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  • richardmitnick 10:33 am on November 27, 2014 Permalink | Reply
    Tags: , , , New York University, , Particle Physics   

    From phys.org: “It’s particle-hunting season! NYU scientists launch Higgs Hunters Project” 

    physdotorg
    phys.org

    November 26, 2014
    No Writer Credit

    New York University scientists and their colleagues have launched the Higgs Hunters project, which will allow members of the general public to study images recorded at the Large Hadron Collider and to help search for previously unobserved particles.

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    A graphic shows particle traces extending from a proton-proton collision at the Large Hadron Collider in 2012. The event shows characteristics expected from the decay of the Standard Model Higgs boson to a pair of photons

    CERN LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC at CERN

    The Higgs Hunters project follows the successful 2012 discovery of the famous Higgs boson particle, a sub-atomic particle that plays a key role in our understanding of the Universe, at the CERN laboratory near Geneva, where the collider is based.

    In 2013, Peter Higgs and François Englert received the Nobel Prize for Physics in recognition of their work to develop the theory of what is now known as the Higgs field, which gives elementary particles mass.

    The project will also include researchers from the University of Oxford, the University of Birmingham, the Zooniverse project, and the ATLAS experiment at CERN.

    CERN ATLAS New
    ATLAS at CERN’s LHC

    “Writing computer algorithms to identify these particles is tough, so we’re excited to see how much better we can do when people help us with the hunt,” observes Andy Haas, an assistant professor of physics at NYU and one of the project’s collaborators.

    “Having found the Higgs Boson particle, now we want to know how it works,” adds Alan Barr, a professor of particle physics at the University of Oxford, and lead scientist of the Higgs Hunters project. “To do that, we’d like you to look at these pictures of collisions and tell us what you can see.”

    The project scientists are searching for previously unobserved microscopic particles that might be created when the Higgs Boson particle decays. The new particles are predicted to leave tell-tale tracks inside the ATLAS experiment, which computer programs find difficult to identify, but which human eyes can often pick out.

    A successful detection would be a huge leap forward for particle physics, researchers say, as any new particles would lie beyond the “Standard Model” – the current best theory of the fundamental constituents of the universe.

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

    For more, please visit http://www.higgshunters.org .

    The project was funded by a Google Global Impact Award, the Science and Technology Research Council of the United Kingdom, and the National Science Foundation, which supports ATLAS work at NYU that includes research and education.

    See the full article here.

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    About Phys.org in 100 Words

    Phys.org™ (formerly Physorg.com) is a leading web-based science, research and technology news service which covers a full range of topics. These include physics, earth science, medicine, nanotechnology, electronics, space, biology, chemistry, computer sciences, engineering, mathematics and other sciences and technologies. Launched in 2004, Phys.org’s readership has grown steadily to include 1.75 million scientists, researchers, and engineers every month. Phys.org publishes approximately 100 quality articles every day, offering some of the most comprehensive coverage of sci-tech developments world-wide. Quancast 2009 includes Phys.org in its list of the Global Top 2,000 Websites. Phys.org community members enjoy access to many personalized features such as social networking, a personal home page set-up, RSS/XML feeds, article comments and ranking, the ability to save favorite articles, a daily newsletter, and other options.

     
  • richardmitnick 11:57 am on November 25, 2014 Permalink | Reply
    Tags: , , , , , Particle Physics   

    From Times Beacon record via BNL: “BNL’s Pleier takes next steps after Higgs-boson” 

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    Brookhaven Lab

    November 19, 2014
    Daniel Dunaief

    mp
    Marc-Andre Pleier photo from BNL

    While the United States was celebrating Independence Day two years ago, a group of people were cheering the discovery of something they had spent almost half a century seeking. Physicists around the world were convinced the so-called Higgs boson particle existed, but no one had found clear-cut evidence of it.

    At a well-attended press conference, scientists hailed the discovery, while recognizing the start of a new set of experiments and questions.

    As a part of the ATLAS team, Marc-Andre Pleier knew what the group was set to announce. He was very excited “to see the signal confirmed by an independent measurement.” Two years later, Pleier, a physicist at Brookhaven National Laboratory and a part of a group of more than 3,000 scientists from around the world, are tackling the next set of questions.

    ca

    The discovery “points to the Standard Model [of particle physics] being correct, but to know this we need to understand this new particle and its properties a lot better than we do now.”

    s,
    The Standard Model of elementary particles, with the three generations of matter, gauge bosons in the fourth column, and the Higgs boson in the fifth.

    According to the Standard Model of particle physics, the Big Bang beginning to the universe should have created equal parts matter and antimatter. If it did, the two opposite energies would have annihilated each other into light. An imbalance, however, resulted in a small fraction of matter surviving, forming the visible universe. The origin of this imbalance, however, is unknown, Pleier said.

    “We know the Standard Models is incomplete,” he said, because there are observations of dark matter, dark energy and the antimatter/matter asymmetry in the universe that can’t be explained by this model. “We can test this” next chapter.

    Cosmic Microwave Background  Planck
    Cosmic Background Radiation per ESA/Planck

    The process Pleier studies allows him to test whether the particle is doing its job as expected. In addition to analyzing data, Pleier also has “major responsibility in upgrading the detector,” said Hong Ma, a group leader in the Physics Department at BNL who recruited Pleier to join BNL in 2009.

    Scientists at the [Large] Hadron Collider in Switzerland and at BNL and elsewhere are studying interactions that are incredibly rare among particles.

    CERN LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC at CERN

    Pleier is searching for interactions of vector bosons, which have spin values of one and are extremely large in the world of bosons. He is looking for cases where two W bosons interact with each other.

    “Only one event out of a hundred trillion events will be of interest to me,” said Pleier. Comparing those numbers to the world of biology, Pleier likened that to finding a single cell in an entire human body.

    In 2012, the Hadron Collider produced 34 such interactions. The collider produces about 40 million pictures per second. To find the ones that might hold promising information, scientists like Pleier need to use a computing grid. BNL is one of only 10 tier 1 centers for ATLAS and the only one in the United States. Thus far, scientists have been able to look at these collisions from energies at 8 trillion electron volts. They hope to measure similar data at 13 trillion electron volts next year.

    Ma said the increased energy of the collider will “put the Standard Model to an unprecedented level of tests,” allowing scientists to “measure the properties of Higgs boson to a higher precision.”

    Growing up in Germany, Pleier said he loved playing with Legos to see how things worked. He helped fix his own toys. When he was older, he worked to repair a motor bike his uncle had.

    What he’s doing now, he said, is exploring the fundamental building blocks of matter and their interactions. He likened it to examining the “construction kit” for the universe. While he’s a physicist, Pleier explained that he’s a Christian. “Some people think it has to be in conflict, but, for me, it clearly is not,” he said. “Each discovery adds to my admiration for God’s creation.”

    A resident of Middle Island, Pleier lives with his wife Heather, an English teacher who is staying home for now to take care of their three children.

    Pleier and Ma emphasized that the work at the collider is a collaborative effort involving scientists from institutions around the world.

    Michael Kobel, a professor at TU Dresden, head of the Institute for Particle Physics and Dean of Studies in the Department of Physics who has known Pleier for about nine years, likened the process of studying the high energy particles to exploring a cave, where scientists “get more light to look deeper” into areas that were in the dark before. Researchers, he said, are just entering this cave of knowledge, with “a lot of corners yet to be explored.”

    See the full article here.

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    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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  • richardmitnick 7:47 pm on November 24, 2014 Permalink | Reply
    Tags: , Nigel Lockyer, Particle Physics, thestar.com   

    From thestar.com: “Basic science is the centre of gravity, says particle physics lab chief “ 

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    thestar.com

    November 24, 2014
    Kate Allen

    Toronto-raised Nigel Lockyer, head of Fermilab, the U.S.’s premier particle physics lab and accelerator, talks about dark matter and how Canada funds scientific research.

    nl
    Nigel Lockyer

    As a kid growing up in North York, Nigel Lockyer earned his keep as a Toronto Star paperboy. He has moved up in the world a little since then. After spending six years as the director of TRIUMF, Canada’s national particle and nuclear physics lab, he was hired away last year to become director of Fermilab, the U.S.’s premier particle physics lab and accelerator. His first degree was a bachelor of science in physics from York University, and this week he returned to Toronto to accept the school’s most distinguished alumni award.

    The Star sat down with its former employee to chat dark matter, balancing science and hockey, and whether the Canadian government supports basic research.

    S.The discovery of the Higgs boson captivated the general public. What are some of the potential discoveries that could be made — in our lifetimes or in our grandchildren’s — that have the potential to be as big of a hit?

    L.I think the world changes the day somebody announces we have observed dark matter. We have all these experiments out there looking for dark matter, trying to produce dark matter, they’re looking for it under the ground, they’re looking for it with satellites and so on. It’s just a question of: where is it?

    I think the astronomers know for sure it’s out there. And we certainly believe there’s nothing special about our galaxy, it’s one of those galaxies that has lots of dark matter and our earth is moving through it. So to me, you find this thing that’s been very mysterious and you’re able to detect it, and then our field, particle physics, would go nuts figuring out how to produce it, how to understand more about it.

    And we don’t know if it’s a single particle or multiple particles or anything at this point. It’s just a complete unknown. All we know are its gravitational properties.

    S.What is it about particle physics that manages to excite the public despite being such a tricky technical field?

    L.Everybody understands that whatever you pick up is made out of something. You have a magnifying glass, you can see the structure of what it is you’re looking at. Particle physics is the extreme of that. You’re looking for the smallest building blocks of space, time, matter.

    S.Fermilab costs what, upwards of $500 million a year to operate?

    L.(Laughs). We don’t advertise those kinds of numbers. It’s $400 (million).

    S.I imagine you’re constantly being pressed to justify Fermilab on an economic basis: jobs created, that kind of thing. Let’s forget about that for a second. What is the worth of basic science?

    L.Basic science generates the ideas of the future, which become applied science. Without basic science you have no input to applied science. The stream dries up.

    Certain organizations understand this extremely well, and others think you can do one or the other, but it’s not true. If you just go back in time, (James Clerk) Maxwell’s understanding that there have to be electromagnetic waves (carries) all the way through to your cellphone today. Quantum mechanics led to the transistor, which led to electronic circuits and so on.

    Everything can point back to basic research. The challenge for governments is how to speed that up and how to pick the winners. Because a lot of stuff that you do ends up not being the home run — or the hat trick, depending on which country you live in.

    S.What can the Canadian government do to nurture the creation of top-level scientists?

    I think they need to fund the science. That’s the bottom line. Take TRIUMF as an example. I spent several years attracting really top people to the laboratory to do research. The government should fund the science those people want to do.

    And they’re always squeezing — they always want to give you less than you need, because that’s how governments function, but I think that’s a mistake. I think Canada can learn from some countries that are very proactive with funding their science. For example, Germany is out in the lead. If you look at Switzerland, great funding for science. If you look at any of the Asian countries now, great funding for science.

    The developing countries are just going nuts with their investment in science, and here we are — and I’ll put Canada and the United States in the same boat, we think alike — saying, “Oh, let’s see, what should we do.” Isn’t it obvious what you should do? Basic science is the future of everything.

    We live in a technological world. Invest in basic science. Just put more money into it. It will work out. And you will keep the best people. Canada is a great country for many other reasons. You don’t have to fight any of those other reasons. You do have to fight the impression that scientific funding is not a high priority for government. And it should be.

    S. Fermilab has lots of grade school students come through (on visits). How can teachers and parents do a better job of increasing scientific literacy in kids — just getting kids excited about science?

    I think you have to make it interesting for them. The same way I got up at five o’clock in the morning to drive my son to hockey, you’ve got to make an effort to take them to events that stimulate them to be interested in science. Around here (in Batavia, Ill.), there seems to be an unusually large number of people interested in robots, and they have all these organizations of kids of different ages from very young all the way through high school where they compete at all these robotic events.

    Going to public lectures with great speakers talking about dark matter — kids are trying to figure out what the world is all about. That’s how I got interested in science, just hearing these crazy ideas.

    And everybody knows this, but teachers are so influential. Whether they’re your public school teachers or your high school or college teachers, having high-quality teachers makes a world of difference to who you produce. Having world-class institutes like York and University of Toronto and Queen’s is another factor in creating great thinkers, whether it’s science or anything else.

    The problem with Canada is that it’s so rich in natural resources that it can always fall back on it rather than developing what I call a knowledge economy mentality. Now the government talks about it, but seems to me that they need to put their money where their mouth is.

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  • richardmitnick 5:56 pm on November 23, 2014 Permalink | Reply
    Tags: , , , , , Particle Physics   

    From LHCb at CERN: “The proton beam knocks at the LHC door” 

    CERN New Masthead

    23 November 2014
    No Writer Credit

    The LHCb collaboration took proton interaction data this weekend

    team
    LHCb is an experiment set up to explore what happened after the Big Bang that allowed matter to survive and build the Universe we inhabit today.

    The proton beam knocked at the LHC’s very solid door this weekend and found it still closed, but nonetheless managed to provide the LHCb collaboration with very interesting data. The CERN accelerator system (see video) is now fully operational, except for the LHC collider itself. This past weekend, CERN accelerator system operators tested the two transfer lines between the SPS and LHC. One of these lines ends with a so-called beam stopper known as the “TED”, located at the end of the line about 300m from the LHCb detector. The TED is currently closed, and so absorbed the proton beam before it could enter the LHC. However many muons were produced during the absorption process, and these muons passed through the TED and traversed the LHCb detector.

    This “beam dump” experiment therefore created an excellent opportunity for LHCb physicists and engineers to commission the LHCb detector and data acquisition system. The collected data are also useful for detector studies and alignment purposes (i.e. determining the relative geometrical locations of the different sub-detectors with respect to each other).

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    The image shows the shift leader, run coordinator, spokesperson and sub-detector experts in front of the LHCb data acquisition computer screens.

    LHCb took its last collision data on 14th February 2013. The two year Long Shutdown 1 (LS1) period that followed has been used for an extensive program of consolidation and maintenance (see 24 January 2014 “underground” news). Collisions are expected to resume again in Spring 2015.

    CERN LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC at CERN

    See the full article, with video, here.

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  • richardmitnick 3:00 pm on November 22, 2014 Permalink | Reply
    Tags: , , , , , Particle Physics,   

    From Triumf: “LHCb Experiment Confirms TRIUMF Prediction” 

    On Wednesday, November 19th, the LHCb collaboration at CERN’s Large Hadron Collider (LHC) announced the discovery of two new particles in the baryon family. The particles, known as the Xi_b’- and Xi_b*-, were predicted to exist by the quark model but had never been seen before.

    CERN LHCb New
    LHCb at CERN

    Randy Lewis, York University, and Richard Woloshyn (photographed), TRIUMF, submitted a paper together in 2009, “Bottom baryons from a dynamical lattice QCD simulation,” in which the masses of Xi_b’- and Xi_b* were predicted. This paper, among the eight theoretical papers cited in the LHCb collaboration report submitted to the Physical Review Letters, offered the LHCb researchers a light in the path of discovery.

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    Richard Woloshyn

    “Theoretical and experimental physics complement each other in an important way,” said Petr Navratil, Head of Theory Department at TRIUMF. “Richard’s work illustrates how theoretical predictions motivate experimental efforts. Experimental results then provide feedback to improve the theoretical understanding.”

    The new particles are baryons made from three quarks bound together by the strong force. The types of quarks are different, though: the new Xib particles both contain one beauty (b), one strange (s), and one down (d) quark. Thanks to the heavyweight b quarks, the baryons are more than six times as massive as the proton. But the particles are more than just the sum of their parts: their mass also depends on how they are configured. Each of the quarks has an attribute called “spin“. In the Xi_b’- state, the spins of the two lighter quarks point in opposite directions, whereas in the Xi_b*- state they are aligned. This difference makes the Xi_b*- a little heavier.

    “Nature was kind and gave us two particles for the price of one,” said
    Matthew Charles of the CNRS’s LPNHE laboratory at Paris VI University.

    “The Xi_b’- is very close in mass to the sum of its decay products: if it had been just a little lighter, we wouldn’t have seen it at all using the decay signature that we were looking for.”

    “This is a very exciting result. Thanks to LHCb’s excellent hadron identification, which is unique among the LHC experiments, we were able to separate a very clean and strong signal from the background,” said Steven Blusk from Syracuse University in New York. “It demonstrates once again the sensitivity and how precise the LHCb detector is.”

    “I am happy that LHCb cites our work and that it appears on the broader stage, ” said Richard Woloshyn, “It shows the work we do here at TRIUMF and in Canada is important.”

    As well as the masses of these particles, the LHCb team studied their relative production rates, their widths – a measure of how unstable they are – and other details of their decays. The results match up with predictions based on the theory of Quantum Chromodynamics (QCD). QCD is part of the Standard Model of particle physics, the theory that describes the fundamental particles of matter, how they interact and the forces between them.

    sm
    The Standard Model of elementary particles, with the three generations of matter, gauge bosons in the fourth column, and the Higgs boson in the fifth.

    “Our approach was based directly on QCD. These results give us confidence and show that the theory is adequate to deal with any measurement and to predict the outcomes of experiments,” said Richard.

    “This success is a reminder of TRIUMF’s leadership role in theoretical physics. Richard has been using the computational method called lattice QCD to make important contributions for many years, and I am one of several people who learned lattice QCD by spending time at TRIUMF with Richard,” said Randy Lewis.

    Richard admits that when he first saw the InterActions news release he did not expect it to be related to one of his theoretical ‘discoveries’ and set it aside to read later. It wasn’t until he saw the CBC headline, “New subatomic particles predicted by Canadians found at CERN” that he knew of his part in the discovery.

    See the full article here..

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    World Class Science at Triumf Lab, British Columbia, Canada
    Canada’s national laboratory for particle and nuclear physics
    Member Universities:
    University of Alberta, University of British Columbia, Carleton University, University of Guelph, University of Manitoba, Université de Montréal, Simon Fraser University,
    Queen’s University, University of Toronto, University of Victoria, York University. Not too shabby, eh?

    Associate Members:
    University of Calgary, McMaster University, University of Northern British Columbia, University of Regina, Saint Mary’s University, University of Winnipeg, How bad is that !!

     
  • richardmitnick 12:27 pm on November 20, 2014 Permalink | Reply
    Tags: , , , , , Particle Physics   

    From CERN: “CERN makes public first data of LHC experiments” 

    CERN New Masthead

    20 Nov 2014
    Cian O’Luanaigh

    CERN today launched its Open Data Portal where data from real collision events, produced by experiments at the Large Hadron Collider (LHC) will for the first time be made openly available to all. It is expected that these data will be of high value for the research community, and also be used for education purposes.

    CERN LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC at CERN

    cern

    “Launching the CERN Open Data Portal is an important step for our Organization. Data from the LHC programme are among the most precious assets of the LHC experiments, that today we start sharing openly with the world. We hope these open data will support and inspire the global research community, including students and citizen scientists,” says CERN Director-General Rolf Heuer.

    The principle of openness is enshrined in CERN’s founding Convention, and all LHC publications have been published Open Access, free for all to read and re-use. Widening the scope, the LHC collaborations recently approved Open Data policies and will release collision data over the coming years.

    The first high-level and analysable collision data openly released come from the CMS experiment and were originally collected in 2010 during the first LHC run. This data set is now publicly available on the CERN Open Data Portal. Open source software to read and analyse the data is also available, together with the corresponding documentation. The CMS collaboration is committed to releasing its data three years after collection, after they have been thoroughly studied by the collaboration.

    CERN CMS New
    CMS

    “This is all new and we are curious to see how the data will be re-used,” says CMS data preservation coordinator Kati Lassila-Perini. “We’ve prepared tools and examples of different levels of complexity from simplified analysis to ready-to-use online applications. We hope these examples will stimulate the creativity of external users.”

    In parallel, the CERN Open Data Portal gives access to additional event data sets from the ALICE, ATLAS, CMS and LHCb collaborations, which have been specifically prepared for educational purposes, such as the international masterclasses in particle physics benefiting over ten thousand high-school students every year. These resources are accompanied by visualisation tools.

    CERN ALICE New
    ALICE

    CERN ATLAS New
    ATLAS

    CERN LHCb New
    LHCb

    “Our own data policy foresees data preservation and its sharing. We have seen that students are fascinated by being able to analyse LHC data in the past and so, we are very happy to take the first steps and make available some selected data for education” says Silvia Amerio, data preservation coordinator of the LHCb experiment.

    “The development of this Open Data Portal represents a first milestone in our mission to serve our users in preserving and sharing their research materials. It will ensure that the data and tools can be accessed and used, now and in the future,” says Tim Smith of the CERN IT Department.

    All data on OpenData.cern.ch are shared under a Creative Commons CC0 public domain dedication; data and software are assigned unique DOI identifiers to make them citable in scientific articles; and software is released under open source licenses. The CERN Open Data Portal is built on the open-source Invenio Digital Library software, which powers other CERN Open Science tools and initiatives.

    See the full article here.

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  • richardmitnick 9:42 am on November 19, 2014 Permalink | Reply
    Tags: , , , , , Particle Physics   

    From LHCb at CERN: “LHCb experiment observes two new baryon particles never seen before” 

    CERN New Masthead

    19 Nov 2014
    No Writer Credit

    graph

    Geneva 19 November 2014. Today the collaboration for the LHCb experiment at CERN’s Large Hadron Collider announced the discovery of two new particles in the baryon family. The particles, known as the Xi_b’- and Xi_b*-, were predicted to exist by the quark model but had never been seen before. A related particle, the Xi_b*0, was found by the CMS experiment at CERN in 2012. The LHCb collaboration submitted a paper reporting the finding to Physical Review Letters.

    CERN LHCb New
    LHCb at CERN

    CERN LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC at CERN

    Like the well-known protons that the LHC accelerates, the new particles are baryons made from three quarks bound together by the strong force. The types of quarks are different, though: the new X_ib particles both contain one beauty (b), one strange (s), and one down (d) quark. Thanks to the heavyweight b quarks, they are more than six times as massive as the proton. But the particles are more than just the sum of their parts: their mass also depends on how they are configured. Each of the quarks has an attribute called “spin“. In the Xi_b’- state, the spins of the two lighter quarks point in opposite directions, whereas in the Xi_b*- state they are aligned. This difference makes the Xi_b*- a little heavier.

    “Nature was kind and gave us two particles for the price of one,” said Matthew Charles of the CNRS’s LPNHE laboratory at Paris VI University. “The Xi_b’- is very close in mass to the sum of its decay products: if it had been just a little lighter, we wouldn’t have seen it at all using the decay signature that we were looking for.”

    “This is a very exciting result. Thanks to LHCb’s excellent hadron identification, which is unique among the LHC experiments, we were able to separate a very clean and strong signal from the background,” said Steven Blusk from Syracuse University in New York. “It demonstrates once again the sensitivity and how precise the LHCb detector is.”

    As well as the masses of these particles, the research team studied their relative production rates, their widths – a measure of how unstable they are – and other details of their decays. The results match up with predictions based on the theory of Quantum Chromodynamics (QCD).

    QCD is part of the Standard Model of particle physics, the theory that describes the fundamental particles of matter, how they interact and the forces between them. Testing QCD at high precision is a key to refine our understanding of quark dynamics, models of which are tremendously difficult to calculate.

    sm
    The Standard Model of elementary particles, with the three generations of matter, gauge bosons in the fourth column, and the Higgs boson in the fifth.

    “If we want to find new physics beyond the Standard Model, we need first to have a sharp picture,” said LHCb’s physics coordinator Patrick Koppenburg from Nikhef Institute in Amsterdam. “Such high precision studies will help us to differentiate between Standard Model effects and anything new or unexpected in the future.”

    The measurements were made with the data taken at the LHC during 2011-2012. The LHC is currently being prepared – after its first long shutdown – to operate at higher energies and with more intense beams. It is scheduled to restart by spring 2015.

    Further information

    Caption diagram : The mass difference spectrum: the LHCb result shows strong evidence of the existence of two new particles the Xi_b’- (first peak) and Xi_b*- (second peak), with the very high-level confidence of 10 sigma. The black points are the signal sample and the hatched red histogram is a control sample. The blue curve represents a model including the two new particles, fitted to the data. Delta_m is the difference between the mass of the Xi_b0 pi- pair and the sum of the individual masses of the Xi_b0 and pi-.. INSET: Detail of the Xi_b’- region plotted with a finer binning.

    Link to the paper on Arxiv: http://arxiv.org/abs/1411.4849
    More about the result on LHCb’s collaboration website: http://lhcb-public.web.cern.ch/lhcb-public/Welcome.html#StrBeaBa
    Observation of a new Xi_b*0 beauty particle, on CMS’ collaboration website: http://cms.web.cern.ch/news/observation-new-xib0-beauty-particle
    Footnote(s)

    1. CERN, the European Organization for Nuclear Research, is the world’s leading laboratory for particle physics. It has its headquarters in Geneva. At present, its Member States are Austria, Belgium, Bulgaria, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Israel, Italy, the Netherlands, Norway, Poland, Portugal, Slovakia, Spain, Sweden, Switzerland and the United Kingdom. Romania is a Candidate for Accession. Serbia is an Associate Member in the pre-stage to Membership. India, Japan, the Russian Federation, the United States of America, Turkey, the European Commission and UNESCO have Observer Status.

    See the full article here.
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  • richardmitnick 1:14 pm on November 18, 2014 Permalink | Reply
    Tags: , , Larry McLerran, Particle Physics,   

    From BNL: “New Matter, Mathematical Models & Larry McLerran” 

    Brookhaven Lab

    November 18, 2014
    Joe Gettler

    American Physical Society to Honor Brookhaven Lab Physicist Larry McLerran With Feshbach Prize

    lm
    Larry McLerran

    With mathematical models, and some very good company both young and old, Larry McLerran’s decades-long quest to make sense of the laws governing the Universe’s most basic building blocks of matter has taken him from the United States’ West Coast to its East, and even as far as the Hunan province in central China. McLerran earned a Ph.D. in physics nearly forty years ago and today he’s a senior scientist at the Department of Energy’s Brookhaven National Laboratory (BNL) and Theory Group leader for the RIKEN BNL Research Center (RBRC). Now, the American Physical Society (APS) will recognize McLerran for his pursuits, when he is presented with the APS’ Feshbach Prize for outstanding lifetime achievements in nuclear physics theory.

    The APS will present McLerran with its Feshbach Prize during the annual APS meeting in Baltimore, Maryland, in April 2015. McLerran was chosen to receive this honor “for his pioneering study of quantum chromodynamics at high energy density and laying the theoretical foundations of experimental ultrarelativistic heavy ion collisions. His work has been a crucial guide to experiments at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider, and he has mentored a generation of young theorists.”

    BNL RHIC
    RHIC at BNL

    CERN LHC Grand Tunnel
    LHC at CERN

    “Over the years, I’ve worked with computers, pencils, chalk, and—most importantly—talented colleagues to figure out why the Universe behaves the way it does,” McLerran said. “I’m honored that my colleagues in the American Physical Society are recognizing me with this Feshbach Prize.”

    What’s the [New] Matter?

    “From tiny, short-lived subatomic particles to mysterious dark energy, the matter of our Universe forms beautiful, complex systems with many simple patterns and rules we understand very little about. There are great opportunities for discovery.”
    — Larry McLerran

    As a theoretical physicist, McLerran uses—and develops—complex mathematical models to figure out and explain why the Universe works the way it does. In particular, he probes the Universe within the scope of the theory of quantum chromodynamics, which describes the “strong” interactions among subatomic quarks and gluons that are naturally confined in protons and neutrons.

    In the early ’80s, McLerran and his colleague Ben Svetitsky of Tel Aviv University in Israel used computers that were powerful at the time and massive quantities of randomly generated numbers to do the first Monte Carlo simulation for high-temperature quantum chromodynamics. Together, they found a transition when those naturally confined quarks and gluons become free, no longer held captive by the strong force in the larger protons and neutrons. McLerran was among the first to propose that quark-gluon plasma—a blend of unbound quarks and gluons—could be produced by colliding heavy ions with high energies. Experimentalists later confirmed this at the Relativistic Heavy Ion Collider at Brookhaven Lab, where they produced quark-gluon plasma from colliding gold ions, yet they were surprised to learn quark-gluon plasma was a free-flowing liquid, not a gas as most theorists predicted.

    Many of McLerran’s more recent contributions and achievements resulted from collaborations with his colleagues in the Physics Department’s Nuclear Theory Group—which aims to understand the fundamental structure of matter—and RBRC, a research center at Brookhaven Lab funded primarily by the Japanese RIKEN Laboratory for researchers to develop theoretical and computational physics, and to analyze data produced from particle collisions at RHIC.

    “Since coming to Brookhaven, Larry has helped build one of the best nuclear theory groups in the world. And as theory group leader for the RIKEN BNL Research Center, he has inspired and mentored a generation of outstanding nuclear theorists in the U.S. and abroad,” Nuclear Theory Group Leader Raju Venugopalan said. “In my view, Larry’s outsized creative achievements and tremendous impact make him a guaranteed ‘slam-dunk’ case for a lifetime achievement award like this APS Feshbach Prize.”

    Venugopalan and McLerran invented the idea of a kind of matter called “color glass condensate” that controls the limits of quantum chromodynamics at high energies. McLerran and Rob Pisarski of the Nuclear Theory Group and RBRC invented the concept of “quarkyonic matter,” which has properties of both free quarks and other confined particles called mesons and baryons. And with the Nuclear Theory Group’s Dmitri Kharzeev and postdoc Harmen Warringa, McLerran made a seminal contribution to a theory called the “chiral magnetic effect.”

    McLerran also worked with Alex Kovner of the University of Connecticut and Heribert Weigert at the University of Cape Town in South Africa to invent the theory for yet another new form of matter, called “glasma,” which makes the transition between the color glass condensate and quark-gluon plasma in collisions among strongly interacting particles. Today, McLerran is focused on determining the properties of glasma.

    “From tiny, short-lived subatomic particles to mysterious dark energy, the matter of our Universe forms beautiful, complex systems with many simple patterns and rules we understand very little about. There are great opportunities for discovery,” said McLerran.

    McLerran’s Major Milestones

    McLerran earned a Ph.D. in physics from the University of Washington in 1975. He worked as a research associate at the Massachusetts Institute of Technology from 1975 to 1978, and then at Stanford Linear Accelerator Center from 1978 until 1980. From 1980 to 1984, he was an assistant and associate professor at the University of Washington, and from 1984 to 1989 a scientist at Fermi National Accelerator Laboratory. He taught as a professor at the University of Minnesota from 1988 to 2000, while also serving as a member and director of its Theoretical Physics Institute.

    In 1999, McLerran arrived at Brookhaven Lab as a senior scientist and led the Nuclear Theory Group until 2004. He took on his current role as the Theory Group Leader for the RIKEN BNL Research Center in 2003.

    McLerran has received a number of awards during his career, including a Brookhaven Science and Technology Award in FY2007—one of the Laboratory’s most distinguished prizes awarded for the exceptional nature of an employee’s contributions as well as the level of difficulty and benefit for Brookhaven.

    McLerran is a fellow of the American Physical Society and a foreign member of the Finnish Academy of Arts and Sciences. He was an Alexander Sloan Foundation Fellow; awarded the Alexander Humboldt prize in 1988; received the Hans Jensen prize at the University of Heidelberg in 2009, where he is a Jensen Professor of Theoretical Physics; and granted an honorary Ph.D. from Central China Normal University in 2011. He is currently the university’s Liu Lian Shou Professor of Theoretical Physics.

    Brookhaven National Laboratory is supported by the Office of Science of the U.S. Department of Energy. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.. Now, the American Physical Society (APS) will recognize McLerran for his pursuits, when he is presented with the APS’ Feshbach Prize for outstanding lifetime achievements in nuclear physics theory.

    The APS will present McLerran with its Feshbach Prize during the annual APS meeting in Baltimore, Maryland, in April 2015. McLerran was chosen to receive this honor “for his pioneering study of quantum chromodynamics at high energy density and laying the theoretical foundations of experimental ultrarelativistic heavy ion collisions. His work has been a crucial guide to experiments at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider, and he has mentored a generation of young theorists.”

    “Over the years, I’ve worked with computers, pencils, chalk, and—most importantly—talented colleagues to figure out why the Universe behaves the way it does,” McLerran said. “I’m honored that my colleagues in the American Physical Society are recognizing me with this Feshbach Prize.”
    What’s the [New] Matter?

    “From tiny, short-lived subatomic particles to mysterious dark energy, the matter of our Universe forms beautiful, complex systems with many simple patterns and rules we understand very little about. There are great opportunities for discovery.”
    — Larry McLerran

    As a theoretical physicist, McLerran uses—and develops—complex mathematical models to figure out and explain why the Universe works the way it does. In particular, he probes the Universe within the scope of the theory of quantum chromodynamics, which describes the “strong” interactions among subatomic quarks and gluons that are naturally confined in protons and neutrons.

    In the early ’80s, McLerran and his colleague Ben Svetitsky of Tel Aviv University in Israel used computers that were powerful at the time and massive quantities of randomly generated numbers to do the first Monte Carlo simulation for high-temperature quantum chromodynamics. Together, they found a transition when those naturally confined quarks and gluons become free, no longer held captive by the strong force in the larger protons and neutrons. McLerran was among the first to propose that quark-gluon plasma—a blend of unbound quarks and gluons—could be produced by colliding heavy ions with high energies. Experimentalists later confirmed this at the Relativistic Heavy Ion Collider at Brookhaven Lab, where they produced quark-gluon plasma from colliding gold ions, yet they were surprised to learn quark-gluon plasma was a free-flowing liquid, not a gas as most theorists predicted.

    Many of McLerran’s more recent contributions and achievements resulted from collaborations with his colleagues in the Physics Department’s Nuclear Theory Group—which aims to understand the fundamental structure of matter—and RBRC, a research center at Brookhaven Lab funded primarily by the Japanese RIKEN Laboratory for researchers to develop theoretical and computational physics, and to analyze data produced from particle collisions at RHIC.

    “Since coming to Brookhaven, Larry has helped build one of the best nuclear theory groups in the world. And as theory group leader for the RIKEN BNL Research Center, he has inspired and mentored a generation of outstanding nuclear theorists in the U.S. and abroad,” Nuclear Theory Group Leader Raju Venugopalan said. “In my view, Larry’s outsized creative achievements and tremendous impact make him a guaranteed ‘slam-dunk’ case for a lifetime achievement award like this APS Feshbach Prize.”

    Venugopalan and McLerran invented the idea of a kind of matter called “color glass condensate” that controls the limits of quantum chromodynamics at high energies. McLerran and Rob Pisarski of the Nuclear Theory Group and RBRC invented the concept of “quarkyonic matter,” which has properties of both free quarks and other confined particles called mesons and baryons. And with the Nuclear Theory Group’s Dmitri Kharzeev and postdoc Harmen Warringa, McLerran made a seminal contribution to a theory called the “chiral magnetic effect.”

    McLerran also worked with Alex Kovner of the University of Connecticut and Heribert Weigert at the University of Cape Town in South Africa to invent the theory for yet another new form of matter, called “glasma,” which makes the transition between the color glass condensate and quark-gluon plasma in collisions among strongly interacting particles. Today, McLerran is focused on determining the properties of glasma.

    “From tiny, short-lived subatomic particles to mysterious dark energy, the matter of our Universe forms beautiful, complex systems with many simple patterns and rules we understand very little about. There are great opportunities for discovery,” said McLerran.

    McLerran’s Major Milestones

    McLerran earned a Ph.D. in physics from the University of Washington in 1975. He worked as a research associate at the Massachusetts Institute of Technology from 1975 to 1978, and then at Stanford Linear Accelerator Center from 1978 until 1980. From 1980 to 1984, he was an assistant and associate professor at the University of Washington, and from 1984 to 1989 a scientist at Fermi National Accelerator Laboratory. He taught as a professor at the University of Minnesota from 1988 to 2000, while also serving as a member and director of its Theoretical Physics Institute.

    In 1999, McLerran arrived at Brookhaven Lab as a senior scientist and led the Nuclear Theory Group until 2004. He took on his current role as the Theory Group Leader for the RIKEN BNL Research Center in 2003.

    McLerran has received a number of awards during his career, including a Brookhaven Science and Technology Award in FY2007—one of the Laboratory’s most distinguished prizes awarded for the exceptional nature of an employee’s contributions as well as the level of difficulty and benefit for Brookhaven.

    McLerran is a fellow of the American Physical Society and a foreign member of the Finnish Academy of Arts and Sciences. He was an Alexander Sloan Foundation Fellow; awarded the Alexander Humboldt prize in 1988; received the Hans Jensen prize at the University of Heidelberg in 2009, where he is a Jensen Professor of Theoretical Physics; and granted an honorary Ph.D. from Central China Normal University in 2011. He is currently the university’s Liu Lian Shou Professor of Theoretical Physics.

    Brookhaven National Laboratory is supported by the Office of Science of the U.S. Department of Energy. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

    See the full article here.

    BNL Campus

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    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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  • richardmitnick 10:20 am on November 14, 2014 Permalink | Reply
    Tags: , , , , , , Particle Physics   

    From FNAL- “Frontier Science Result: CMS Origin of the smallest masses” 


    Fermilab is an enduring source of strength for the US contribution to scientific research world wide.

    Friday, Nov. 14, 2014
    Jim Pivarski

    Since the discovery of the Higgs boson two years ago, about 80 analyses have helped to pin down its properties. Today, we know that it does not spin, that it is mirror-symmetric, and that it decays into pairs of W bosons, pairs of Z bosons, pairs of tau leptons, and pairs of photons (through a pair of short-lived top quarks). There are even weak hints at a fifth decay mode: decays into pairs of b quarks. All of these results are in agreement with expectations for a Standard Model Higgs boson, but they are still coarse measurements with significant uncertainties.

    sm
    The Standard Model of elementary particles, with the three generations of matter, gauge bosons in the fourth column, and the Higgs boson in the fifth.

    To say that this boson is a Standard Model Higgs is to say that it is exactly the particle that was predicted in 1964. That leaves a lot of room for surprises. Without interference from new phenomena, the rate that this boson decays into particle-antiparticle pairs would be proportional to the square of the mass of the particle-antiparticle pairs. The best way to check the proportionality of something is to look at it on an extreme range. Since the Higgs is believed to give mass to everything from 0.0005-GeV electrons to 173-GeV top quarks, there’s plenty of room to check.

    dots
    Muons (red) are 18 times lighter than tau leptons (blue), so we expect Higgs decays to muon pairs to be about 300 times less common than Higgs decays to tau pairs.

    The highest decay rates are easiest to detect, so only the heaviest particle-antiparticle pairs have been tested so far. The lightest particle-antiparticle decay that has been observed is Higgs to pairs of tau leptons, which are 1.8 GeV each. The next-lighter final state that could be observed is Higgs to pairs of muons, which are 0.1 GeV each. By the expected scaling, Higgs to muon pairs should be 300 times less common. However, muons are easy to detect and clearly identify, so they make a good target.

    Even if you combine all the LHC data collected so far, it would not be enough to see evidence of this decay mode. However, the LHC is scheduled to restart next spring at almost twice its former energy. Higher energy and more intense beams would produce more Higgs bosons, making a future detection of Higgs to muon pairs possible.

    CERN LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC at CERN

    To prepare for such a discovery and find potential problems early, CMS scientists searched for Higgs to muon pairs in the current data set. They didn’t find any, but they did establish that no more than 0.16 percent of Higgs bosons decay into muons, only a factor of 7 from the expected number, and then they used these results to project sensitivity in future LHC data. Incidentally, the Higgs boson is the first particle known to decay into tau lepton pairs much more (6.3 percent) than muon pairs (0.023 percent). All other particles decay into taus and muons almost equally.

    CERN CMS New
    CMS in the LHC at CERN

    They also searched for Higgs decays into electrons, the lighter cousin of muons and tau leptons. Since electrons are 200 times lighter than muons, Higgs to electron pairs is expected only 0.00000051 percent of the time. None were found, though an observation would been an exciting surprise!

    See the full article here.

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  • richardmitnick 3:06 pm on November 13, 2014 Permalink | Reply
    Tags: , , , , , Particle Physics   

    From FNAL- “Frontier Science Result: DZero Sharing the momentum” 


    Fermilab is an enduring source of strength for the US contribution to scientific research world wide.

    Thursday, Nov. 13, 2014
    Leo Bellantoni

    The parts inside of a proton are called, in a not terribly imaginative terminology, partons. The partons that we tend to think of first and foremost are quarks — two up quarks and a down quark in each proton — but there are other kinds of partons as well.

    Each parton in a moving proton carries some momentum, which is a fraction of the total momentum of the proton. Because the partons interact with each other constantly, the momentum of a parton keeps changing. So at any particular time, there is some probability that the down quark is carrying, say, half the momentum of the proton, and later it might be a quarter of the total momentum. The fraction is called x. When the down quark is carrying half the momentum of the proton, it has an x of 0.5. These probabilities are key ingredients in calculating what happens in a hadron collider and can only be deduced from experiment.

    olot
    This plot shows the probabilities of finding up and down quarks with different fractions of a proton’s momentum. The vertical axis is arbitrary and different for the two curves. No image credit.

    The figure shows plots of the probabilities of finding up or down quarks at particular values of x. The vertical scale is a little arbitrary, but that won’t matter for us. Notice how the curve for down quarks, in blue, peaks at the left, at low values of x. That means that at any instant, the down quark tends to have a relatively small fraction of the proton’s momentum. The up quark curve, in red, has a ledge, a sort of bump in the generally downward slope at x around 0.2 or so. That means that the chances of an up quark having more momentum than a down quark are really pretty good.

    When a proton with a higher-momentum up quark hits an antiproton with a lower-momentum down antiquark, then these two partons can form a W+ boson, and that W+ boson is headed in the direction of the higher momentum. In a collision of an up antiquark and a down quark, a W- boson can be created that tends to travel in the antiproton direction. Things get a little more complicated when a W+ boson decays to a positron or a W- decays to electrons, but the positron and electron directions still carry information about the x-values of the colliding quarks.

    So the curves in the figure can be measured — or measured better — by looking at events in the Tevatron where a W+ or W- is produced and decays into a positron or electron and measuring the difference, or asymmetry, in the final electron and positron directions.

    DZero has measured the asymmetry in electron and positron directions relative to the direction of the proton’s motion when it collides with antiprotons in the Tevatron. The result is the most precise measurement of this asymmetry to date and provides important information about the momentum of the partons of protons. That information is critical in predicting what happens in all sorts of collisions involving protons, such as those at neutrino and LHC experiments.

    See the full article here.

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