size and scope, today encompassing a network of world-class research centers and institutes across Japan.

  • richardmitnick 12:31 pm on October 10, 2019 Permalink | Reply
    Tags: , Antimatter, , , , , , ,   

    From AAS NOVA: “Should We Blame Pulsars for Too Much Antimatter?” 


    From AAS NOVA

    9 October 2019
    Susanna Kohler

    Artist’s illustration of Geminga, a nearby pulsar that has been proposed to be the source of excess positrons measured at Earth. [Nahks Tr’Ehnl]

    The Earth is constantly being bombarded by cosmic rays — high energy protons and atomic nuclei that speed through space at nearly the speed of light. Where do these energetic particles come from? A new study examines whether pulsars are the source of one particular cosmic-ray conundrum.

    Cosmic rays produced by high-energy astrophysics sources (ASPERA collaboration – AStroParticle ERAnet)

    An Excess of Positrons

    In 2008, our efforts to understand the origin of cosmic rays hit a snag: data from a detector called PAMELA showed that more high-energy positrons were reaching Earth in cosmic rays than theory predicted.

    INFN PAMELA spacecraft

    INFN PAMELA Schematic

    Positrons — the antimatter counterpart to electrons — are thought to be primarily produced by high-energy protons scattering off of particles within our galaxy. These interactions should produce decreasing numbers of positrons at higher energies — yet the data from PAMELA and other experiments show that positron numbers instead go up with increasing energy.

    Something must be producing these extra high-energy positrons — but what?

    Clues from Gamma-rays

    One of the leading theories is that the excess positrons are produced by nearby pulsars — rapidly rotating, magnetized neutron stars. We know that pulsars gradually spin slower and slower over time, losing power as they spew a stream of high-energy electrons and positrons into the surrounding interstellar medium. If the pulsar is close enough to us, positrons produced in and around pulsars might make it to Earth before losing energy to interactions as they travel.

    Women in STEM – Dame Susan Jocelyn Bell Burnell

    Dame Susan Jocelyn Bell Burnell, discovered pulsars with radio astronomy. Jocelyn Bell at the Mullard Radio Astronomy Observatory, Cambridge University, taken for the Daily Herald newspaper in 1968. Denied the Nobel.

    Dame Susan Jocelyn Bell Burnell at work on first plusar chart 1967 pictured working at the Four Acre Array in 1967. Image courtesy of Mullard Radio Astronomy Observatory.

    Dame Susan Jocelyn Bell Burnell 2009

    Dame Susan Jocelyn Bell Burnell (1943 – ), still working from http://www. famousirishscientists.weebly.com

    Observations from the High-Altitude Water Čerenkov (HAWC) Gamma-Ray Observatory show TeV nebulae around pulsars Geminga and PSR B0656+14. But do these sources also have extended GeV nebulae that would provide more direct constraints on positron density? [John Pretz]

    HAWC High Altitude Čerenkov Experiment, located on the flanks of the Sierra Negra volcano in the Mexican state of Puebla at an altitude of 4100 meters(13,500ft), at WikiMiniAtlas 18°59′41″N 97°18′30.6″W. searches for cosmic rays

    Could nearby pulsars produce enough positrons — and could they diffuse out from the pulsars efficiently enough — to account for the high-energy excess we observe here at Earth? A team of scientists now addresses these questions in a new publication led by Shao-Qiang Xi (Nanjing University and Chinese Academy of Sciences).

    To test whether pulsars are responsible for the positrons we see, Xi and collaborators argue that we should look for GeV emission around candidate sources. As the pulsar-produced positrons diffuse outward, they should scatter off of infrared and optical background photons in the surrounding region. This would create a nebula of high-energy emission around the pulsars that glows at 10–500 GeV — detectable by observatories like the Fermi Gamma-ray Space Telescope.

    NASA/Fermi LAT

    NASA/Fermi Gamma Ray Space Telescope

    Fermi LAT gamma-ray count map (top) and residuals after the background is subtracted (bottom) for the region containing Geminga and PSR B0656+14. [Adapted from Xi et al. 2019]

    Two Pulsars Get an Alibi

    Xi and collaborators carefully analyze 10 years of Fermi LAT observations for two nearby pulsars that have been identified as likely candidates for the positron excess: Geminga and PSR B0656+14, located roughly 800 and 900 light-years away from us.

    The result? They find no evidence of extended GeV emission around these sources. The authors’ upper limits on emission from Geminga and PSR B0656+14 give these objects an alibi, suggesting that pulsars can likely account for only a small fraction of the positron excess we observe.

    So where does this leave us? If pulsars are cleared, we will need to look to other candidate sources of high-energy positrons: either other nearby cosmic accelerators like supernova remnants, or more exotic explanations, like the annihilation or decay of high-energy dark matter.


    “GeV Observations of the Extended Pulsar Wind Nebulae Constrain the Pulsar Interpretations of the Cosmic-Ray Positron Excess,” Shao-Qiang Xi et al 2019 ApJ 878 104.

    See the full article here .


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    The mission of the American Astronomical Society is to enhance and share humanity’s scientific understanding of the Universe.

    The Society, through its publications, disseminates and archives the results of astronomical research. The Society also communicates and explains our understanding of the universe to the public.
    The Society facilitates and strengthens the interactions among members through professional meetings and other means. The Society supports member divisions representing specialized research and astronomical interests.
    The Society represents the goals of its community of members to the nation and the world. The Society also works with other scientific and educational societies to promote the advancement of science.
    The Society, through its members, trains, mentors and supports the next generation of astronomers. The Society supports and promotes increased participation of historically underrepresented groups in astronomy.
    The Society assists its members to develop their skills in the fields of education and public outreach at all levels. The Society promotes broad interest in astronomy, which enhances science literacy and leads many to careers in science and engineering.

    Adopted June 7, 2009

  • richardmitnick 7:27 am on June 6, 2019 Permalink | Reply
    Tags: Antimatter, , nEDM-neutron Electric Dipole Moment experiment,   

    From Caltech: “How a Giant ‘Thermos Bottle’ Will Help in Understanding Antimatter” 

    Caltech Logo

    From Caltech

    June 05, 2019

    Whitney Clavin
    (626) 395‑1856

    Members of the nEDM team stand in front of their magnetic cryovessel experimental apparatus in the Synchrotron Building at Caltech. From left to right: Wei Wanchun, research engineer; Marie Blatnick, graduate student, and Brad Filippone, the Francis L. Moseley Professor of Physics and Spokesperson for the nEDM experiment.

    One of the big questions physicists are trying to answer is what happened to all the antimatter in our universe. The universe was born out of a hot soup of both matter and antimatter particles (for example, the antiparticle to an electron is a positron). But something happened billions of years ago to tip the balance to matter, and antimatter disappeared. In fact, if this had not happened, we humans would not be here: when antimatter and matter particles collide, they transform into pure energy.

    To address this mystery, researchers at Caltech are taking part in an ambitious multi-institutional project called the neutron Electric Dipole Moment experiment, or nEDM, funded by the U.S. Department of Energy and the National Science Foundation. The project will culminate in an experiment at the Oak Ridge National Laboratory in Tennessee in about three years. The idea is to look for what is called an electric dipole moment in neutrons—a phenomenon in which the charges within a neutron are such that one side of the neutron is a tad more negative than the other. This distortion, if large enough, could signal a breakdown in a type of symmetry in physics called charge parity, or CP, that is needed to explain the absence of antimatter in the universe.

    Caltech is building a crucial part of the experiment—a giant cryovessel, pictured above, as well as magnetic shielding and coils to produce magnetic fields. The experiment inside the cryovessel, which can be thought of as a giant thermos bottle, will be chilled to temperatures as low as just one-half a degree above absolute zero, or 0.5 Kelvin (-459 degrees Fahrenheit). The idea is to spin ultracold neutrons in a magnetic field inside the chamber, in the same way that MRI machines spin protons in our bodies. An electric field would then be applied, and the researchers would look for very tiny changes in the way the neutrons are spinning—an indication of an electric dipole moment. The sensitivity of the nEDM experiment is equivalent to measuring a distortion in Earth’s diameter of less than one one-hundredth the thickness of a human hair.

    The Caltech team expects to deliver the cryovessel, with its magnetic shielding and magnetic field coils, to Oak Ridge in about a year and a half.

    See the full article here .

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    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”

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  • richardmitnick 11:31 am on January 8, 2019 Permalink | Reply
    Tags: Antimatter, Antiuniverse, , , CPT symmetry, , Our universe has antimatter partner on the other side of the Big Bang say physicists, , , , The entity that respects the symmetry is a universe–antiuniverse pair   

    From physicsworld.com: “Our universe has antimatter partner on the other side of the Big Bang, say physicists” 

    From physicsworld.com

    03 Jan 2019

    (Courtesy: shutterstock/tomertu)

    Our universe could be the mirror image of an antimatter universe extending backwards in time before the Big Bang. So claim physicists in Canada, who have devised a new cosmological model positing the existence of an “antiuniverse” [Physical Review Letters] which, paired to our own, preserves a fundamental rule of physics called CPT symmetry. The researchers still need to work out many details of their theory, but they say it naturally explains the existence of dark matter.

    Standard cosmological models tell us that the universe – space, time and mass/energy – exploded into existence some 14 billion years ago and has since expanded and cooled, leading to the progressive formation of subatomic particles, atoms, stars and planets.

    However, Neil Turok of the Perimeter Institute for Theoretical Physics in Ontario reckons that these models’ reliance on ad-hoc parameters means they increasingly resemble Ptolemy’s description of the solar system. One such parameter, he says, is the brief period of rapid expansion known as inflation that can account for the universe’s large-scale uniformity. “There is this frame of mind that you explain a new phenomenon by inventing a new particle or field,” he says. “I think that may turn out to be misguided.”

    Instead, Turok and his Perimeter Institute colleague Latham Boyle set out to develop a model of the universe that can explain all observable phenomena based only on the known particles and fields. They asked themselves whether there is a natural way to extend the universe beyond the Big Bang – a singularity where general relativity breaks down – and then out the other side. “We found that there was,” he says.

    The answer was to assume that the universe as a whole obeys CPT symmetry. This fundamental principle requires that any physical process remains the same if time is reversed, space inverted and particles replaced by antiparticles. Turok says that this is not the case for the universe that we see around us, where time runs forward as space expands, and there’s more matter than antimatter.

    In a CPT-symmetric universe, time would run backwards from the Big Bang and antimatter would dominate (L Boyle/Perimeter Institute of Theoretical Physics)

    Instead, says Turok, the entity that respects the symmetry is a universe–antiuniverse pair. The antiuniverse would stretch back in time from the Big Bang, getting bigger as it does so, and would be dominated by antimatter as well as having its spatial properties inverted compared to those in our universe – a situation analogous to the creation of electron–positron pairs in a vacuum, says Turok.

    Turok, who also collaborated with Kieran Finn of Manchester University in the UK, acknowledges that the model still needs plenty of work and is likely to have many detractors. Indeed, he says that he and his colleagues “had a protracted discussion” with the referees reviewing the paper for Physical Review Letters [link is above] – where it was eventually published – over the temperature fluctuations in the cosmic microwave background. “They said you have to explain the fluctuations and we said that is a work in progress. Eventually they gave in,” he says.

    In very broad terms, Turok says, the fluctuations are due to the quantum-mechanical nature of space–time near the Big Bang singularity. While the far future of our universe and the distant past of the antiuniverse would provide fixed (classical) points, all possible quantum-based permutations would exist in the middle. He and his colleagues counted the instances of each possible configuration of the CPT pair, and from that worked out which is most likely to exist. “It turns out that the most likely universe is one that looks similar to ours,” he says.

    Turok adds that quantum uncertainty means that universe and antiuniverse are not exact mirror images of one another – which sidesteps thorny problems such as free will.

    But problems aside, Turok says that the new model provides a natural candidate for dark matter. This candidate is an ultra-elusive, very massive particle called a “sterile” neutrino hypothesized to account for the finite (very small) mass of more common left-handed neutrinos. According to Turok, CPT symmetry can be used to work out the abundance of right-handed neutrinos in our universe from first principles. By factoring in the observed density of dark matter, he says that quantity yields a mass for the right-handed neutrino of about 5×108 GeV – some 500 million times the mass of the proton.

    Turok describes that mass as “tantalizingly” similar to the one derived from a couple of anomalous radio signals spotted by the Antarctic Impulsive Transient Antenna (ANITA). The balloon-borne experiment, which flies high over Antarctica, generally observes cosmic rays travelling down through the atmosphere. However, on two occasions ANITA appears to have detected particles travelling up through the Earth with masses between 2 and 10×108 GeV. Given that ordinary neutrinos would almost certainly interact before getting that far, Thomas Weiler of Vanderbilt University and colleagues recently proposed that the culprits were instead decaying right-handed neutrinos [Letters in High Energy Physics].

    Turok, however, points out a fly in the ointment – which is that the CPT symmetric model requires these neutrinos to be completely stable. But he remains cautiously optimistic. “It is possible to make these particles decay over the age of the universe but that takes a little adjustment of our model,” he says. “So we are still intrigued but I certainly wouldn’t say we are convinced at this stage.”

    See the full article here .

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  • richardmitnick 10:24 am on October 11, 2018 Permalink | Reply
    Tags: Antimatter, , , , , , , , , , ,   

    From Don Lincoln via CNN: “The ultimate mystery of the universe” 

    From CNN

    September 21, 2018

    FNAL’s Don Lincoln

    This might win an award for “most obvious statement ever,” but the universe is big. And with its size comes big questions. Perhaps the biggest is “What makes the universe, well…the universe?”
    Researchers have made a crucial step forward in their effort to build scientific equipment that will help us answer that fundamental question.

    An international group of physicists collaborating on the Deep Underground Neutrino Experiment (DUNE) have announced that a prototype version of their equipment, called ProtoDUNE, is now operational.
    ProtoDUNE will validate the technology of the much larger DUNE experiment, which is designed to detect neutrinos, subatomic particles most often created in violent nuclear reactions like those that occur in nuclear power plants or the Sun. While they are prodigiously produced, they can pass, ghost-like, through ordinary matter. There are three distinct types of neutrinos, as different as the strawberry, vanilla, and chocolate flavors of Neapolitan ice cream.

    Further, through the always-confusing rules of quantum mechanics, these three types of neutrinos experience a startling behavior — they literally change their identity. Following the ice cream analogy, this would be like starting to eat a scoop of vanilla and, a few spoonfuls in, it magically changes to chocolate. It is through this morphing behavior that scientists hope to explain why our universe looks the way it does, rather than like a featureless void, full of energy and nothing else.

    View of the interior of the ProtoDUNE experiment

    CERN Proto DUNE Maximillian Brice

    Large enough to encompass a three-story house, ProtoDUNE is located at the CERN laboratory, just outside Geneva, Switzerland. Years in the making, ProtoDUNE is filled with 800 tons of chilled liquid argon, which detects the passage of subatomic particles like neutrinos. Neutrinos hit the nuclei of the argon atoms in the ProtoDUNE detector, causing particles with electrical charge to be produced. Those particles then move through the detector, banging into argon atoms and knocking their electrons off. Scientists then detect the electrons.
    It’s similar to how you can know an airplane recently passed overhead because you observe contrails, the white streaks in the sky it briefly leaves behind. The ProtoDUNE detector has now observed particles coming from space — what scientists call cosmic rays — which has validated the effectiveness of the particle detector.

    Though considerably large, ProtoDUNE pales in comparison to the size of the DUNE apparatus, which is still being developed. DUNE will be based at two locations: Fermi National Accelerator Laboratory (Fermilab), which is America’s flagship particle physics laboratory located just outside Chicago, and the Sanford Underground Research Facility (SURF), located in Lead, South Dakota.

    FNAL LBNF/DUNE from FNAL to SURF, Lead, South Dakota, USA

    Surf-Dune/LBNF Caverns at Sanford

    The biggest part of the DUNE experiment will ultimately consist of four large modules, each of which will be twenty times larger than ProtoDUNE. Because neutrinos interact very rarely with ordinary matter, bigger is better. And with an eighty times increase in volume, the DUNE detector will be able to detect eighty times as many neutrinos as ProtoDUNE.
    These large modules will be located nearly a mile underground at SURF. That depth is required to protect them from the same cosmic rays seen by ProtoDUNE.
    Fermilab will use its highest energy particle accelerator to generate a beam of neutrinos, which it will then shoot through the Earth to the waiting detectors over 800 miles away in western South Dakota.

    This beam of neutrinos will pass through a ProtoDUNE-like detector located at Fermilab to establish their characteristics as they leave the site. When the neutrinos arrive in South Dakota, the much bigger detectors again measure the neutrinos and look to see how much they have changed their identity as they traveled. It’s this identity-changing behavior that DUNE is designed to study. Scientists call this phenomenon “neutrino oscillations” because the neutrinos change from one type to another and then back again, over and over.
    While investigating and characterizing neutrino oscillations is the direct goal of the DUNE experiment, the deeper goal is to use those studies to shed light on one of those fundamental questions of the universe. This will be made possible because the DUNE experiment not only will study the oscillation behavior of neutrinos, it can also study the oscillation of antimatter neutrinos.

    A strong runner-up in the “most obvious statement ever” award is “our universe is made of matter.” But researchers have long known of a cousin substance called “antimatter.”

    Antimatter is the opposite of ordinary matter and will annihilate into pure energy when combined with matter. Alternatively, energy can simultaneously convert into matter and antimatter in equal quantities. This has been established beyond any credible doubt.

    Yet, with that observation, comes a mystery. Scientists generally accept that the universe came into existence through an event called the Big Bang. According to this theory, the universe was once much smaller, hotter, and full of energy. As the universe expanded, that energy should have converted into matter and antimatter in exactly equal quantities, which leads us to a very vexing question.

    Where the heck is the antimatter?

    Our universe consists only of matter, which means that something made the antimatter of the early universe disappear. Had this not happened, the matter and antimatter would have annihilated, and the universe would consist of nothing more than a bath of energy, without matter — without us.

    Which brings us back to the DUNE experiment. Fermilab will make not only neutrino beams, it will also make antimatter neutrino beams. The exact mix of neutrino “flavors” leaving the Fermilab campus will be established by the closer detector, and then again when they arrive at SURF, so that the changes due to neutrino oscillation can be measured. Then the same process will be done with antimatter neutrinos. If the matter and antimatter neutrinos oscillate differently, that will likely be a huge clue toward answering the question of why the universe exists as it does.

    With the completion of the new ProtoDUNE technology that will be used in the DUNE detector, the race is on to build the full facility. The first of the detector modules is scheduled to begin operations in 2026.

    While Fermilab has long made substantial contributions to the CERN research program, the DUNE experiment marks the first time that CERN has invested in scientific infrastructure in the United States. DUNE is a product of a unified international effort.
    Modern science is truly staggering in its accomplishments. We can cure deadly diseases and we’ve put men on the moon. But perhaps the grandest accomplishment of all is our ability to innovate in our effort to study in detail some of the oldest and most mind-boggling questions of our universe. And, with the success of ProtoDUNE, we’re that much closer to finding the answers.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

  • richardmitnick 9:02 am on August 26, 2018 Permalink | Reply
    Tags: , Antimatter, , , , , , ,   

    From CERN via Science Alert: “Physicists Are Almost Able to Cool Antimatter. Here’s Why That’s a Big Deal” 

    Cern New Bloc

    Cern New Particle Event

    CERN New Masthead

    From CERN


    Science Alert


    26 AUG 2018

    Where is all the antimatter?

    We’re still figuring out what the heck antimatter even is, but scientists are already getting ready to fiddle with it.

    Physicists at the European Organization for Nuclear Research (CERN) are one step closer to cooling antimatter using lasers, a milestone that could help us crack its many mysteries.

    They published their research on Wednesday in the journal Nature.

    Antimatter is essentially the opposite of “normal” matter. While protons have a positive charge, their antimatter equivalents, antiprotons, have the same mass, but a negative charge.

    Electrons and their corresponding antiparticle, positrons, have the same mass — the only difference is that they have different charges (negative for electrons, positive for positrons).

    When a particle meets its antimatter equivalent, the two annihilate one another, canceling the other out.

    In theory, the Big Bang should have produced an equal amount of matter and antimatter, in which case, the two would have just annihilated one another.

    But that’s not what happened — the Universe seems to have way more matter than antimatter.

    Researchers have no idea why that is, and because antimatter is very difficult to study, they haven’t had much recourse for figuring it out.

    And that’s why CERN researchers are trying to cool antimatter off, so they can get a better look.

    Using a tool called the Antihydrogen Laser Physics Apparatus (ALPHA), the researchers combined antiprotons with positrons to form antihydrogen atoms.

    CERN ALPHA Antimatter Factory

    Then, they magnetically trapped hundreds of these atoms in a vacuum and zapped them with laser pulses. This caused the antihydrogen atoms to undergo something called the Lyman-alpha transition.

    “The Lyman-alpha transition is the most basic, important transition in regular hydrogen atoms, and to capture the same phenomenon in antihydrogen opens up a new era in antimatter science,” one of the researchers, Takamasa Momose, said in a university press release.

    According to Momose, this phase change is a critical first step toward cooling antihydrogen.

    Researchers have long used lasers to cool other atoms to make them easier to study. If we can do the same for antimatter atoms, we’ll be better able to study them.

    Scientists can take more accurate measurements, and they might even be able to solve another long-unsettled mystery: figuring out how antimatter interacts with gravity.

    For now, the team plans to continue working toward that goal of cooling antimatter. If they’re successful, they might be able to help unravel mysteries with answers critical to our understanding of the Universe.

    See the full article here.

  • richardmitnick 5:32 pm on August 22, 2018 Permalink | Reply
    Tags: , Antihydrogen atom, Antimatter, , , Finding any slight difference between the behaviour of antimatter and matter would rock the foundations of the Standard Model of particle physics and perhaps cast light on why the universe is made up , , Lyman-alpha electronic transition, ,   

    From CERN: “ALPHA experiment takes antimatter to a new level” 

    Cern New Bloc

    Cern New Particle Event

    CERN New Masthead

    From CERN

    22 Aug 2018
    Ana Lopes

    Jeffrey Hangst, spokesperson for the ALPHA experiment, next to the experiment. (Image: Maximilien Brice, Julien Ordan/CERN)

    CERN ALPHA Antimatter Factory

    In a paper published today in the journal Nature, the ALPHA collaboration reports that it has literally taken antimatter to a new level. The researchers have observed the Lyman-alpha electronic transition in the antihydrogen atom, the antimatter counterpart of hydrogen, for the first time. The finding comes hot on the heels of recent measurements by the collaboration of another electronic transition, and demonstrates that ALPHA is quickly and steadily paving the way for precision experiments that could uncover as yet unseen differences between the behaviour of matter and antimatter.

    The Lyman-alpha (or 1S-2P) transition is one of several in the Lyman series of electronic transitions that were discovered in atomic hydrogen just over a century ago by physicist Theodore Lyman. The transition occurs when an electron jumps from the lowest-energy (1S) level to a higher-energy (2P) level and then falls back to the 1S level by emitting a photon at a wavelength of 121.6 nanometres.

    It is a special transition. In astronomy, it allows researchers to probe the state of the medium that lies between galaxies and test models of the cosmos. In antimatter studies, it could enable precision measurements of how antihydrogen responds to light and gravity. Finding any slight difference between the behaviour of antimatter and matter would rock the foundations of the Standard Model of particle physics and perhaps cast light on why the universe is made up almost entirely of matter, even though equal amounts of antimatter should have been produced in the Big Bang.

    The Standard Model of elementary particles (more schematic depiction), with the three generations of matter, gauge bosons in the fourth column, and the Higgs boson in the fifth.

    Standard Model of Particle Physics from Symmetry Magazine

    The ALPHA team makes antihydrogen atoms by taking antiprotons from CERN’s Antiproton Decelerator (AD) and binding them with positrons from a sodium-22 source. It then confines the resulting antihydrogen atoms in a magnetic trap, which prevents them from coming into contact with matter and annihilating. Laser light is then shone onto the trapped atoms to measure their spectral response. The measurement involves using a range of laser frequencies and counting the number of atoms that drop out of the trap as a result of interactions between the laser and the trapped atoms.

    The ALPHA collaboration has previously employed this technique to measure the so-called 1S-2S transition. Using the same approach and a series of laser wavelengths around 121.6 nanometres, ALPHA has now detected the Lyman-alpha transition in antihydrogen and measured its frequency with a precision of a few parts in a hundred million, obtaining good agreement with the equivalent transition in hydrogen.

    This precision is not as high as that achieved in hydrogen, but the finding represents a pivotal technological step towards using the Lyman-alpha transition to chill large samples of antihydrogen using a technique known as laser cooling. Such samples would allow researchers to bring the precision of this and other measurements of antihydrogen to a level at which any differences between the behaviour of antihydrogen and hydrogen might emerge.

    “We are really excited about this result,” says Jeffrey Hangst, spokesperson for the ALPHA experiment. “The Lyman-alpha transition is notoriously difficult to probe – even in ‘normal’ hydrogen. But by exploiting our ability to trap and hold large numbers of antihydrogen atoms for several hours, and using a pulsed source of Lyman-alpha laser light, we were able to observe this transition. Next up is laser cooling, which will be a game-changer for precision spectroscopy and gravitational measurements.”

    See the full article here.

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Meet CERN in a variety of places:

    Quantum Diaries

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    CERN LHC Grand Tunnel

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