Fermilab plans for a future of discovery

January 26, 2012 | 10:58 am

The only laboratory in the United States dedicated entirely to particle physics recently released its plan for the next two decades.

According to the document:

The keys to Fermilab’s long-term future are two facilities that could be operating in the 2020s: the Long-Baseline Neutrino Experiment and Project X.

LBNE will take the next major step in the quest to measure and understand the properties of neutrinos and determine their connection to the observed excess of matter over antimatter in the universe.

The Project X accelerator complex will be unique in the world in its ability to simultaneously deliver high-intensity proton beams in different formats to multiple experimental areas. Project X experiments using neutrinos, muons, kaons and nuclei will provide new windows on phenomena not accessible at particle colliders, and will be essential to break through to a deeper understanding of nature and the origins of matter.

Fermilab has proposed building detectors for LBNE at Sanford Underground Laboratory in Lead, South Dakota. The laboratory hopes to construct Project X on its campus.

In the near future, Fermilab will upgrade its accelerator complex to double the intensity of its proton beams, which scientists use to create beams of other particles such as neutrinos.

Read the full document, “A Plan for Discovery.”

Kathryn Grim

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Scientists finish installation of 80-ton ‘particle thermometer’ at ALICE detector

January 24, 2012 | 8:50 am

Scientists on the ALICE experiment at the Large Hadron Collider just completed the installation of a crucial component for tracking high-energy particle jets. Without it, physicists would be lacking critical tools to select which events out of billions to store and analyze.

Engineers and physicists around the world worked intensively over five years to complete the electromagnetic calorimeter, or EMCal. The United States, supported by the Department of Energy’s Nuclear Physics Office, contributed 70 percent of the project costs. Scientists installed the last two pieces of the 80-ton device on Jan. 18.

The EMCal’s heft comes from its many sheets of lead absorbers, which it needs to stop particles coming from collisions in the detector in order to measure their energy. “The calorimeter measures the energy of individual photons and electrons,” said ALICE physicist Peter Jacobs. “It’s a sort of particle thermometer.”

The ALICE detector’s calorimeter was specifically designed to study the most complex collisions at the LHC, those created using beams of heavy ions. These collisions recreate big-bang-like conditions and produce events with many more particles than the Large Hadron Collider’s usual collisions using beams of protons.

CERN typically smashes lead ions together each November. These collisions produce a goopy mixture, known as the quark-gluon plasma, in the center of ALICE. Occasionally, a very energetic quark or gluon, called a jet, will also be created in the collision. When this happens, the QGP gets in its way, and that interaction is important for researchers seeking to understand material which first existed in the earliest moments of the universe. The EMCal allows ALICE to select and record the rare events containing such jets, and to measure their properties precisely.

A second arm of the EMCal will be added to ALICE during the long LHC shutdown in 2013.

The two pieces of the EMCal scientists installed this year were small; they add only about 10 percent to the calorimeter’s overall coverage, Jacobs said. However, all the small parts do add up — every new measurement gets us a little closer to the heart of the matter.

Symmetry caught up with researcher Peter Jacobs underground during the end of the installation.

Amy Dusto

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Cutting-edge accelerator design gets results 60 years later

January 20, 2012 | 11:33 am

At Daresbury Laboratory in England, a team of scientists recently completed the first successful runs on a new prototype that may change the way accelerators speed up particles. Its novel design, scientists said, is capable of energies beyond the reach of current cyclotrons, with acceleration rates exceeding those of the most powerful synchrotrons – all within a compact, cost-effective and operationally simple package.

Daresbury’s high-intensity proton accelerator, called EMMA, gains its technological edge through an accelerator concept nearly abandoned a half century ago.

The accelerator’s magnet configuration incorporates a fixed field, rather than a pulsed field like a cyclotron, but includes alternating gradients like a synchrotron. The first versions of these fixed-field alternating-gradient machines were invented independently in Japan, Russia and the U.S. in the early 1950s.

The U.S. FFAG came about through the Midwest Universities Research Association, a group of 15 universities dedicated to developing a machine capable of accelerating particles beyond a billion electron volts, or 1 GeV. This unique institution soon built the first FFAG prototypes, albeit low-energy models.

“It was an exceedingly clever group of people. They had lots of ideas,” said Alvin Tollestrup, a long-time Fermilab physicist who attended MURA’s FFAG workshop.

For nearly 10 years, the MURA team pushed for a high-energy, high-intensity FFAG accelerator. One of several designs the group developed included colliding beams that essentially doubled the collision energy. They submitted a number of their proposals for machines in the 10-20 GeV range to the Atomic Energy Commission. None were approved.

Meanwhile, the invention of the storage ring and cascaded synchrotrons significantly reduced the cost of high-energy accelerators. As a consequence, a 1963 report, chaired by Norman Ramsey, to the Atomic Energy Commission ranked the FFAG project lower in priority than the competing proposals for high-energy particle beams.

Under rising excitement over a new strong-focusing synchrotron design that could achieve 300 GeV, and in the heat of an increasingly contentious political climate, the new president, Lyndon B. Johnson, rejected the MURA proposal on the basis of the report. MURA then disbanded, with the scientists shifting to accelerator laboratories like Fermilab, Berkeley and Brookhaven.

Although the technological advances and heavy influence of the MURA team did in part lead to the construction of Fermilab in the Midwest, the FFAG fell into obscurity.

Decades later, in a 1997 UCLA workshop on muon colliders, Fermilab physicist Carol Johnstone, while collaborating with one of the original MURA physicists, Fred Mills, proposed a new type of FFAG, termed non-scaling.

The FFAGs of the ‘50s followed a strict scaling method for the magnetic field to confine and accelerate beam. In the quest for a rapid acceleration scheme for unstable particles began a project that would for the first time ever combine FFAG with a new non-scaling method of beam confinement that resulted in smaller, simpler magnets.

The U.K.’s drive for an affordable collider that would accelerate and collide heavy elementary particles called muons set the stage for the prototype to be built at Daresbury Laboratory by a volunteer team of international scientists. Applied to a muon collider, the new non-scaling FFAG design would rapidly accelerate and inject the short-lived muon particles into storage or a collision before they decayed away.

“Emma was a bandwagon effect. It attracted accelerator physicists from across the world,” Johnstone said. “It’s the new technology that attracts the best.”

This FFAG format has the potential to quickly reach energies higher than 1 GeV, though the EMMA electron prototype tested at a moderate 20 million electron volts. The success of the preliminary runs put to rest decades of skepticism over FFAG technology. At a time when laboratories are pushing for more high-intensity experiments, the new approach is piquing interest among investors.

“Now that EMMA works, it’s considered a breakthrough,” Johnstone said. “And it’s a proof of principle for industry, too.”

Eventually EMMA’s method could be applied to a broad spectrum of accelerators. In medicine, the lower cost, versatile design and higher performance would enhance and expand proton and ion cancer therapy. For nuclear power, this accelerator-based approach could generate energy more safely while reusing old waste stockpiles. Along with muon colliders, a more cost-efficient generation of accelerators would greatly enhance experiments requiring high-energy neutrino beams.

“It’s interesting, I think, that something that was cooked up and kicked around 50 years ago all of a sudden could become quite interesting,” said Alvin Tollestrup. “There’s a number of interesting ideas for accelerators that haven’t been explored yet that could really change the way we accelerate particles.”

The journal Nature Physics recently covered the science behind EMMA in detail. For more history on FFAG, MURA and Fermilab, read “Fermilab: Physics, the Frontier, and Megascience,” by Lillian Hoddeson, Adrienne Kolb and Catherine Westfall.

Brad Hooker

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The Tevatron’s enduring computing legacy

January 18, 2012 | 3:53 pm

This story appeared Dec. 21 in iSGTW.

This is the first part of a two-part series on the contribution Tevatron-related computing has made to the world of computing. This part begins in 1981, when the Tevatron was under construction, and brings us up to recent times. The second part will focus on the most recent years, and look ahead to future analysis.

Few laypeople think of computing innovation in connection with the Tevatron particle accelerator, which shut down earlier this year. Mention of the Tevatron inspires images of majestic machinery, or thoughts of immense energies and groundbreaking physics research, not circuit boards, hardware, networks, and software.

Yet over the course of more than three decades of planning and operation, a tremendous amount of computing innovation was necessary to keep the data flowing and physics results coming. In fact, computing continues to do its work. Although the proton and antiproton beams no longer brighten the Tevatron’s tunnel, physicists expect to be using computing to continue analyzing a vast quantity of collected data for several years to come.

When all that data is analyzed, when all the physics results are published, the Tevatron will leave behind an enduring legacy. Not just a physics legacy, but also a computing legacy.

In the beginning: The fixed-target experiments

1981. The first Indiana Jones movie is released. Ronald Reagan is the U.S. President. Prince Charles makes Diana a Princess. And the first personal computers are introduced by IBM, setting the stage for a burst of computing innovation.

Meanwhile, at the Fermi National Accelerator Laboratory in Batavia, Illinois, the Tevatron has been under development for two years. And in 1982, the Advanced Computer Program formed to confront key particle physics computing problems. ACP tried something new in high performance computing: building custom systems using commercial components, which were rapidly dropping in price thanks to the introduction of personal computers. For a fraction of the cost, the resulting 100-node system doubled the processing power of Fermilab’s contemporary mainframe-style supercomputers.

“The use of farms of parallel computers based upon commercially available processors is largely an invention of the ACP,” said Mark Fischler, a Fermilab researcher who was part of the ACP. “This is an innovation which laid the philosophical foundation for the rise of high throughput computing, which is an industry standard in our field.”

The Tevatron fixed-target program, in which protons were accelerated to record-setting speeds before striking a stationary target, launched in 1983 with five separate experiments. When ACP’s system went online in 1986, the experiments were able to rapidly work through an accumulated three years of data in a fraction of that time.

Entering the collider era: Protons and antiprotons and run one

1985. NSFNET (National Science Foundation Network), one of the precursors to the modern Internet, is launched. And the Tevatron’s CDF detector sees its first proton-antiproton collisions, although the Tevatron’s official collider run one won’t begin until 1992.

The experiment’s central computing architecture filtered incoming data by running Fortran-77 algorithms on ACP’s 32-bit processors. But for run one, they needed more powerful computing systems.

By that time, commercial workstation prices had dropped so low that networking them together was simply more cost-effective than a new ACP system. ACP had one more major contribution to make, however: the Cooperative Processes Software.

CPS divided a computational task into a set of processes and distributed them across a processor farm – a collection of networked workstations. Although the term “high throughput computing” was not coined until 1996, CPS fits the HTC mold. As with modern HTC, farms using CPS are not supercomputer replacements. They are designed to be cost-effective platforms for solving specific compute-intensive problems in which each byte of data read requires 500-2000 machine instructions.

CPS went into production-level use at Fermilab in 1989; by 1992 it was being used by nine Fermilab experiments as well as a number of other groups worldwide.

1992 was also the year that the Tevatron’s second detector experiment, DZero, saw its first collisions. DZero launched with 50 traditional compute nodes running in parallel, connected to the detector electronics; the nodes executed filtering software written in Fortran, E-Pascal, and C.

Gearing up for run two

1990. CERN’s Tim Berners-Lee launches the first publicly accessible World Wide Web server using his URL and HTML standards. One year later, Linus Torvalds releases Linux to several Usenet newsgroups. And both DZero and CDF begin planning for the Tevatron’s collider run two.

Between the end of collider run one in 1996 and the beginning of run two in 2001, the accelerator and detectors were scheduled for substantial upgrades. Physicists anticipated more particle collisions at higher energies, and multiple interactions that were difficult to analyze and untangle. That translated into managing and storing 20 times the data from run one, and a growing need for computing resources for data analysis.

Enter the Run Two Computing Project (R2CP), in which representatives from both experiments collaborated with Fermilab’s Computing Division to find common solutions in areas ranging from visualization and physics analysis software to data access and storage management.

R2CP officially launched in 1996. It was the early days of the dot com era. eBay had existed for a year, and Google was still under development. IBM’s Deep Blue defeated chess master Garry Kasparov. And Linux was well-established as a reliable open-source operating system. The stage is set for experiments to get wired and start transferring their irreplaceable data to storage via Ethernet.

“It was a big leap of faith that it could be done over the network rather than putting tapes in a car and driving them from one location to another on the site,” said Stephen Wolbers, head of the scientific computing facilities in Fermilab’s computing sector. He added ruefully, “It seems obvious now.”

The R2CP’s philosophy was to use commercial technologies wherever possible. In the realm of data storage and management, however, none of the existing commercial software met their needs. To fill the gap, teams within the R2CP created Enstore and the Sequential Access Model (SAM, which later stood for Sequential Access through Meta-data). Enstore interfaces with the data tapes stored in automated tape robots, while SAM provides distributed data access and flexible dataset history and management.

By the time the Tevatron’s run two began in 2001, DZero was using both Enstore and SAM, and by 2003, CDF was also up and running on both systems.

Linux comes into play

The R2CP’s PC Farm Project targeted the issue of computing power for data analysis. Between 1997 and 1998, the project team successfully ported CPS and CDF’s analysis software to Linux. To take the next step and deploy the system more widely for CDF, however, they needed their own version of Red Hat Enterprise Linux. Fermi Linux was born, offering improved security and a customized installer; CDF migrated to the PC Farm model in 1998.

Fermi Linux enjoyed limited adoption outside of Fermilab, until 2003, when Red Hat Enterprise Linux ceased to be free. The Fermi Linux team rebuilt Red Hat Enterprise Linux into the prototype of Scientific Linux, and formed partnerships with colleagues at CERN in Geneva, Switzerland, as well as a number of other institutions; Scientific Linux was designed for site customizations, so that in supporting it they also supported Scientific Linux Fermi and Scientific Linux CERN.

Today, Scientific Linux is ranked 16th among open source operating systems; the latest version was downloaded over 3.5 million times in the first month following its release. It is used at government laboratories, universities, and even corporations all over the world.

“When we started Scientific Linux, we didn’t anticipate such widespread success,” said Connie Sieh, a Fermilab researcher and one of the leads on the Scientific Linux project. “We’re proud, though, that our work allows researchers across so many fields of study to keep on doing their science.”

Grid computing takes over

As both CDF and DZero datasets grew, so did the need for computing power. Dedicated computing farms reconstructed data, and users analyzed it using separate computing systems.

“As we moved into run two, people realized that we just couldn’t scale the system up to larger sizes,” Wolbers said. “We realized that there was really an opportunity here to use the same computer farms that we were using for reconstructing data, for user analysis.”

Today, the concept of opportunistic computing is closely linked to grid computing. But in 1996 the term “grid computing” had yet to be coined. The Condor Project had been developing tools for opportunistic computing since 1988. In 1998, the first Globus Toolkit was released. Experimental grid infrastructures were popping up everywhere, and in 2003, Fermilab researchers, led by DZero, partnered with the US Particle Physics Data Grid, the UK’s GridPP, CDF, the Condor team, the Globus team, and others to create the Job and Information Management system, JIM. Combining JIM with SAM resulted in a grid-enabled version of SAM: SAMgrid.

“A pioneering idea of SAMGrid was to use the Condor Match-Making service as a decision making broker for routing of jobs, a concept that was later adopted by other grids,” said Fermilab-based DZero scientist Adam Lyon. “This is an example of the DZero experiment contributing to the development of the core Grid technologies.”

By April 2003, the SAMGrid prototype was running on six clusters across two continents, setting the stage for the transition to the Open Science Grid in 2006.

From the Tevatron to the LHC – and beyond

Throughout run two, researchers continued to improve the computing infrastructure for both experiments. A number of computing innovations emerged before the run ended in September 2011. Among these was CDF’s GlideCAF, a system that used the Condor glide-in system and Generic Connection Brokering to provide an avenue through which CDF could submit jobs to the Open Science Grid. GlideCAF served as the starting point for the subsequent development of a more generic glidein Work Management System. Today glideinWMS is used by a wide variety of research projects across diverse research disciplines.

Another notable contribution was the Frontier system, which was originally designed by CDF to distribute data from central databases to numerous clients around the world. Frontier is optimized for applications where there are large numbers of widely distributed clients that read the same data at about the same time. Today, Frontier is used by CMS and ATLAS at the LHC.

“By the time the Tevatron shut down, DZero was processing collision events in near real-time and CDF was not far behind,” said Patricia McBride, the head of scientific programs in Fermilab’s computing sector. “We’ve come a long way; a few decades ago the fixed-target experiments would wait months before they could conduct the most basic data analysis.”

One of the key outcomes of computing at the Tevatron was the expertise developed at Fermilab over the years. Today, the Fermilab computing sector has become a worldwide leader in scientific computing for particle physics, astrophysics, and other related fields. Some of the field’s top experts worked on computing for the Tevatron. Some of those experts have moved on to work elsewhere, while others remain at Fermilab where work continues on Tevatron data analysis, a variety of Fermilab experiments, and of course the LHC.

The accomplishments of the many contributors to Tevatron-related computing are noteworthy. But there is a larger picture here.

“Whether in the form of concepts, or software, over the years the Tevatron has exerted an undeniable influence on the field of scientific computing,” said Ruth Pordes, Fermilab’s head of grids and outreach. “We’re very proud of the computing legacy we’ve left behind for the broader world of science.”

Miriam Boon

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Calling young scientists: Google teams up with CERN and Fermilab for 2012 science fair

January 12, 2012 | 10:17 am

Submissions opened today for Google’s second annual science fair.

Last year’s winner earned a trip to CERN laboratory in Europe, among other things. This year not one, but two particle physics institutions will contribute to the fair. Engineer Steve Myers, director of accelerators and technology at CERN, and physicist Young-Kee Kim, deputy director of Fermilab, will each participate on the final judging panel. The grand prize winner will receive a trip to visit both labs.

Submissions open today; applications can be found here.

Google Science Fair is an international competition for students between the ages of 13 and 18. All entrants, who can submit individually or in a group of up to three students, must create online profiles about their projects through the fair’s website. Then, a panel of preliminary judges will select 15 finalists to attend the fair’s last round of judging in person at the Google headquarters in Mountain View, California. The public also gets a say – one entrant will win the “People’s Choice Award” based on online votes.

In Mountain View a panel of high-profile scientists and leaders, including Myers and Kim, will choose a winner to fill each age category: ages 13-14, 15-16, 17-18 and the grand winner.

Kim, for one, said she is looking forward to the event this summer. As a middle school student in South Korea, Kim came out first in a regional science competition. “I think winning this competition gave me a lot of confidence about myself, and this greatly helped me to pursue my career in particle physics,” she said.

Last year’s grand winner, Shree Bose, plans to cash in her visit to CERN this spring. The prize this year will be slightly different. First, the winner will visit Fermilab and meet with a scientist from the CMS experiment, which has a remote control center at that lab. Then that scientist will accompany the winner from the U.S. to Geneva, Switzerland, to tour CERN.

In addition to laboratory visits, all finalists take home a host of other prizes including a hefty college scholarship.

Last year Google allowed only entries in English. But in the 2012 fair, Google is allowing entrants to submit projects in 13 different languages. The competition is sure to be tough. In 2011, more than 10,000 students in 90 countries submitted more than 7,500 projects.

Scientific American is sponsoring a new Science in Action award for “a project that addresses a social, environmental or health issue to make a practical difference in the lives of a group or community.” Also new this year will be the selection of 90 regional finalists: 30 each from the Americas, Europe-Middle East-Africa and Asia Pacific.

CERN is joined by LEGO, Scientific American and National Geographic in sponsoring the science fair.

The entry window closes on April 1, 2012. For more information, see Google Science Fair.

To watch a video about last years’ winners’ visit to the White House, see below.

Amy Dusto

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Belle experiment makes exotic discovery

January 11, 2012 | 4:29 am

The Belle Experiment at KEK laboratory in Japan has discovered two unexpected new types of hadrons. Hadrons are composite particles made up of quarks, the smallest known components of matter.

These new particles are thought to contain at least four quarks, making them exotic hadrons — hadrons that do not fit the quark model originally developed in 1961.

The B Factory experiment at KEK previously discovered exotic hadrons containing charm quarks. With this new finding, the Belle experiment has identified the first of this type of exotic hadrons discovered to contain bottom quarks, the second-heaviest type of quarks among the six known types of quarks. The particles, termed Zb, contain both one bottom quark and one anti-bottom quark.

Read more in a press release from KEK laboratory.

Kathryn Grim

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Clearest picture yet of dark matter points the way to better understanding of dark energy

January 10, 2012 | 1:38 pm

Two teams of physicists at the U.S. Department of Energy’s Fermilab and Lawrence Berkeley National Laboratory have independently made the largest direct measurements of the invisible scaffolding of the universe, building maps of dark matter using new methods that, in turn, will remove key hurdles for understanding dark energy with ground-based telescopes.

The teams’ measurements look for tiny distortions in the images of distant galaxies, called “cosmic shear,” caused by the gravitational influence of massive, invisible dark matter structures in the foreground. Accurately mapping out these dark-matter structures and their evolution over time is likely to be the most sensitive of the few tools available to physicists in their ongoing effort to understand the mysterious space-stretching effects of dark energy.

Both teams depended upon extensive databases of cosmic images collected by the Sloan Digital Sky Survey, which were compiled in large part with the help of Berkeley Lab and Fermilab.

“These results are very encouraging for future large sky surveys. The images produced lead to a picture of the galaxies in the universe that is about six times fainter, or further back in time, than is available from single images,” says Huan Lin, a Fermilab physicist and member of the SDSS and the Dark Energy Survey.

Read the rest of the press release issued jointly by Fermi National Accelerator Laboratory and Lawrence Berkeley Lab.

Read more from Fermilab at Quantum Diaries.

Read more from Berkeley Lab below.

Read the rest of this entry »

Guest author

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J-PARC completes first successful test run after earthquake

January 5, 2012 | 10:32 am

Fermilab Today published this article today.

Editor’s note: For over 30 years, Japanese and American researchers have enjoyed collaborating under the U.S.-Japan Agreement on High-Energy Physics.

Ten months after the earthquake and tsunami that devastated northern Japan, the Japan Proton Accelerator Research Complex (J-PARC) completed the first full test run for their system.

On March 11, 2011, the complex was extensively damaged, halting experiments for the highly international collaboration. From water in the Linac area to displaced walls and roads, it was clear that a great deal of work was ahead. The J-PARC center team created a master recovery schedule in May of 2011. The team met every milestone on time.

The complex, built as a joint project between the Japan Atomic Energy Agency and the High Energy Accelerator Research Organization (also known as KEK) with heavy international cooperation, houses several diverse research facilities. Three accelerators produce a primary proton beam used in tandem with smaller, more specific beams in each facility, based on use. For example, the T2K research team studies neutrinos produced from the primary proton beam.

The J-PARC team produced the first beam from the Linac on Dec. 9, a huge step signaling their ability to take beams at increasing energies. Just two weeks later, on Dec. 26, a full test run of the beam production and extraction through the neutrino hall was successfully completed.

While there are still a number of repairs to make, and the beam power is not quite at what was achieved prior to the earthquake, the center team expects to open J-PARC to users by the end of January.

In a series of email updates detailing the continued improvements, Shoji Nagamiya, director of J-PARC, expressed his gratitude for the many well-wishes from around the world. As a major component of J-PARC’s mission, the international support was greatly appreciated.

Ashley WennersHerron

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LHC heads into new year with first particle discovery

January 3, 2012 | 9:18 am

The first new particle was seen at the Large Hadron Collider at CERN in Switzerland shortly before Christmas.

The ATLAS collaboration announced the discovery of the particle Chi-b (3P), which consists of a bottom quark and antiquark particle bound together by the strong force. This force holds all atomic nuclei together so understanding Chi-b (3P) could help physicists understand better how the tiniest components of matter hold together to form the basis of everything you see: planets, people, plants.

Theorists have long proposed the existence of the Chi-b (3P), but until now it was not observed at any experiments. The particle is slightly heavier than predicted, meaning the quark anti-quark pair are a little more loosely bound than expected.

“Normally, a new particle is discovered in one or at most two channels, and the first discovery is at the very edge of statistical significance. This time things are different: it’s seen in three different channels and the peak is unmistakable,” according to an email by Tom LeCompte, the physics coordinator for the ATLAS collaborator and a physicist at Argonne National Laboratory outside Chicago. “The outstanding LHC performance is responsible for this by delivering so many collisions in such a short time.”

The ATLAS collaboration consists of 3,000 physicists from 38 countries.

Chi-b (3P) particle belongs to the boson family of particles just as the sought-after Higgs boson does. While the Higgs boson is suspected of giving all particles mass, Chi-b (3P) could explain how the mass of various elementary particles join together to make more massive, complex structures.

The bound quark states that make up Chi-b (3P) are collectively called quarkonium, and are analogues of the hydrogen atom, with each new particle corresponding to a different energy level. As with the hydrogen atom, physicists can observe transitions between these states through emission of a photon, according to the ATLAS collaboration.

A publication has been submitted to Physical Review Letters.

Read the ATLAS white paper: “Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS”

Related coverage:

BBC News: LHC reports discovery of its first new particle
Wired: LHC discovers a new particle: the Chi-b (3P)

Popsci.com: LHC has discovered its first new particle

Science Daily: New Particle at LHC Discovered by ATLAS Experiment

Tona Kunz

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The twelve days of winter break: particle physics edition

December 22, 2011 | 9:00 am

As symmetry breaking closes down for its long winter’s nap, please enjoy (or at least put up with) a badly adapted holiday song and the chance to reflect on a fascinating year in particle physics:

The Twelve Days of Winter Break: Particle Physics Edition

On the first day of winter break, I saw in symmetry…
possible Higgs (but not discovery).

On the second day of winter break, I saw in symmetry…
faster-than-light neutrinos
and possible Higgs (but not discovery).

On the third day of winter break, I saw in symmetry…
top quark asymmetry
faster-than-light neutrinos
and possible Higgs (but not discovery).

On the fourth day of winter break, I saw in symmetry…
one launching shuttle
top quark asymmetry
faster-than-light neutrinos
and possible Higgs (but not discovery).

On the fifth day of winter break, I saw in symmetry…
10,000 Legos
one launching shuttle
top quark asymmetry
faster-than-light neutrinos
and possible Higgs (but not discovery).

On the sixth day of winter break, I saw in symmetry…
CDF a-bumping
10,000 Legos
one launching shuttle
top quark asymmetry
faster-than-light neutrinos
and possible Higgs with sigmas under three.

On the seventh day of winter break, I saw in symmetry…
CP violation
CDF a-bumping
10,000 Legos
one launching shuttle
top quark asymmetry
faster-than-light neutrinos
and possible Higgs (but not discovery).

On the eighth day of winter break, I saw in symmetry…
one Muppet a-meeping
CP violation
CDF a-bumping
10,000 Legos
one launching shuttle
top quark asymmetry
faster-than-light neutrinos
and possible Higgs (but not discovery).

On the ninth day of winter break, I saw in symmetry…
Tevatron retiring
one Muppet a-meeping
CP violation
CDF a-bumping
10,000 Legos
one launching shuttle
top quark asymmetry
faster-than-light neutrinos
and possible Higgs (but not discovery).

On the tenth day of winter break, I saw in symmetry…
six neutrinos oscillating
Tevatron retiring
one Muppet a-meeping
CP violation
CDF a-bumping
10,000 Legos
one launching shuttle
top quark asymmetry
faster-than-light neutrinos
and possible Higgs (but not discovery).

On the eleventh day of winter break, I saw in symmetry…
just-discovered baryons
six neutrinos oscillating
Tevatron retiring
one Muppet a-meeping
CP violation
CDF a-bumping
10,000 Legos
one launching shuttle
top quark asymmetry
faster-than-light neutrinos
and possible Higgs (but not discovery).

On the twelfth day of winter break, I saw in symmetry…
antimatter ATRAP-ing
just-discovered baryons
six neutrinos oscillating
Tevatron retiring
one Muppet a-meeping
CP violation
CDF a-bumping
10,000 Legos
one launching shuttle
top quark asymmetry
faster-than-light neutrinos
and a verdict on Higgs by 2013.

Happy holidays, everyone! See you next year!

Kathryn Grim

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