[new symmetry issue] april 2013.pdf

7/30/2019 [new symmetry issue] April 2013.pdf

1/49

A joint Fermilab/SLAC publication

apridimensions

of

particle

physics

symmetry

1


2/49

Table of contents

Application: Semiconductors

Explain it in 60 seconds: Spin

Application: How particle physics improves your life

Day in the life: Programmed for success

Gallery: Cosmic open house draws curious crowd

Breaking: NOvA neutrino detector sees first particles

Breaking: BESIII collaboration catches new particle

Breaking: OPERA snags third tau neutrino

Breaking: Planck reveals new insight into universe

Breaking: One step closer to the Higgs boson

Breaking: LHCb studies particle tipping the matter-antimatter scales

Breaking: Higgs-like particle still looking like the Higgs

Signal to background: Astronomers give Dark Energy Camera rave reviews

Signal to background: Great minds lauded at physics prize ceremony

Signal to background: Meet 63 women in STEM, and counting

Signal to background: Research with flair at FameLab 2013

Signal to background: A different spin

Signal to background: Linear collider focus gets down to size

2


3/49

application

April 02, 2013

SemiconductorsAccelerator-powered ion implantation proves key to advances inintegrated circuits.By Glenn Roberts Jr.

Particle accelerators earned an important place on the semiconductor assembly linedecades ago, and today their role in silicon wafer manufacturing processes continues togrow in complexity and scope.

As a silicon wafer makes its way down the assembly line, it may pass through dozensof particle beams produced by accelerators in a process known as ion implantation. Bornout of the national labs, this process embeds fast-moving particles in the wafer at specificlocations, depths and concentrations, permanently changing the semiconductor'selectrical qualities by selectively creating an abundance of electrons or electronvacancies at specific locations.

These electron-rich or electron-depleted areas, in combination with other transistorcomponents affixed to the regions, work like rivers of charge to guide electrons around asemiconductor in precisely controlled ways.

Advances in ion implantation have helped manufacturers to pack more transitors intoan integrated circuit, revolutionizing computing speed and power and reducing room-sized machines to pocket-sized devices.

"Ion implantation is an absolutely necessary technology in the way we build devices,and its use has been growing," says Larry Larson, an engineering professor at TexasState University at San Marcos who previously worked for National Semiconductor, aSilicon Valley-based chip manufacturing firm acquired by Texas Instruments in 2011."Every time a factory is built, they need some number of ion-implantation machines in thefactory, and the number of machines per factory has grown over the years."

Today there are an estimated 12,000 ion-implantation accelerators operatingworldwide and an average of 300 new ones are purchased each year, with the lion's

3


4/49

share purchased by the semiconductor industry.

To meet manufacturing demands, the implanting processes become incrementallymore exacting and elaborate each year, with researchers fine-tuning the number ofparticle beams a single wafer encounters and the angle at which each beam hits thewafer. The speed of the implantation process is also ramping up to meet manufacturingdemand; today, the quickest implanters can process about 300 wafers an hour.

Alexander Wu Chao, a professor at SLAC National Accelerator Laboratory and editorof the journal Reviews of Accelerator Science and Technology, says that ion-implantationaccelerators are essential to todaysand tomorrowsadvanced electronics.

"They are becoming much more sophisticated and much more precise as required bymodern semiconductors," he says. While ion implantation is often used to treat flatsemiconductor surfaces, there are also applications that require implantation on the sidesof raised, gridded surfaces, which pose far more challenges in achieving uniform doping.

Accelerator advances in the semiconductor industry have contributed to theexponential growth of computing technology, Chao continues, saying that he expects "acontinuing evolution of accelerator technology to meet the increasing demands in the

years to come."

Above: A single silicon wafer, like the one seen here, is typically bombarded with ions of

several different elements. Boron, arsenic and phosphorous are among the elements

most commonly used in the semiconductor industry.

4


5/49

explain it in 60 seconds

March 07, 2013

SpinObjects as large as a planet or as small as a photon can have theproperty of spin. Spin is also the reason we can watch movies in 3D.By Jim Pivarski, Fermilab

Spin is the amount of rotation an object has, taking into account its mass and shape. Thisis also known as an objects angular momentum.

All objects have some amount of angular momentum. A spinning coin has a littleangular momentum; the moon orbiting the earth has a lot. Like energy, angularmomentum is a conserved quantity: The total amount is constant, though it can flow fromone object to another. When a spinning figure skater contracts her arms and rotatesfaster, her angular momentum is unchanged because a narrow object rotating quickly hasthe same angular momentum as a wide object rotating slowly.

Particles, as far as we know, are infinitesimal points of zero size. Yet they havemeasurable amounts of angular momentum. Does the concept of rotation even makesense for a featureless speck? Angular momentum seems to be a more foundationalconcept than rotation itself.

The angular momentum, or spin, of a single particle is restricted in strange ways. Itcan have only an certain values, and not all values are allowed for all particles. Electronsand quarks (particles of matter) can have a spin of 1/2 or +1/2; photons (particles oflight) can have a spin of 1 or +1; and Higgs bosons must have a spin of 0.

Though particle spins are tiny, they have an impact on our everyday world. The spinproperty of photons allows us to create 3D movies. A movie theater simultaneouslyprojects two images, one with positive-spin photons and the other with negative-spinphotons. One side of a pair of 3D glasses filters out the positive-spin photons, and theother filters out the negative-spin photons. We therefore see one image with each eye.Our brains combine them to create the illusion of depth.

It is a fortunate accident of biology that humans have as many eyes as photons have

5


6/49

spin states.

6


7/49

application

March 26, 2013

How particle physics improvesyour lifeFrom MRIs to shrink wrap, particle physics technology improves theworld we live in.

7


8/49

Diapers

Using particle accelerators, chemists were able for the first time to see the detailed wetstructure of the superabsorbent polymer material used in diapers. That enabled them toadjust and improve the formula for the superabsorbent polymers until they had the perfectmaterialthe one thats used in all modern-day diapers.

8
http://www.symmetrymagazine.org/sites/default/files/images/standard/application_diapers_0.png


9/49

Shrink wrap

If you buy a Butterball turkey, you have particle accelerators to thank for its freshness.For decades now the food industry has used particle accelerators to produce the sturdy,heat-shrinkable film that Butterball turkeysas well as fruits and vegetables, baked goods,board games and DVDscome wrapped in.

9
http://www.symmetrymagazine.org/sites/default/files/images/standard/application_shrinkwrap_0.png


10/49

Cargo scanning

More than 2 billion tons of cargo pass through ports and waterways annually in the UnitedStates. Many ports are now turning to high-energy X-rays generated by particleaccelerators to identify contraband and keep ports safe. These X-rays penetrate deeperand give screeners more detail about the nature of the cargo.

10
http://www.symmetrymagazine.org/sites/default/files/images/standard/application_cargo_0.png


11/49

MRI

The life-saving medical technology known as Magnetic Resonance Imaging makesdetailed images of soft tissue in the body. Unlike X-rays, MRIs can distinguish graymatter from white matter in the brain, cancerous tissue from noncancerous tissue, andmuscles from organs, as well as reveal blood flow and signs of stroke. Key aspects of thisimportant technology emerged from particle physics research.

11
http://www.symmetrymagazine.org/sites/default/files/images/standard/application_mri_0.png


12/49

Workforce development

Many of the people trained in particle physics move on to jobs in industry, medicine,computing or other fields where their skills are in high demand. You might find an experton particle detectors exploring for oil or an accelerator scientist working on cancertreatments.

12
http://www.symmetrymagazine.org/sites/default/files/images/standard/application_workforce_0.png


13/49

Heart valves

Physicists are improving the safety of artificial heart valves by designing a new materialbombarded with silver ions from a particle accelerator. The treated surface of the materialkeeps the body from identifying the valve as an invader and surrounding it with potentiallydangerous extra tissue.

13
http://www.symmetrymagazine.org/sites/default/files/images/standard/application_heart_0.png


14/49

Intense light for research

Circular particle accelerators bend the paths of speeding electrons, causing the electronsto emit light. This light is a powerful research tool with many applications. Dedicatedsynchrotron accelerators known as light sources allow scientists to control the intensityand wavelength of light for research thats led to better batteries, greener energy, newhigh-performance materials, more effective drug treatments and a deeper understandingof nature.

14
http://www.symmetrymagazine.org/sites/default/files/images/standard/application_light_0.png


15/49

Grid computing

The World Wide Web isnt the only computing advancement to come out of particlephysics. To deal with the computing demands of the LHC experiments, particle physicistshave created the world's largest Grid computing system, spanning more than 100institutions in 36 countries and pushing the boundaries of global networking anddistributed computing.

15
http://www.symmetrymagazine.org/sites/default/files/images/standard/application_grid_0.png


16/49

Furniture finish

For a quarter of a century, companies around the world used beams of electrons fromparticle accelerators to make scratch- and stain-resistant furniture. The surfaces of thesetreated desks, shelves and tables look like wood but are nearly impossible to scuff.

16
http://www.symmetrymagazine.org/sites/default/files/images/standard/application_finish_0.png


17/49

day in the life

March 19, 2013

Programmed for successFormer particle physicist John Mansour still creates analyticsolutionsthese days, for retail clients.By Heather Rock Woods

John Mansours professional life has zigged and zagged like a bright green line on anoscilloscope, always centered on a love of physics.

As a kid, I was always reading about space travel and astronomycouldn't getenough of it. So I pretty much knew I was going into physics from a very early age,Mansour says.

Now in his early 50s, he is vice president and leads the development team in theAdvanced Solutions Group of Nielsen in Schaumburg, Illinoisnot far from Fermilab,where he conducted his PhD thesis experiment.

When I was at Fermilab, 90 percent of my work was programming or buildinghardware, he says. At Nielsen, our group writes a variety of custom programs toprocess and analyze large amounts of data for the consumer packaged goods industry,mostly food and beverages. We get very challenging and interesting projects to work on,and the people I work with are smart and hardworking, very similar to Fermilab. So notmuch is really changed.

Mansour has made some adjustments over the years, however, including during hisgraduate studies at the University of Rochester, where he had intended to study optics.The first career turning point arrived when he crossed paths in the hall one day withUniversity of Rochester Physics Professor Tom Ferbel. He asked me if I wanted to workwith his team at Fermilab for the summer, Mansour says. Well after that summer, I washooked. I loved the work, the people and the environment.

Mansour joined Fermilabs E706, an experiment that observed the production ofphotons in the interactions of quarks and gluons. With Ferbel as his advisor, hemeasured a major source of experimental background noise for his thesis.

17


18/49

Fellow Rochester and E706 grad student Nikos Varelas became a close friend, andthe two still meet often to discuss physics news and life.

The experience John had in high-energy physics provided a very good backgroundto bridge the gap between statistical methodology, application development and analysisof business needs, says Varelas, now a physics professor at the University of Illinois atChicago. And although he left physics 18 years ago, he is still keeping up with thedevelopments and discoveries in the field.

Mansour scans articles on preprint and science sites and reads books to stay current,but claims, My physics is a bit rusty; Nikos shows a lot of patience.

Nonetheless, Mansour says that he continues to draw on many of the skills hedeveloped during his physics training. The switch to Nielsen in 1995, for example,required knowledge of Fortran, C and multivariate regressionso I was a good fit, hesays.

Its been a happy match for Nielsen and Mansour.

Today, Mansour says, a good understanding of the math and programming helps

bring ideas generated in our group to production. In addition, the ability to analyze andsolve problems is huge.

His group helps clients enhance their marketing and promotion strategies, which inturn can benefit consumers with better prices. The group also does pro bono projects;recently, they helped a nonprofit agency more efficiently distribute food where it was mostneeded.

Like his clients, Mansours colleagues welcome his physics-based capabilitiesaswell as his views on topics like the Higgs boson.

John approaches his job as a scientist, leveraging methods from many scientificfields, says Mitch Kriss, a Nielsen senior vice president of research and development. Ihave not found an analytical business problem that he was unable to solve.

18


19/49

gallery

March 29, 2013

Cosmic open house drawscurious crowdKids of all ages flocked to SLAC National Accelerator Laboratory tolearn about the universe and have fun doing it.By Lori Ann White

Last Sunday, 350 of the closest friends and neighbors of the Kavli Institute for ParticleAstrophysics and Cosmology streamed onto the SLAC campus to help celebrate theinstitutes 10th birthday.

Instead of gifts, the guests brought something better: curiosity and enthusiasm.

KIPAC's open house, meant to share the discoveries made during a decade ofresearch, included more "eyes-on" and "minds-on" activities than hands-on onesfittingfor an institute that focuses on finding new and better ways to learn about our universefrom the scant photons it sends our way.

Several KIPAC scientists were kicked out of their offices for the day and replaced bybooths. Favorite stops included a small, simple bubble chamber that drew a perpetualcrowd of visitors. Peering into the tank, guests saw the tracks of cosmic rays appear and

then fade away like particle ghosts. The Visualization Lab, where KIPAC scientistsscreened large-scale simulations of the birth of the universe and the behavior of darkmatter haloes in three dimensions, revealed the utter beauty of science. And the "makeyour own pulsar" booth drew kids of all ages: A lump of clay wrapped around two red LEDbulbs linked by a watch battery might not sound enticing, but spin it on the end of a stringand the resemblance to a pulsar becomes immediately apparent.

KIPAC science took center stage in auditorium-filling talks on topics including the two"darks" (matter and energy), black holes and the institute's current flagship project, theFermi Gamma-ray Space Telescope.

Researchers were also on hand to explain the cosmic microwave background,

19


20/49

gravitational lensing (including a "lens yourself" version of a photo booth), and thetaxonomy of galaxies. Guests could take advantage of the sunny spring weather to peerthrough solar telescopes set up on the lawn. Sadly, it was a "boring day for the Sun," asone of the KIPAC postdocs on duty admitted, with only a few prominences and a lone sunspot visible. They could also learn more about what the telescopes couldn't tell them atthe exhibit showcasing the Solar Dynamics Observatory, a project with significant KIPACinvolvement.

One booth, "The Physics of Star Trek," seemed particularly popular with the oldercrowd. Stubborn baby boomers argued for the feasibility of warp drives and transportersand made their preferences for time travel quite clear. But even though KIPAC studiesphysics, not fiction, they still packed their party with a sense of wonder.

Really, the only thing missing was the cake.

20


21/49

breaking

March 27, 2013

NOvA neutrino detector sees firstparticlesThe NOvA neutrino detector, currently under construction, hasalready begun to take data from cosmic rays.By Kathryn Jepsen

What will soon be the most powerful neutrino detector in the United States has begunrecording its first images of particles.

The NOvA detector is still under construction in Ash River, Minn. However, using itsfirst completed section, scientists have begun collecting data from cosmic raysparticlesproduced by a constant rain of atomic nuclei falling on the Earths atmosphere fromspace. The detector takes three-dimensional images of the particles' tracks as they passthrough it.

Its taken years of hard work and close collaboration among universities, nationallaboratories and private companies to get to this point, says Pier Oddone, director of theDepartment of Energys Fermi National Accelerator Laboratory. Fermilab manages theproject to construct the detector.

The active section of the detector is about 12 feet long, 15 feet wide and 20 feet tall.When complete, the full detector will measure more than 200 feet long, 50 feet wide and50 feet tall.

Ultimately, the scientists' goal is to discover properties of mysterious fundamentalparticles called neutrinos. Neutrinos are as abundant as cosmic rays in the atmosphere,but they have barely any mass and interact much more rarely with other matter. Many ofthe neutrinos around today are thought to have originated in the big bang.

The more we know about neutrinos, the more we know about the early universe andabout how our world works at its most basic level, says NOvA co-spokesperson GaryFeldman of Harvard University.

21


22/49

Later this year, Fermilab, outside of Chicago, will start sending a beam of neutrinos500 miles through the earth to the NOvA detector near the Canadian border.

When a neutrino interacts in the NOvA detector, the particles it produces leave trailsof light in their wake. The detector records these streams of light, enabling physicists toidentify the original neutrino and measure the amount of energy it had.

When cosmic rays pass through the NOvA detector, they leave straight tracks and

deposit well-known amounts of energy. They are great for calibration, says Mat Muether,a Fermilab post-doctoral researcher who has been working on the detector.

Everybody loves cosmic rays for this reason, Muether says. They are simple andabundant and a perfect tool for tuning up a new detector.

The detector at its current size catches more than 1000 cosmic rays per second.Naturally occurring neutrinos from cosmic rays, supernovae and the sun stream throughthe detector at the same time. But the flood of more visible cosmic-ray data makes itdifficult to pick them out.

Once the Fermilab neutrino beam starts, the NOvA detector will take data every 1.3

seconds to synchronize with the Fermilab accelerator. Inside this short time window, theburst of neutrinos from Fermilab will be much easier to spot.

This 3D image shows a cosmic-ray muon producing a large shower of energy as itpasses through the NOvA detector in Minnesota. Courtesy of: NOvA collaboration

Fermilab released a version of this text as apress release.

22
http://www.fnal.gov/pub/presspass/press_releases/2013/NOvA-20130328.htmlhttp://www.fnal.gov/pub/presspass/press_releases/2013/NOvA-20130328.htmlhttp://www.symmetrymagazine.org/sites/default/files/images/standard/3D-image-black-s.jpg


23/49

breaking

March 26, 2013

BESIII collaboration catches newparticleA new particle spotted at Chinas Beijing Electron Positron Colliderraises more questions than it answers.By Kelen Tuttle

The plot has thickened for scientists studying a recently discovered particle at the BeijingElectron Spectrometer. For the past three months, the BESIII collaboration has studiedthe Y(4260) particle, discovered in 2005, to try to understand why this anomalouscreature refuses to conform to scientists understanding of similar particles. Surprisingly,the first result from these studies is the observation another new, unexpected andmysterious particle named the Z_c(3900).

The Y(4260), originally discovered by the BaBar collaboration, is a bit of an odd duck.Other particles with similar characteristicscalled charmoniumare composed of acharm quark and an anti-charm quark held together by the strong force. Yet the Y(4260)doesnt seem to fit this model and its building blocks remain unclear.

In an attempt to better understand the Y(4260), researchers collided electrons andtheir antimatter counterparts, positrons, at the Beijing Electron Spectrometer using just

the right energy to produce more than 1000 observed Y(4260) decays. By seeing howthese Y(4260) particles decay into other particles, researchers seek to clarify theirinternal structure.

Yet, so far, what theyve seen is even more mysterious than the question they set outto answer. In addition to more common particles, the Y(4260) also decays into the newlydiscovered Z_c(3900) particle, which also does not fit into the charmonium box. Whilestandard charmonium particles are neutral, the Z_c(3900) is charged.

Both the Y(4260) and the Z_c(3900) appear to be members of a new class of particlescalled the XYZ mesons. Further studies will seek to reveal the building blocks of both the

Y(4260) and the Z_c(3900).

23


24/49

"We are very excited about this," says Yifang Wang, director of the Institute of HighEnergy Physics at Beijing, in a press release issued by the institute. "With our Beijingcollider, we can accumulate a lot more data that will permit more comprehensiveinvestigations of the nature of this unusual, electrically charged charmonium state. Whenall of these results are used as inputs to theory, we may begin to open the door toward afuller understanding of the XYZ particles discovered in recent years."

24
http://english.ihep.cas.cn/prs/ns/201303/t20130326_100230.htmlhttp://english.ihep.cas.cn/prs/ns/201303/t20130326_100230.html


25/49

breaking

March 26, 2013

OPERA snags third tau neutrinoFor the third time since the OPERA detector began receiving beamin 2006, the experiment has caught a muon neutrino oscillating intoa tau neutrino.By Kathryn Jepsen

For the third time ever, scientists have seen the particle transformation that explains themystery of the missing neutrinosparticles we expect to rain down from the Sun and

Earths atmosphere at higher rates than observed.

Neutrinos are light particles that come in three types, or flavors, each associated witha different subatomic particle: an electron, a muon or a tau. One of the biggest surprisesthat came with the discovery of neutrinos was that they could change from flavor to flavor.

Members of the OPERA experiment announced today the observation of a muonneutrino that had switched flavors to a tau neutrino. OPERA scientists, based at GranSasso National Laboratory in Italy, have caught this rare event only twice before, once in2010 and once in 2012.

The new observation is an important confirmation of the two previous observations,says Giovanni De Lellis, head of the international research team, in a statement releasedby INFN.

The OPERA experiment is a fast-moving, long-distance game of catch, with CERNlaboratory at the border of France and Switzerland pitching a concentrated beam ofneutrinos toward the 1,250-ton OPERA detector. The neutrino is a difficult ball to snag; itinteracts so rarely with matter that it can zip unflinchingly through an entire planet.

The OPERA experiment is the first neutrino experiment to examine a manmade beamof muon neutrinos in search of this type of oscillation. It will continue to take data for thenext two years.

25
http://www.infn.it/news/newsen.php?id=663http://www.infn.it/news/newsen.php?id=663


26/4926


27/49

breaking

March 21, 2013

Planck reveals new insight intouniverseThe first cosmology results from the Planck satellite reveal an olderuniverse populated with less dark energy and more matter thanexpected.By Kelen Tuttle

This morning, scientists on the Planck space mission released the most detailed map yetof the afterglow of the big bang. It reveals that our universe is about 100 million yearsolder, is expanding slower and contains less dark energy and more matterboth normaland darkthan previously thought.

The Planck map is the sharpest such map ever produced, says Paul Hertz, director ofastrophysics at NASA, which participated in the European Space Agency-led mission.Its as if weve gone from a standard television to a high-definition television.

The map shows the geography of the cosmic microwave background, the lightreleased as the first atoms formed when the universe was about 370,000 years old. Forthe past 15 months, Planck scanned the full visible sky, taking the most detailedmeasurements to date of what the universe looked like at this early age. Thesemeasurements have implications for many areas of particle physics and cosmology.

27


28/49

This Planck map shows the oldest light in our universe, revealing what the universelooked like 13.8 billion years ago.

Courtesy of: ESA and Planck Collaboration

The map reveals that dark matter makes up about 26.8 percent of our universe, anincrease from the previously measured 24 percent, while normal matter makes up 4.9percent rather than 4.6 percent. The results also indicate that dark energy makes up 68.3percent of the universe rather than the 71.4 percent previously estimated.

The Planck data also reveals that the universe is 13.8 billion years old and isexpanding at about 67.15 kilometers per second per megaparsec. (A megaparsec isabout 3 million light-years.) This makes the universe 100 million years older thanpreviously thought and reveals that its rate of expansion is less than previouslydetermined by data from space telescopes.

In addition, the map suggests an apparently random distribution of matter across theuniverse, suggesting that when the universe expanded at great speed in theinflationary epoch, random processes ruled the day. This discounts some of the morecomplex theories describing inflation and gives credence to the simpler ones.

Although the big picture from Planck agrees well with our cosmological models, thelevel of detail is astounding, says Marc Kamionkowski, a professor of physics andastronomy at Johns Hopkins University who was not involved in the research. Theoriststhroughout physics and cosmology will be kept awake at night for quite some timethinking about this.

Planck continues to view the sky today; the missions complete results will bereleased in 2014. These full results are expected to have implications on additional areasof particle physics and cosmology, including the number of neutrino species in theuniverse. Stay tuned!

28
http://www.symmetrymagazine.org/sites/default/files/images/standard/Planck_CMB_node_full_image-s.jpg


29/49

breaking

March 14, 2013

One step closer to the HiggsbosonIn analyses of a fundamental characteristic of the newly discoveredHiggs-like particlethe ways in which it decaysscientists see evenmore Higgs-like behavior.By Kathryn Jepsen and Ashley WennersHerron

Scientists at the Rencontres de Moriond physics conference have released a second setof updates showing that the particle that scientists at the Large Hadron Colliderdiscovered last year looks even more like the Higgs boson.

Last week, the study of two properties of the particle, its spin and its parity, also hintedthat scientists had caught the Higgs particle predicted in the Standard Model of particlephysics. But this is still not the final word.

"We're working on measuring different ways the particle is produced and decays,"

says Tim Adye, a physicist from Rutherford Appleton Laboratory who presented theATLAS experiments measurements of the Higgs-like boson's properties. "It's becomingharder and harder to believe this could be something besides the Standard Model Higgsboson."

When protons smash together in the LHC, their energies convert for a limited time intomass, bringing into being particles not involved in the collision. Those particles decay intolighter, more stable particles, often before particle detectors even get a chance to seethem.

In the case of the Higgs-like boson, scientists do not observe the particle directly.Instead, they observe the sets of lighter particles into which it decays. Physicists have

29
http://www.symmetrymagazine.org/article/march-2013/higgs-like-particle-still-looking-like-the-higgshttp://www.symmetrymagazine.org/article/march-2013/higgs-like-particle-still-looking-like-the-higgs


30/49

precisely predicted how often a Higgs will decay into different combinations of otherparticles.

In todays update, scientists showed that, with more data and updated analysis, theparticle they discovered is continuing to follow predicted decay patterns.

"This particle is remarkably consistent with the Standard Model Higgs boson," saysAndrew Whitbeck, the doctoral student at Johns Hopkins University who presented the

CMS experiments measurements. "There are still large error margins, but everything islining up for the Standard Model. It's pretty spectacular."

Only timeand more datawill tell whether the physicists have really found the Higgsthey were looking for.

30


31/49

breaking

March 12, 2013

LHCb studies particle tipping thematter-antimatter scalesThe LHCb experiment at CERN reports precise newmeasurementsbut leaves open the question of why our matter-dominated universe exists.By Kelly Izlar

Today, scientists from CERNs LHCb experiment announced new results in the study ofthe evolution of our matter-dominated universe.

The face-off between matter and antimatter was supposed to be a fair fight. The bigbang should have created equal quantities of matter and antimatter, which are identical toone another but with some opposite properties such as charge. As matter and antimatterinteracted over the past 13 billion or so years, they should have annihilated each other,stripping our young universe of its potential and leaving it a void.

But scientists think something happened in those first moments to upset the balance,skewing the advantage slightly toward matter.

Over the past several decades, scientists have found that some particles decay intomatter slightly more often than they decay into antimatter. The Standard Model of particlephysics predicts a certain amount of this imbalance, called charge parity violation.

However, the points this wins for matter cant account for the amount of it left over inour universe. In fact, calculations suggest that its not enough for even a single galaxy.Since there may be as many as 500 billion galaxies in our universe, something ismissing.

We think there has to be another source of CP violation that you dont see in theStandard Model, says Sheldon Stone, group leader of Elementary Particle Physics atSyracuse University and a member of LHCb. The source of this CP violation can be newforces carried by new particles, or even extra dimensions.

31


32/49

Physicists are looking beyond the Standard Model for another source of CP violationthat gave rise to galaxies, stars, planets and, eventually, us.

Between 1964 and 2012, physicists found that several types of mesonsparticlesmade up of quarks and antiquarksdecayed into matter more often than antimatter. Butone particle seemed different. In 2011, LHCb analysis hinted that the CP violation in Dmesons went beyond the amount predicted in the Standard Model, a possible sign of newphysics in the works.

But in results presented today at the Rencontres de Moriond physics conference inItaly, those hints of new physics have melted away, reinforcing the predictions in theStandard Model of particle physics and leaving us with the mystery of why our universe ismade of so much matter.

If we look at it as the glass being half empty, we could be disappointed that the hintfor something exciting isnt confirmed, says Tim Gershon, LHCb physics coordinatorand professor at the University of Warwick. On the other hand, there was a lot oftheoretical work suggesting models to explain effects weve seen. New results constrainthe models and tell us something about nature.

32


33/49

breaking

March 06, 2013

Higgs-like particle still looking likethe HiggsScientists have started to exclude some of the more exotic scenariosfor the Higgs-like boson.By Kathryn Jepsen

The Higgs-like boson discovered in 2012 is looking more Higgs-like, scientists onexperiments at the Large Hadron Collider said in presentations at the Rencontres deMoriond physics conference today.

On July 4, 2012, scientists first announced the discovery of a new particle that couldbe the Higgs boson. The Higgs boson is, or was, the last undiscovered particle in theStandard Model, a menu of the particles and forces that serve as the building blocks ofthe universe.

Final judgment of whether the new boson is the predicted Higgs particle will likelyhave to wait until sometime after the LHC resumes running at higher energies in 2015.But things look good so far for those rooting for a Standard Model Higgs. Continuingstudies of the properties of the boson are beginning to exclude some scenarios thatwould strip the particle of its title.

The evidence is accumulating just as it should if it is the Standard Model Higgsboson, says Fermilab theorist Chris Quigg.

Once scientists discovered the new particle, they could begin checking on a wholecollection of its predicted properties, such as how often it would decay into certaincombinations of other particles. Theyre getting closer to determining two propertiescalled spin and parity.

The Standard Model Higgs boson must have 0 spin and even parity, written as 0+.

When a particle breaks down into lighter particles, the spin and parity of a particle

33
http://www.symmetrymagazine.org/article/march-2013/spinhttp://www.symmetrymagazine.org/article/march-2013/spin


34/49

affect the angles at which those lighter particles fly. Scientists from the ATLAS and CMSexperiments studied a well-understood decay pattern of the Higgs-like particle: into a Zboson and a virtual Z boson, which then decay into two pairs of another type of particles,leptons. By studying the angles at which the decay products move away during thisprocess, scientists can figure out the spin and parity of the particle.

If the Higgs-like particle did not have a spin-parity of 0+, it would be something otherthan the Standard Model Higgs boson. That would be an exciting prospect for physicists

who would like a brand new mystery to solve. But, from what scientists have seen so far,the Higgs-like boson is behaving the way the Standard Model Higgs boson is supposedto behave.

With further analysis and data from higher-energy collisions, though, the Higgs-likeparticle will have many more chances to step off its expected path. LHC scientists willcontinue to give updates to their analyses at the Rencontres de Moriond meeting nextweek.

34


35/49

signal to background

March 27, 2013

Astronomers give Dark EnergyCamera rave reviewsEven before the Dark Energy Survey begins, the Dark EnergyCamera is exceeding expectations in the astrophysics community.By Andre Salles

Astronomer Daniel Kelson is part of a team working to answer an intriguing questionabout our universe: Why are fewer and fewer stars being created over time? Hes beencollecting data for years, but one piece of the puzzle eluded him.

That is, until December of last year, when he spent two nights in Chile observing thesky with the new Dark Energy Camera. Kelson came away from his observing sessionwith the information he needed to complete his research, and with a healthy dose ofrespect for what he calls the super camera, installed at the southern hemispherestation of the US National Optical Astronomy Observatory.

It was beautiful to use, Kelson says. Its impressive that the various teams couldcome together and make such a phenomenal camera.

Hes not alone in his appreciation.

The 570-megapixel Dark Energy Camerathe worlds most powerful digital imagingdevice, built at Fermilab and installed on the Blanco 4-meter telescope at the CerroTololo Inter-American Observatory in Chilewas constructed for the Dark Energy Survey,a five-year effort to map a portion of the southern sky in unprecedented detail. Since thecamera was turned on in November, the DES has spent 50 nights completing the scienceverification phase of the experiment.

When DES members are not operating the camera, its available for otherastronomers like Kelson to use. Since last December, 19 other groups of scientists frominstitutions including Harvard, the University of Virginia and the University of California atBerkeley have signed up for nights with the Dark Energy Camera. Some teams searched

35


36/49

for asteroids while some examined the properties of galaxies.

David Silva, Director of the National Optical Astronomy Observatory, has beenpleased with the cameras ability to tackle a wide range of astronomical problems ofpressing interest to US astronomers.

After almost a decade of anticipation, it has been extremely gratifying to see thediversity of astronomical research problems being enthusiastically investigated so early in

the lifetime of a major new instrument by astronomers from the US and abroad, Silvasays.

Kelson, who has been with the Carnegie Observatories in Pasadena since 2000, isinterested in the evolution of galaxies. Specifically, his research probes whether there issomething about galaxies themselves, or their environments, that can account for thereduction in new stars over the past 10 billion years.

To understand the process, we collected spectra for a couple hundred thousandgalaxies over the last several years, he says. We hope to understand how the evolvinggalaxy environments affect changes in star formation.

Kelsons research group targeted three specific areas of the sky, thinking that goodoptical images had been taken in all three. But two of the fields, he said, had not beenphotographed in the detail required. So he and five other Carnegie Institution scientistsused the Dark Energy Camera in December to take the images they needed.

The camera was still in the commissioning phase, in what is called shared risk time.Using a complex piece of machinery during shared risk time, Kelson says, often leads toglitches, crashes and other setbacks as the devices are fine-tuned. But, he says, his timewith the Dark Energy Camera was smooth.

It was impressive that it worked so well so early, he says. It didnt crash on meonce, and it worked beautifully.

Anja von der Linden had a similar experience. An astronomer with the Kavli Institutefor Particle Astrophysics and Cosmology at SLAC and Stanford, von der Linden spent 10nights with the camera at the end of January and the beginning of February measuringthe masses of clusters of galaxies.

Von der Linden's team used a technique called weak gravitational lensing, one ofthe specialties of the Dark Energy Camera. The camera can capture quality images overa large field of view, allowing astronomers to observe many galaxies at once, measuringtheir distortion due to lensing effects of foreground clusters.

The camera has been working great. It is certainly set up to make observing veryefficient, she says, praising the cameras auxiliary charged coupled devices, which aid

in focusing the telescope, and its on-the-fly image processing, allowing users to quicklyestimate the quality of the picture being taken.

She noted one of the many tweaks still being made to the camera and the telescopeduring her time therea new chiller to cool down the mirror during the day, to prevent theslight washing out of the images partially due to temperature changes in the mirror.

Von der Lindens team shared observation nights with the Dark Energy Survey, andshe says the collaboration members were extremely helpful to her before, during andafter her observation time.

I have asked many DES members many questions, and they have been extremely

36


37/49

forthcoming in providing insights, she says.

Community time with the Dark Energy Camera is booked through mid-March, whenthe observation season ends. The Dark Energy Survey will officially begin in September2013 and will spend 525 nights over the next five years searching for the secrets behinddark energy.

And during the other 400 or so nights, when the astrophysics community gets to use

the camera for other experiments, who knows what wonders will be discovered?

37


38/49


March 22, 2013

Great minds lauded at physicsprize ceremonyA crowd full of stars from the field of particle physicsalong with onefrom Hollywoodcelebrated recent achievements.By Ashley WennersHerron

You can think of this as the Oscars, but instead of movie stars, youre with the greatestminds in the world, said actor Morgan Freeman at an award ceremony on Wednesday inGeneva, Switzerland.

The comment garnered laughter from the hundreds of scientists who had forgone theirnormal uniforms of jeans and sneakers for tuxedos and ball gowns. It takes a lot for somephysicists to trade comfort for fashion, but the opportunity to celebrate workaccomplished over the past five decades was too good to pass up.

The crowd had gathered for the presentation of the Fundamental Physics Prize, anannual award established by Russian billionaire and physics enthusiast Yuri Milner torecognize outstanding achievements in physics. Last December, a selection committeemade up of previous winners announced five semi-finalists in the running for this year'sprize.

The committee also gave special awards to British theoretical physicist StephenHawking, for his discovery of Hawking radiation, the emission of which causes blackholes to lose energy and mass; and to seven scientists from the Large Hadron Collider,for their contributions to the search for the Higgs boson.

Hawking took the stage as his daughter, Lucy, accepted the award on his behalf. As aresult of a disorder that causes muscle weakness called amyotrophic lateral sclerosis,Hawking uses a speech-generating device and a motorized wheelchair.

I would like to thank Yuri Milner for establishing the foundation to recognize work thatmay never be recognized by the Nobel committee, since much of it is impossible to prove

38


39/49

experimentally, said Hawking in the computerized voice that has become his own. Inever thought my discovery would be confirmed or recognized.

He summarized the theory of a no-boundary universe, proposed with fellow theoristJames Hartle, which suggests that time didnt exist prior to the big bang. Since then, hesaid, time has existed, but in an unlimited wayevery timeline of every possibility exists indifferent branches of the universe.

I have a sense of achievement to make these contributions despite having ALS, hesaid, adding new meaning to the name of his theory: My motto is there are noboundaries.

Freeman then introduced the physicists recognized for their contributions at the LargeHadron Collider. Physicists on two experiments, CMS and ATLAS, announced in summer2012 that they had discovered a new particle that is likely the theorized Higgs boson thatphysicists had been hunting since 1964.

The special award was shared among seven physicists (shown in the slideshow at thebottom of the page):

Lyn Evans, who led the construction of the LHCPeter Jenni, ATLAS spokesperson from 1994 to 2009Fabiola Gianotti, ATLAS spokesperson from 2009 to early 2013Michel Della Negra, CMS spokesperson from 1992 to 2006Tejinder Jim Virdee, CMS spokesperson from 2007 to 2010Guido Tonelli, CMS spokesperson from 2010 through 2011Joe Incandela, CMS spokesperson since 2012

Each recipient said the $3 million award and recognition belonged to the thousands ofphysicists involved in the work.

When the time came to reveal the winner of the 2013 Fundamental Physics Prize,Alan Guth, one of the 2012 laureates, took the stage with the unopened envelope.

During Hawkings discussion of no-boundary theory, Hawking had referred to wavefunction collapse, a phenomenon in quantum mechanics in which a superposition ofseveral possible states is narrowed to a single reality after interaction with an observer.

Alan, will you please collapse the wave function? Freeman joked.

Guth took the opportunity to mention that, according to the no-boundary theory, thereexist realities in which every laureate is the winner of the 2013 Fundamental PhysicsPrize.

But the winner in this branch of the universe, he announced, is AlexanderPolyakov, a theorist known for his work with field theory and string theory.

Concluding the ceremony, Freeman said that the work of fundamental physics is notdone. There is more to explore and more to discover.

It will be difficult and not always appreciated, but our laureates will not rest on theirlaurels, Freeman said.

As 2012 award-winner Andrei Linde said earlier in the program, I tell students, Ifyou can avoid being a physicist, do it. But its like if youre a poet. You cant stopwriting poetry. Itll hurt.

39


40/4940


41/49

signal to backgroundMarch 20, 2013

Meet 63 women in STEM, andcountingIn celebration of Womens History Month, the US Department ofEnergy is recognizing some of the many women who make adifference in science and technology innovation.By Kelen Tuttle

Across the US Department of Energys national laboratories, field offices andheadquarters, thousands of women dedicate their days to science, technology,engineering and mathematics. Now, on a website launched this week, 62 of them sharetheir stories, revealing what prompted them to pursue science careers and how theyvemade a difference in the years since.

Their stories vary, but one constant is the presence of mentors and role models.

Dana Thayer, for example, grew up near Fermilab and was introduced to particlephysics at a young age through mentors at the labs Saturday morning physicsprograms. Thayer quickly became enthralled by the fields huge machines and hasnt

looked back since. She now leads the data acquisition team for SLACs Linac CoherentLight Source.

As she started her career, Thayler says, I learned the most from working with andlearning from other people. Good ideas really benefit from different perspectives and thebest work is never done in a vacuum.

Likewise, when Kawtar Hafidi was a young student in Morocco, her fatherwhohimself hadnt graduated from high schoolencouraged her to study science because hefelt it would be useful to their country. Hafidi did, and says she loved every minute of it.

Hafidi recounts that one day her teacher asked her why she hadnt done her mathhomework problems. I said, I don't want to. He asked me why, and I said, Because

41


42/49

I'm afraid they will be finished! We didn't have many books at that time, she says, soI'd find one book and do just one problem a day, like eating a cake, you knowyou don'twant to be finished.

These days, Hafidi has plenty of problems to solve as an experimental physicist atArgonne National Laboratory. There, she studies how quarks and gluons, twofundamental particles, come together to form nucleons and nuclei. The quest forknowledge and discovery excites me, she says. The more we understand, the more we

can do.

Aliya Merali wholeheartedly agrees. As science educator at the Princeton PlasmaPhysics Laboratory, Merali often calls on her training in plasma research, work on theCryogenic Dark Matter Search, and NASA collaborations that resulted in severalmicrogravity flights aboard the Weightless Wonder (pictured above). In her current role,she coordinates events and activities to encourage students to consider science careers.

I believe that our country needs to make the STEM fields more accessible to theyouth, she says. A strong stigma exists about the scienceswe often present them toour students through media and society as fields that only the elite few are capable of.Ultimately, I believe that if we change the way we present the sciences to the youth by

highlighting the underrepresented and non-stereotypical members of the STEM fields, thesocial stigma will deteriorate.

Read more about Aliya Merali, Kawtar Hafidi, Jana Thayer and 59 other women in

STEM on theDepartment of Energys website.

42
http://energy.gov/diversity/listings/women-energyhttp://energy.gov/diversity/listings/women-energy


43/49


March 20, 2013

Research with flair at FameLab2013Young scientists presented their research in three entertainingminutes at this years Swiss semifinal round of Famelab 2013,hosted by CERN.By Kelly Izlar

And now presenting our next contestant on Swiss Idol, Piotr Traczyk, said University ofMichigan physicist and temporary Master of Ceremonies Steve Goldfarb.

A young man with long hair and with a red electric guitar slung across his shoulderstrode across a stage in front of an audience gathered on March 16 at CERN laboratory,located on the border of Switzerland and France.

Wait This isnt Swiss Idol, Goldfarb said with mock chagrin. This is FameLab!Can you talk about science?

Traczyk displayed his guitar to the audience so they could see an ornate mosaic ofpuzzle pieces forming the image of the CMS detector pasted across its front.

Well I happen to be a physicist, too, said Traczyk, a member of the CMScollaboration. So I bet I can think of something to say.

FameLab, a blend of science fair and talent show, was launched in 2005 byCheltenham Festivals in partnership with the UKs National Endowment for Science,Technology and the Arts, to find and nurture scientists and engineers with a knack forcommunicating science. Competitions are held in 20 countries across Europe, Asia,Africa and North America and so far have attracted more than 3800 researchers.

Traczyk, a Polish postdoctoral student at the University of California, Los Angeles,was one of 20 young researchers who participated in the Swiss semifinal round ofFameLab 2013. He won second place with his talk, which used puzzle pieces to explain

43


44/49

how scientists at the Large Hadron Collider search for missing bits of the Standard Modelof particle physics.

The first-place winner, Divya Ail from the University of Zurich, used humor and propsto explain how using Viagra can affect a persons vision.

This is a way to foster the interaction between scientists and the public, saysAntonella Del Rosso, member of the CERN Communication Group and organizer of this

years Swiss FameLab semifinal. They are only given three minutes, so its achallenge. But they are eager to explain their research and how important it is.

Contestants for this round of FameLab work at universities or institutions acrossSwitzerland. Participants enchanted and educated their live audience, online spectatorsand a panel of judges by presenting on issues including how to fight cancer with physicsand why birds fly in a V-shaped formation.

I think its important to communicate science to the general public, says NazimHussain, a contestant and University of Oxford physicist from the LHCb experiment atCERN. People are interested, but they might be intimidated by what they see in themedia. Its easy to dismiss something because its complicated.

Of the 20 contestants, 10 were selected to go on to the Swiss FameLab Finals inZurich on May 24. Winners from that round will continue on to the FameLab InternationalFestival in Cheltenham in June.

44


45/49


March 15, 2013

A different spinIn physics, spinors are used to plot the spin properties of elementaryparticles. In Stanford's recreational softball league, it's a wholedifferent story.By Glenn Roberts Jr.

Sporting both physics and physique, SLAC National Accelerator Laboratory employeesfield a slow-pitch, co-ed softball team each year, the Spinors, in a Stanford University

recreational league. Although their competitors are a mostly younger bunch of graduatestudents and staff, the SLAC team likes to think they have physics in their favor.

In physics, spinors are used to plot the spin properties of elementary particles. Firstdescribed by French mathematician lie Joseph Cartan in 1913, spinors have a range ofapplications in modern physics and mathematics. They also share a pronunciation withspinnersbaseball slang that describes curveballs and sliders, which are pitchesthrown with heavy spin on the ball.

The teams logo even features two softballs smashing together, with smaller spheresbursting out of the impactpaying homage to the labs particle collider experiments.

Softball traditions run deep at SLAC; physics faculty and students engaged in annualsoftball championship games on the Stanford campus as far back as the 1950s, evenbefore the 1962 groundbreaking for the labs two-mile-long linear accelerator. Sincethen, an annual softball game remains an unbroken tradition.

Team manager Mike Woods, a 21-year Spinors veteran, says that since the Spinorsfirst formed in 1991, the team has evolved to include a representative slice of SLACsworkforce: men and women, ranging in age from their 20s to their 80s, who trade hits andruns with teams that are often quite a bit younger.

Woods describes the Stanford recreational league as very laissez faire, verysocialweve never even had hired umpires. Based on work schedules and availability,

45


46/49

its common for a different set of players to show up to each game.

And although the Spinors havent yet won the league championship, theyll be backagain next year for another try.

46


47/49


March 11, 2013

Linear collider focus gets down tosizeIn a display of timing worthy of a blockbuster movie, a multinationalteam of accelerator physicists focused a beam of electrons down tothe tiny size needed for a future linear collider the same week thatthe linear collider board formed.By Lori Ann White

In late 2012, Toshiaki Tauchi clicked the send button on an email with the subject line70nm achieved at ATF2! It signaled a major success for Tauchi, an acceleratorphysicist at KEK, and his colleagues at the Japanese labs Accelerator Test Facility 2:They had shown they could focus a beam of electrons down to the tiny size required by afuture linear collider.

Tauchi is a member of the executive committee overseeing the global design effort forthe International Linear Collider, and the timing of his announcement could not have beenbetter.

Just the day before, Fermilab Director Pier Oddone, in his role as chair of the

International Committee for Future Accelerators, announced the formation of a LinearCollider Board to shepherd the global effort to build a linear collider capable of pushingback the frontiers of high-energy physics revealed by the Large Hadron Collider at CERN.With Japan expressing interest in hosting such a facility and the even more recentformation of a Linear Collider Collaboration to coordinate and advance global plans,momentum seems to be building for the construction of the giant electron-positroncollider.

Coaxing particle beams to a tight, accurate focus is vital for any collider, says GlenWhite, an accelerator physicist from SLAC National Accelerator Laboratory who has beenracking up frequent flier miles to Japan since late 2008 to work at ATF2. The test facilitycontains a prototype of an advanced optics design intended for use at the ILC, and

47


48/49

researchers have been using it to squeeze down the electrons in the beam into tighterbunches. Packing electrons into smaller bunches helps maximize particle collisions, andmaximizing collisionsalong with maximizing the energy of the collidingparticlesmaximizes the science. That relationship holds for all colliders.

We are very dependent upon novel beam focusing schemes, such as the one weuse at ATF2, to get the very small beam spot sizes required to deliver the promisedphysics, White says. This means ATF2 is a prototype of the final focus for any future

linear collider, and not just for the ILC in its current design incarnation as captured bythe Technical Design Review, also completed last December.

In addition to prototyping the optics for focusing the beam, the ATF2 team neededdiagnostic instruments capable of telling them whether or not the optics were workingcorrectly. Old diagnostic instruments arent much good tracking beams smaller than amicrometer in size, White says. So the team assembled a whole new suite ofinstruments, including making significant improvements to a beam size monitor that madeits debut at the Final Focus Test Beam, the ATF2s precursor, at SLAC. Called theinteraction point beam size monitor, this equipment uses laser interferometry to measurethe diameter of the beam at its most important location: the interaction point whereparticle bunches collide.

But an accelerator is more than its components, and the ATF2 needed to prototypemore than the optics to focus the beams and the diagnostic instruments to track them.Two stated goals of the ATF2 project were to prototype the operation of a complexaccelerator in an international setting and to educate the next generation of acceleratorphysicists and operatorswhatever their country of origin. The facility is an internationaltest facility for linear colliders and instrumentation, says White. Its a big globalcommunityanother requirement for any future linear collider.

ATF2 met those goals, says White, thanks to a final eight-week push to reach the70-nanometer spot size. The extra time spent learning the accelerators idiosyncrasiesproved vital, especially when an elusive problem with the accelerator blocked furtherprogress near the end of commissioning.

We shut down the beam at about 10 p.m. and we basically tore the machine apart,White says. From the most senior physicist to the youngest student, Everyone grabbeda wrench and headed for the accelerator. By three in the morning we had the wholemachine laid out on the floor. He smiles.

That was a great bit of international collaboration, he says, and one that paid offhandsomely. The problem-solvers used what theyd learned in the previous severalweeks to rebuild the machine, swapping around parts and testing the resultingelectromagnetic fields. When they fired the beam up, lo and behold, the beam stabilized.

But achieving the small beam size is just the start. Its a two-stage program here,

White says. First we make the small beam size and then we maintain it. In the next fewyears well learn a lot of valuable information about how the ILC will perform.

48


49/49

Copyright 2013 symmetry

[new symmetry issue] april 2013.pdf

Documents