[New Symmetry Issue] OPERA Catches Fifth Tau Neutrino; LHC Physicists Preserve Native American Voices

A joint Fermilab/SLAC publication

june 2015dimensionsofparticlephysicssymmetry

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Table of contents

Breaking: OPERA catches fifth tau neutrino

Application: LHC physicists preserve Native American voices

Signal to background: Q&A: New director-general of KEK

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breaking

June 16, 2015

OPERA catches fifth tau neutrinoThe OPERA experiment’s study of tau neutrino appearance hasreached the level of “discovery.”By Kathryn Jepsen

Today the OPERA experiment in Italy announced a discovery related to the behavior ofneutrinos.

Light, rarely interacting particles called neutrinos come in three types, called “flavors”:electron, muon and tau. When an electron neutrino collides with a detector, it producesan electron; a muon neutrino produces a muon; and a tau neutrino produces a tau.

In 1998, the Super-Kamiokande experiment in Japan found the first solid evidencethat neutrinos do not stick with any one flavor; they oscillate, or switch back and forthbetween flavors.

The Super-Kamiokande experiment studied muon neutrinos coming from cosmic raysand found that they were not catching as many as they expected; some of the muonneutrinos seemed to disappear. Researchers think they were changing to a flavor that theSuper-Kamiokande experiment could not see.

So scientists built an experiment that could see. The OPERA detector at the ItalianNational Institute for Nuclear Physics at Gran Sasso was the first that could catch anoscillated tau neutrino.

Between 2006 and 2012, the OPERA detector studied a beam of muon neutrinosproduced about 450 miles away at CERN on the border of France and Switzerland.Traveling at almost the speed of light, the neutrinos had just enough time to changeflavors between their point of origin and the detector.

Neutrinos can pass through the entire planet without bumping into another particle,but if you send enough of them through a large, sensitive detector, you can catch a smallnumber of them per day.

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In 2010, the OPERA experiment announced that it had found its first candidate tauneutrino coming from the muon neutrino beam. In 2012, 2013 and 2014, it announced itssecond, third and fourth.

Now the OPERA experiment has announced its fifth tau neutrino, bringing the result tothe level of “discovery.” The probability that they would find five tau neutrinos in theirdata by chance is less than one in a million.

“The detection of a fifth tau neutrino is extremely important,” says spokespersonGiovanni De Lellis of INFN in Naples, in a press release issued today. “We can…definitely report the discovery of the appearance of tau neutrinos in a muon neutrinobeam.”

Scientists will continue to analyze the data in search of additional tau neutrinos.

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application

June 10, 2015

LHC physicists preserve NativeAmerican voicesPhysicists are using LHC detector technology to retrieve NativeAmerican music from old recordings.By Sarah Charley

Berkeley physicist Carl Haber listened in astonishment as the first notes of the 1950s hit“Goodnight Irene” played through his computer.

“It was one of those moments you remember your whole life,” Haber says.

The song came from an old record, but no needle traced its grooves. Haber wasn’tlistening to the record; he was listening to an image of the record, which then-postdocVitaliy Fadeyev had produced by scanning it with a high-powered microscope. A set ofmathematical algorithms then interpreted the trenches embossed on the record’s surfaceand translated them into sounds.

Haber and Fadeyev were neither preservationists nor audio experts. Rather, theywere, and still are, both particle physicists working on the ATLAS experiment, a cathedral-sized particle detector located on CERN’s Large Hadron Collider. Haber is at LawrenceBerkeley National Laboratory and Fadeyev is now at the University of California, SantaCruz. They specialize in designing the delicate silicon detectors that record the charge,trajectory and momentum of particles produced immediately after the high-energy protoncollisions.

In order to pick out particles like the Higgs boson from the cacophony of noise createdduring the high-energy collisions, the LHC detectors must be extremely precise—soprecise that the inner detectors can distinguish between two particles separated by thewidth of a human hair.

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To make these detectors, physicists use optical imaging to determine the shapes ofthe components. Then they apply mathematical algorithms to analyze the components’dimensions and specialized machinery to piece them together with the precision of a fewmicrometers.

“It is a very powerful technique,” Haber says, “and I was very interested in what otherapplications it could have.”

Haber got his answer in the early 2000s on one of his many trips between Berkeley,where they were assembling the ATLAS detectors, and Silicon Valley, where he waspurchasing detector materials and fabricating detector components.

“I was driving and my brain was swirling with all these thoughts of imaging, analyzingand processing,” Haber says. “I was thinking about its applications, when I heard aninterview on the radio with Mickey Hart.”

Mickey Hart, the legendary drummer from the Grateful Dead, is an ethnographer anda huge proponent of preserving the heritage of music. During this radio interview, Hartexplained that there are thousands of old recordings cataloging the music, language andculture of at-risk indigenous communities. But these recordings, Hart explained, arestored on archaic, sometimes warped or broken material.

“And I thought,” Haber says, “if you could take a recording and turn it into a picture,then you could extract the information by using these mathematical approaches we wereapplying to our physics research.”

Early ethnographers made sound recordings using a diaphragm attached to a needle.When the diaphragm felt a sound wave generated by a voice or instrument, it vibrated,much like a human eardrum. These vibrations moved the needle, which inscribed themotions into a soft, rotating, material—like wax or aluminum.

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Ethnographer Frances Densmore with Blackfoot chief, Mountain Chief, during a 1916phonograph recording session for the Bureau of American Ethnology.

Courtesy of: Wikimedia Commons

“Tens of thousands of these recordings are stored in the Library of Congress, theSmithsonian Institution, and numerous archives and collections worldwide, but many ofthem are old, fragile, and in some cases, completely unplayable,” Haber says.

He encouraged Fadeyev to help him test his idea.

Fadeyev used traditional two-dimensional imaging to create a digital high-resolutionmap of the surface of the recording “Goodnight Irene.” After this first successfulexperiment, Haber and Fadeyev wrote a paper and sent it to half a dozen archivecenters. Almost immediately, they received a response from the Library of Congress andwere invited to Washington, DC.

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After two days of detailed discussions, Haber and Fadeyev returned to Berkeley witha much better idea of what they needed to do to bring these old recordings back to life.Over the course of the next decade Haber worked with Berkeley engineer Earl Cornell tofurther develop the technology and use it to lift voices from figure like Alexander GrahamBell, Jack London and Janis Joplin from unplayable recordings.

This summer, Haber and Cornell are partnering with the UC Berkeley LinguisticsDepartment and the UC Berkeley Libraries to start the biggest project yet—scanning andextracting sound from the 2700 wax cylinders stored in the University of CaliforniaPhoebe Hearst Museum of Anthropology that document the culture, language and musicof dozens of Native American tribes from California.

“These cylinders contain precious cultural artifacts, and we hope this project will makethese songs and languages accessible in the communities they belong to,” says BerkeleyProfessor of Linguistics Andrew Garrett.

The wax cylinders Haber and his colleagues will be working with for this new projectpreserve sounds in grooves at varying depths. For these recordings, Haber uses aconfocal microscope, which plays with focus and depth-of-field to determine the depth ofthe groove as it curves around the cylinder.

Preservationists tried to extract the sounds from these wax cylinders in the 1970s byrecording them onto tapes. But that solution left a lot to be desired, according to Garrett.

“The existing transfers are very noisy, and it is often impossible to even tell there isspeech, let alone make out what is being said,” Garrett says. “We’re hoping that thesenew recordings will be of a high enough quality that a fluent speaker could actuallyunderstand what’s being said and that people can hear the songs well enough to learnthem and perform them.”

After this project, Berkeley librarian Erik Mitchell hopes to apply this technique to helppreserve other collections of grooved media.

“Preserving records is a huge deal in our field, and digitization is still an emergingfield,” Mitchell says. “It’s really exciting to be part of something that we can replicate withother special collections stored in libraries and museums around the word. It’s a greatopportunity and has a broad interdisciplinary impact.”

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signal to background

June 11, 2015

Q&A: New director-general of KEKMasanori Yamauchi started his three-year term as head of Japan’smajor center of particle physics research this spring.By Kathryn Jepsen

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Courtesy of: KEK

At a recent symposium about the proposed International Linear Collider, Symmetrychatted with Masanori Yamauchi, the new director-general of KEK, Japan’s high-energyaccelerator research organization. Yamauchi, who received his PhD in physics at theUniversity of Tokyo, has been at the laboratory for more than 30 years.

S: When did you first become interested in physics?

MY: A long time ago, as a high school student. I read a book on symmetry andasymmetry which impressed me a lot. At university, I chose to enter the physicsdepartment.

S:What was particle physics like when you were a student?

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MY: When I was a grad student, I was staying at Lawrence Berkeley laboratory anddoing experiments at SLAC laboratory. At the time, things were centralized in the US andEurope. Experiments in Japan were small. The nature of collaboration at the time wasdifferent.

S: How has it changed?

MY: It’s more international. KEK’s Belle experiment, which started in 1999, is truly aninternational collaboration. Almost half of its members are from abroad.

These days more than 20,000 scientists visit KEK every year from abroad to carry outan extensive research program at the accelerator facilities. This provides an extraordinaryopportunity, especially to young scientists.

Now we’re hoping to construct the ILC in Japan. Everyone is getting together todesign the ILC from scratch. Japan is not taking a strong lead; it’s an internationalcollaboration.

S: What have been some of the highlights of your career?

MY: I was a spokesperson for the Belle experiment. We confirmed theory of CPviolation proposed by [theorists] Makoto Kobayashi and Toshihide Maskawa [who wonthe Nobel Prize in Physics in 2008].

In the course of measurements, we observed many interesting things, including CPviolation [a violation in the symmetry between matter and antimatter] in B meson decays.This is still puzzling. We still don’t know how it happens. We need at least 10 times moredata to find out. That’s why we started the upgrade of KEKB [KEK’s particle accelerator].It’s called Super KEKB factory, including the upgrade of detector to Belle II.

S: What do you do in your free time?

MY: I used to swim a lot, two times a week. Since I became the director-general ofKEK, I have no time to swim. That’s my pity.

S: What did you do to prepare to become director-general?

MY: I had many chances to talk to the former director-general.

I know what I should do. For a big lab like KEK, it’s extremely important to keep agood relationship with the Japanese people, including people in government and atfunding agencies. We deeply recognize that their understanding and support areessential to our scientific research. I often talk to them.

Conversation as the representative of KEK is a lot different from dialog with physicists.I’m not used to it. I have to find appropriate words. Physicists are more likely to talk veryfrankly and fight.

S: What makes KEK unique?

MY: One thing is our diversity. We cover many fields of research.

In physics, besides confirming the Kobayashi-Maskawa theory, we discovered manyexotic compound particles and confirmed the discovery of neutrino oscillation. In materialand life science, we determined the structure of novel superconductors and protein-drugcomplexes. We also studied novel properties induced by hydrogen atoms, spins andelectrons in condensed matter.

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We have two physics facilities, KEK and J-PARC. Between them we cover flavorphysics, B and D meson decays, tau lepton decays, kaons, muons and neutrinos. Wehave a commitment to the ATLAS experiment [at the Large Hadron Collider].

S: What are your priorities for KEK?

MY: KEK's mission in the near future is to derive the best scientific outcomes fromongoing research programs, and to open a firm route to future programs.

The most important thing is the construction of the Super KEKB factory [an upgrade ofthe KEKB accelerator]. We expect to have the first beam early next year. It is extremelyimportant for us to finish the beam. We are going to carry out a neutrino, muon and kaonprogram.

As I said, KEK does more than particle physics research. It also has nuclear physicsand materials science and life science programs. We will promote them as well.

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