CERN Council opens the door to greater integration

June 21, 2010 | 11:56 am

This release was issued on June 18, 2010, by CERN.

At its 155th session [Friday], the CERN Council strongly congratulated the Laboratory on the excellent performance of the LHC since its start-up for physics on 30 March this year. Council also opened the door to greater integration in particle physics when it unanimously adopted the recommendations of a working group set up in 2008 to examine the role of the Organization in the light of increasing globalization in particle physics.

The key points agreed at today’s meeting are that:

- All states shall be eligible for Membership, irrespective of their geographical location;
- A new Associate Membership status is to be introduced to allow non-Member States to establish or intensify their institutional links with the Organization;
- Associate Membership shall also serve as the obligatory pre-stage to Membership;
- The existing Observer status will be phased out for States, but retained for International Organizations;
- International co-operation agreements and protocols will be retained.

Applications for Membership from Cyprus, Israel, Serbia, Slovenia and Turkey have already been received by the CERN Council, and are undergoing technical verification. At future meetings, Council will determine how to apply the new arrangements to these States.

“This is a milestone in CERN’s history and a giant leap for particle physics”, said Michel Spiro, President of the CERN Council. “It recognizes the increasing globalization of the field, and the important role played by CERN on the world stage.”

“Particle physics is becoming increasingly integrated at the global level,” said CERN Director General Rolf Heuer. “Today’s decision contributes to creating the conditions that will enable CERN to play a full role in any future facility wherever in the world it might be.”

In other business, Council recognized that further work is necessary on the Organization’s medium term plan, in order to maintain a vibrant research programme through a period of financial austerity, and endorsed CERN’s new Code of Conduct.

“CERN’s new code of conduct enshrines the core values of this Organization,” said Spiro, “integrity, commitment, professionalism, creativity and diversity – which taken together add up to excellence.”

Full details of the new Membership arrangements are available in Council document CERN/2918.

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MiniBooNE results suggest antineutrinos act differently

June 18, 2010 | 12:41 pm

A comparison of the energy spectrum for MiniBooNE electron neutrino (top) and antineutrino (bottom) candidates. The MiniBooNE experiment has found that antineutrinos, which should follow the same rules as neutrinos, might oscillate in a slightly different way. Data is shown in blue points and compared to expected backgrounds. Data is taken with 6.5x1020 (neutrino beam) and 5.7x1020 (antineutrino beam) protons delivered to the MiniBooNE target. Statistical errors are shown on the data points, while systematic uncertainties are plotted on the background.

Neutrinos, the ubiquitous daughters of the weak interaction, start their universe-traversing lives as one of three varieties: ν_e, ν_μ, or ν_τ. However, like ghosts with an identity crisis, these phantasmal particles find themselves constantly morphing from one variety to another, or oscillating, as they propagate on their long journeys.

Now the MiniBooNE experiment has found that antineutrinos, which should follow the same rules as neutrinos, might oscillate in a slightly different way. The results seem to favor a much-debated antineutrino result obtained by the Liquid Scintillator Neutrino Detector experiment in 1990.

The MiniBooNE experiment studies these oscillations by creating intense beams of muon neutrinos and antineutrinos, and directing them at an 800-ton sphere filled with mineral oil and located a half a kilometer away from the beam’s source. The vast majority of these particles pass through the detector unscathed; however, a few unlucky voyagers pass too close to a carbon nucleus. The neutrinos, or antineutrinos, interact with carbon nuclei, giving scientists a glimpse of the particles’ true identities.

MiniBooNE counts how many muon antineutrinos oscillate into electron antineutrinos over a relatively short distance. A 1990 result from the LSND experiment at Los Alamos, which used a beam of muon antineutrinos, reported electron antineutrinos appearing about 0.25 percent of the time. The result is difficult for scientists to reconcile in a world with only three active neutrinos.

Earlier this week, after nearly three years of running in antineutrino mode, MiniBooNE collaborators announced that they had obtained a result consistent with the findings from LSND. In fact, analyzing the data in the context of a standard two neutrino mixing model favors an LSND-like signal at a 99.4 percent confidence level. However, model-independent tests show there is still a three percent chance that background fluctutations could mimic the data. While this new result is intriguing, a confirmation of LSND will require more data.

Interpretations of the latest MiniBooNE results are complicated due to an apparent difference between the way neutrinos and antineutrinos behave. In a prior analysis based on four years of running with a beam of muon neutrinos, the MiniBooNE experiment did not observe significant evidence for muon neutrinos oscillating to electron neutrinos in the energy range expected under the simplest models for explaining the LSND result. However, an excess was observed at lower neutrino energies (below 475 MeV) at a 3 sigma significance that remains unexplained.

Interestingly, the MINOS results announced earlier this week also raises the question as to whether neutrinos and antineutrinos behave differently.

The MiniBooNE experiment continues to acquire data, and scientists on the project are hoping to nearly double the antineutrino statistics before the experiment finishes acquiring data within the next two years. Future experiments, such as MicroBooNE or BooNE, a proposal to build a second MiniBooNE detector at a near location, could help to shed more light on these results.

This story first appeared in Fermilab Today on June 18, 2010.

Rhianna Wisniewski

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Three nerds walk into a bar…

June 15, 2010 | 9:46 am

Forty-odd Chicagoans gathered in a bar on June 3, not to watch the Blackhawks in the Stanley Cup finals, but to hear Jason St. John talk about particle colliders, the Standard Model and how the Large Hadron Collider won’t be the end of us all.

His lecture was part of Chicago’s inaugural Nerd Nite, a monthly series of informal talks intended to educate and entertain the community’s “lay nerds,” as St. John describes them, while they kick back with beers and martinis.

It was a far cry from the Ben Stein chalk talk that many have in mind when picturing physics presentations.

“He totally turned that upside-down,” says attendee Maurice Ball of the Mechanical Support Department in the Accelerator Division at Fermilab.

“Not that many people know quantum field theory or how to calculate branching ratios … but it’s not that hard conceptually,” says St. John, who helped organize the event.

As it turns out, it made for great Nerd Nite material.

Inside the California Clipper, an old-fashioned lounge in Chicago’s Humboldt Park neighborhood, St. John, who works on the CMS experiment at the LHC, took the mic in front of a largely graduate-student crowd. His aim was to unpack a topic that, while attracting a good deal of hoopla, is little understood by the public: the subatomic realm. With as much humor as studied consideration, he examined the controversy that made the LHC a hot news item a year ago – its reputation in some circles as an instrument of the world’s annihilation.

Conceding that it isn’t clear how to calculate how often proton collisions will produce black holes – which is why there’s controversy in the first place, he says – St. John laid out the physical arguments against the likelihood of a doomsday scenario in a way that was accessible to people who may have been hearing the term Planck scale for the first time.

“It was stuff I’d heard a hundred times before, but he explained it in a way that made you go ‘Oh, okay!’” Ball says.

Halley Brown, a scientist working on the CDF experiment at Fermilab, agrees. “I think the audience was kind of excited to hear an explanation that they could understand,” she says.

After the black hole lesson, St. John moved on to the science of high-energy physics. A cartoon of a proton beam collision – a big hit with the audience – led to a lively lesson in proton structure, the four fundamental forces, the rules governing the interactions between particles and what matter is and isn’t.

“Then I could show them Feynman diagrams that looked like animals: penguin diagrams, and others that look like dogs,” St. John says.

“St. John can explain a very complicated topic to … regular ‘civilians’ and make it exciting, funny and intriguing,” Ball says, noting that St. John created an environment where people could just blurt out questions.

St. John’s talk anchored an evening of three lectures, the first entitled “Parasitic Birds, Sex, Lies, and Dinosaurs.” A second lecture about 19th century Shakers had audience members singing a hymn in chorus.

As for St. John’s presentation, “It made me proud to be a part of this whole high-energy thing,” Ball says.

Nerd Nite began in Boston in 2003 and has since spread to Austin, Washington D.C., New York City and San Francisco.

Check out the event’s Web page.

by Leah Hesla

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New measurements from Fermilab’s MINOS experiment suggest a difference in a key property of neutrinos and antineutrinos

June 14, 2010 | 12:24 pm

The oscillations of antineutrinos depend on two parameters: the square of the antineutrino mass difference, Δm2, and the antineutrino mixing angle, sin22θ (shown in red). MINOS has found Δm2 = 0.0034 ± 0.0004 eV2. The MINOS neutrino results are show in blue for comparison. Theorists expected the values for neutrinos and antineutrinos to be the same.

Scientists of the MINOS experiment at the Department of Energy’s Fermi National Accelerator laboratory today (June 14) announced the world’s most precise measurement to date of the parameters that govern antineutrino oscillations, the back-and-forth transformations of antineutrinos from one type to another. This result provides information about the difference in mass between different antineutrino types. The measurement showed an unexpected variance in the values for neutrinos and antineutrinos. This mass difference parameter, called Δm² (“delta m squared”), is smaller by approximately 40 percent for neutrinos than for antineutrinos.

However, there is a still a five percent probability that Δm² is actually the same for neutrinos and antineutrinos. With such a level of uncertainty, MINOS physicists need more data and analysis to know for certain if the variance is real.

Neutrinos and antineutrinos behave differently in many respects, but the MINOS results, presented today at the Neutrino 2010 conference in Athens, Greece, and in a seminar at Fermilab, are the first observation of a potential fundamental difference that established physical theory could not explain.

“Everything we know up to now about neutrinos would tell you that our measured mass difference parameters should be very similar for neutrinos and antineutrinos,” said MINOS co-spokesperson Rob Plunkett. “If this result holds up, it would signal a fundamentally new property of the neutrino-antineutrino system. The implications of this difference for the physics of the universe would be profound.”

The NUMI beam is capable of producing intense beams of either antineutrinos or neutrinos. This capability allowed the experimenters to measure the unexpected mass difference parameters. The measurement also relies on the unique characteristics of the MINOS detector, particularly its magnetic field, which allows the detector to separate the positively and negatively charged muons resulting from interactions of antineutrinos and neutrinos, respectively. MINOS scientists have also updated their measurement of the standard oscillation parameters for muon neutrinos, providing an extremely precise value of Δm2.

Muon antineutrinos are produced in a beam originating in Fermilab’s Main Injector. The antineutrinos’ extremely rare interactions with matter allow most of them to pass through the Earth unperturbed. A small number, however, interact in the MINOS detector, located 735 km away from Fermilab in Soudan, Minnesota. During their journey, which lasts 2.5 milliseconds, the particles oscillate in a process governed by a difference between their mass states.

“We do know that a difference of this size in the behavior of neutrinos and antineutrinos could not be explained by current theory,” said MINOS co-spokesperson Jenny Thomas. “While the neutrinos and antineutrinos do behave differently on their journey through the Earth, the Standard Model predicts the effect is immeasurably small in the MINOS experiment. Clearly, more antineutrino running is essential to clarify whether this effect is just due to a statistical fluctuation.”

The MINOS experiment involves more than 140 scientists, engineers, technical specialists and students from 30 institutions, including universities and national laboratories, in five countries: Brazil, Greece, Poland, the United Kingdom and the United States. Funding comes from: the Department of Energy and the National Science Foundation in the U.S., the Science and Technology Facilities Council in the U.K; the University of Minnesota in the U.S.; the University of Athens in Greece; and Brazil’s Foundation for Research Support of the State of São Paulo (FAPESP) and National Council of Scientific and Technological Development (CNPq).

Fermilab is a national laboratory funded by the Office of Science of the U.S. Department of Energy, operated under contract by Fermi Research Alliance, LLC.

View the press release

Rhianna Wisniewski

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Rewriting textbooks and remeasuring the particle data booklet at the LHC

June 14, 2010 | 6:07 am

A pi-zero particle decay, as seen by the ALICE detector at the LHC. Image credit ALICE Collaboration

Textbooks were being rewritten during last week’s Physics at LHC conference.

“I was sitting in the session, listening to the ALICE talk by Andrea Dainese from Padova on Wednesday morning, and suddenly I knew: I could replace all the textbook bubble-chamber pictures from the sixties in my lectures,” said DESY’s Thomas Naumann, a member of the ATLAS collaboration.

Naumann’s revelation was sparked by an image showing a neutral pion decaying into two photons that then convert into two electron-positron pairs in the the ALICE inner tracker. Generations of physicists have learned about the history and characteristics of neutral pions, also called pi zero particles, in their undergraduate classes and textbooks. Until now, the decay of a pi zero particles was always illustrated with a picture from a 1950s- or 1960s-era bubble chamber experiment.

Pi zeros aren’t rare; in fact their decays are responsible for most of the photons seen in the LHC detectors. They are used as standard candles to calibrate detectors, which is why every student of particle physics has to know them inside out.  They’re also one of the many known particles being rediscovered by particle physicists using the first LHC collision data.

Theorist Hitoshi Murayama's prediction for a page in the PDG in 2016.

The particle physicist’s bible, the booklet published by the Particle Data Group or PDG, played an important role at the Physics at LHC conference. It contains tables with all the possible data for all existing and hypothetical particles, such as their mass, charge, flavor, lifetime and decay modes. LHC physicists are rediscovering the known particle families from strange through charm, and bottom through (hopefully soon) top, and in a matter of weeks they have almost reached the statistical precision currently listed in the PDG for many measurements.

The known particles aren’t the only ones being reassessed; theoretical physicists are also hard at work refining their predictions about particles and their behavior. In his talk, theorist Hitoshi Murayama of Japan’s Institute for the Physics and Mathematics of the Universe showed his vision of what the PDG could look like in a few years. A slide from his talk—originally called ‘Theories of Beyond the Standard Model Physics’ but renamed “How stupid theorists are and Why LHC matters”—features a page from the PDG in 2016.

by Barbara Warmbein

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Drinking data from a fire hose at the LHC

June 11, 2010 | 1:21 pm

This article first appeared June 11 in Fermilab Today.

With 2 1/2 months of running the Large Hadron Collider’s CMS experiment under our belts, our mid-range goals have evolved. Initially we were happy to record any interactions at a collision energy of 7 trillion electron volts. However, it’s important to recall that the beam energy is only one of the important parameters in a particle collider. A second critical parameter is the brightness of the beams, and, in the first few weeks of running, the brightness of the beams was tiny. Under these circumstances, the number of collisions per second was quite modest, and we could record every collision that occurred.

The amount of beam delivered has increased enormously. In the month and a half (45 days) since beginning operations, the amount of beam delivered is more than 10,000 times what we saw on the first day.

However, the beam brightness has steadily increased over the past two and a half months. It currently takes a minute to see as many collisions as we used to see in a day. Very soon, the same number of collisions will take seconds. Those of us of a certain age might remember the old I Love Lucy episode in which she and Ethel wrap candy. It starts out easily, but the rate quickly increases until they can no longer handle it and chaos ensues. This is essentially the situation in which the CMS detector collaborators find themselves.

Of course, this was anticipated. Today’s thousands of collisions per second are a far cry from the designed 800,000,000 collisions per second. To cope with the deluge, CMS designed an extensive trigger system. As the torrent of collisions occurs in the center of the detector, carefully designed electronics inspect them all and select those that are most likely to include a discovery. The LHC is now delivering enough beam that we must utilize the trigger system to record only a portion of the collisions.

This is a unique time in the lifetime of an experiment. About every week, the amount of beam delivered by the LHC doubles. With our trigger electronics doing their job, we look forward to seeing our data set grow in leaps and bounds.

by Don Lincoln

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Scientists present first “bread-and-butter” results from LHC collisions

June 8, 2010 | 8:50 am

One slide from CMS spokesperson Guido Tonelli's presentation, showing a preview of the results to be presented by members of the CMS collaboration at "Physics at LHC."

It’s been just over two months since the first high-energy proton collisions took place in the Large Hadron Collider, and scientists from the LHC experiments have been working feverishly to analyze the data now pouring from their detectors. The results of these first analyses using real LHC data are being presented this week at the “Physics at LHC” conference. The conference, taking place at the DESY laboratory in Hamburg, Germany, is the first in this summer’s series of international particle physics conferences.

LHC scientists have not yet found the Higgs boson, nor any hints of supersymmetric particles; these discoveries require much more collision data than has yet been collected. But nevertheless there is excitement among the 270 conference participants, who have been waiting years–in some cases decades–for the first proton-proton collisions at the LHC. With these data, particle physicists are doing what they call “bread-and-butter” physics: rediscovering the Standard Model.

The Standard Model of particle physics is the best theory that physicists currently have to describe the building blocks of the universe. With the exception of the discovery of the Higgs boson, the model has been very precisely measured at other particle accelerators and can thus be used as a touchstone to see if the LHC detectors work properly. Physicists also repeat Standard Model measurements to verify that their simulated data correspond to real data. The simulated data, also known as Monte Carlo data, will play a critical role in future discoveries.

The spokespeople of all four major LHC experiments–ALICE, ATLAS, CMS and LHCb–kicked off the first day of the conference by presenting results from their experiments since the first low-energy collisions in November 2009. All four spokespeople reported that the detectors work exceptionally well, have been able to record most of the collisions provided by the LHC, and that the known Standard Model is emerging beautifully in all of them. The CMS collaboration, for example, has caught the J/ψ particle 1,230 times.

“In other experiments I suffered a lot and for a long time to reach this point,” recounted CMS spokesperson Guido Tonelli. “At the LHC we get there in a few weeks. Amazing.” Tonelli was similarly proud of the detector’s performance in a process that hunts for secondary decays of beauty quarks, called b tagging. “There were people who thought it would be years before sophisticated techniques like b tagging could be used.”

With their detector recording an uptime of 90 percent, and good agreement between Monte Carlo data and real collisions, the members of the ATLAS collaboration are also having fun rediscovering the Standard Model. ATLAS spokesperson Fabiola Gianotti pointed out that the production of W and Z bosons had been previously measured, “but never before in proton-proton collisions.” ATLAS has submitted a total of six million jobs to the Worldwide LHC Computing Grid, with a total of 45 billion events analyzed.

Just as happy with their new collision data is the LHCb collaboration. Because of its salami-like slices (rather than the onion-like layers of the other three major LHC experiments) LHCb could not use cosmic rays to check and align its subdetectors. Precise detector alignment is crucial for experiments that are measuring the decays and paths of fundamental particles, thus the first collisions were especially important for LHCb, said spokesperson Andrey Golutvin. Similarly, spokesperson Jurgen Schukraft reported that ALICE detector is now now aligned and “literally in good shape.”

Bread and butter have never tasted so sweet.

The rest of the week will bring more results from the LHC experiments, so stay tuned to Symmetry Breaking for an update, or view the conference agenda to watch recorded videos or view slides from previous presentations.

by Barbara Warmbein

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Could DZero result point to multiple Higgses?

June 4, 2010 | 3:53 pm

Tona Kunz

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Anticipating the first steps beyond the Standard Model

June 3, 2010 | 12:20 pm

The particle physics community has just entered a critical new era with the commissioning of the Large Hadron Collider. The LHC has broken through the energy frontier and the first results are beginning to come out. Ultimately, the LHC will let scientists probe the laws of physics in new ways and may potentially reveal mysterious new phenomena, indicating that our current understanding of nature is incomplete. Within the next year, the LHC could discover the first signatures of new particles, new symmetries or even extra dimensions of space-time. The data collected could solve outstanding puzzles in physics or reveal new mysteries.

Physicists’ knowledge of elementary particles is encapsulated in the Standard Model of particle physics, which currently describes almost everything we’ve seen. Yet there is compelling evidence that the Standard Model cannot be the complete description of nature. For example, despite all of its successes, the Standard Model describes only 20 percent of the mass of the Universe. Eighty percent of the mass is known as “dark matter,” which we have never directly observed and know next to nothing about.

Another mystery of the Standard Model is that it typically predicts that the masses of all particles are incredibly heavy. To get the observed particle masses, the parameters of the theory have to be carefully balanced—precise to one part in 10³²—in order to add up many large contributions and get a small answer. The probability that this occurs randomly is like the chances of winning the California lottery four times in a row! We’ve seen such absurd tunings before in theories, and they almost always indicate that some physical mechanism is causing the delicate balance of parameters. The LHC is designed to discover the cause of this fine tuning of the Standard Model parameters. Of course, we don’t know what mechanism solves this fine tuning problem, but numerous theories have been developed over the past 30 years.

Chief among these new theories is supersymmetry, a theory that doubles the number of particles of nature and changes their spin from being an integer to half-integer or vice-versa. For instance, the gluon is a Standard Model particle that mediates the strong nuclear force and has spin of one. The gluon’s superpartner is the gluino which has spin of one half. Supersymmetric theories also include a natural particle that could be the dark matter of the universe and is typically the superpartner of the photon, sometimes called the photino. If real, the photino would be nearly invisible and stable. Photinos could pervade the Universe, with 1000 photinos passing through a person every second.

The LHC is currently running with an energy of 7000 GeV, only half of its design energy. However, this is still more than 3.5 times as energetic as the Tevatron at Fermilab. Pushing the energy frontier will suddenly enable the production of new particles that were previously hidden and, even with a modest amount of data, discoveries are possible. In the SLAC theory group, some of our work is to help estimate how effective the first year of the LHC will be at discovering new particles such as the gluino.

The gluino is one of the most spectacular particles that could be produced at the LHC. Gluinos can be produced in pairs when two gluons from the LHC’s colliding protons interact. After the gluinos are produced, most theories of supersymmetry predict that they will decay in a fleeting moment—10^-24 seconds—producing quarks and a photino. The photinos will just fly out of the LHC undetected, but their presence can be inferred by determining that energy is missing in the aftermath of the collision. The quarks are expected to produce a spray of strongly interacting particles as they leave the interaction region and can be reconstructed as “jets.” Therefore, the signature of gluino production at the LHC would be anomalous events with multiple jets and missing energy.

The primary challenge in discovering the gluino is to avoid mistaking something in the Standard Model for the gluino and at the same time ensure we aren’t dismissing gluinos as unusual properties of the Standard Model. Discovering new particles is a challenge that will require close collaboration between experimentalists and theorists in the high energy physics community. Our preliminary studies indicate that this next year holds amazing promise. To set the stage, with data from the past 10 years of running of the Tevatron, physicists have been able to push the discovery potential for gluinos from masses of 280 GeV up to 440 GeV. The data from the next year of LHC running will be enough to discover gluinos with masses of up to 800 GeV. We’re studying other theories that have similar signatures to gluinos and we’ve found that the LHC doubles their discovery potential. All this indicates that in the next year the LHC will rewrite what we know about the physics that takes us beyond the Standard Model of particle physics.

by Eder Izaguirre and Jay Wacker

This story first appeared in SLAC Today on June 3, 2010.

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Listening to the sound of science

June 1, 2010 | 4:27 pm

Ever wondered what you would hear if you could shrink to the size of a proton, squeeze into the Large Hadron Collider beam pipe, and listen to particles colliding? Would there be sounds, noises, maybe even music? That’s what Lily Asquith, ATLAS scientist and head of the LHCsound project, believes.

Asquith started thinking about an “audio event display” while chatting with some musician friends. “I was trying to make the noises I hear in my mind’s ear when I think of different particles moving through the detector,” she recalls. The project gradually took shape while Asquith finished her Ph.D. dissertation at University College London on the search for a low mass Higgs boson. In January, Asquith was awarded a grant from the UK’s Science and Technology Facilities Council for the sonification of ATLAS data, and she’s now leading a small team of two musicians/programmers, Archer Endrich and Richard Dobson from the Composer’s Desktop Project (CDP), and one illustrator, Toya Walker. The core development team is flanked by Ed Chocolate, DJ and producer, and Sir Eddie Real, percussionist, who are starting to incorporate sonified ATLAS data into their live performances.

Sonification is a technique that turns data into sounds while retaining all the original information contained in the data. A simple example is the beeping sound of a car parking sensor: the frequency of the beeps is related to the distance between your car and the obstacle, so that the closer you get, the higher the frequency. Sonification is also used in helping blind people to see, predicting earthquakes and identifying micrometeoroids impacting the Voyager II spacecraft.

The challenge for LHCsound is to find a coherent framework to map into sound the wide variety of abstract processes and variables involved in LHC experiments, such as the distribution in space and time of the particles emerging from a collision, the evolution of particles traveling through and interacting with matter, or even Feynman diagrams. A typical working session for the team includes a lively exchange of ideas (as well as computer programs and sound files) between the physicist and the musicians; whenever they are at a loss for words, diagram-drawing and strange vocalizations come into play.

“I bombard Dobson with crazy ideas for things like deconstructing a jet [of particles],” explains Asquith, “and he somehow understands what I am wittering on about and tells me what he needs to make the sound. Then I hack up bits of ATLAS software, stick them together and run over data to produce files of the format he needs.”

While Dobson created software to transform ATLAS data directly into sounds, Archer worked on converting these data in a format that can be used by the CDP software and thus be available for composers. Just three columns of numbers extracted by Asquith from the ATLAS reconstruction program gave birth to a wealth of sonifications of the quark jets generated from a decaying Higgs boson, with sound bites up to 90 seconds long.

The LHCsound website’s artwork is inspired by a similar brainstorming between Asquith and Walker, who discuss basic concepts like what makes particles different from one another. One discussion about the philosophical implications of finding the Higgs boson led to a portrait of the elusive particle as the Golden Snitch from the Harry Potter books.

Asquith is convinced that sonification could be useful for physics analyses. Our hearing system is a sophisticated neural network, capable of extracting a wealth of information from the sounds we listen to, with amazing precision – just the qualities that physicists expect from their analysis software. So, although the project was born as an outreach and musical composition endeavor, it might turn out to also have an impact on particle physics research.

Physicists’ curiosity about what particles sound like isn’t confined to the LHC. Across the Atlantic, physicists Agnes Mocsy from the Pratt Institute in New York and Paul Sorenson from Brookhaven National Laboratory teamed up with Alex Doig, senior illustration major at the Pratt Institute for “The Sound of the Little Bang” project. The “little bang” is what some physicists call the collisions between heavy nuclei inside particle accelerators, since they reproduce the condition of matter as it existed only millionths of seconds after the Big Bang. Brookhaven’s Relativistic Heavy Ion Collider smashes gold ions at nearly the speed of light to produce a peculiar type of matter called quark-gluon plasma. The plasma behaves like a liquid, and therefore sound waves should be able to propagate into it. Mocsy and Sorenson analysed the available RHIC data and obtained the sound produced by the quark-gluon plasma as it expands and cools down. The group posted a YouTube video describing the project and accompanying the sound with animation.

Both the LHC and RHIC projects aim at bringing science closer to the public in an innovative way, through music. Music is also the medium chosen by musician and producer John Boswell for his “Symphony of Science” – a series of inspiring digital mashups featuring famous scientists and science communicators like Carl Sagan, Richard Feynman and Brian Greene. Audios and videos from television programs and interviews are sampled and mixed, voices are pitch corrected and Boswell’s original compositions are added as soundtracks. The first video has collected almost 4 million hits on YouTube since its release in Fall 2009, and four more have since been produced. With the wealth of sounds now becoming available via sonification projects, perhaps a future Symphony of Science video will feature sounds from real RHIC or LHC data!

– Manuela Cirilli

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