Friday, July 19, 2013

Have a safe day!

Friday, July 19

Special Particle Astrophysics Seminar (NOTE DATE, TIME, LOCATION) - WH6NW
Speaker: Javier Tiffenberg, Fermilab
Title: DAMIC: A Novel Dark Matter Experiment

3:30 p.m.

4 p.m.
Joint Experimental-Theoretical Physics Seminar - One West
Speaker: Ashish Kumar, SUNY Buffalo
Title: Sampling the QCD Soup with Massive Vector Bosons and Heavy Flavor

8 p.m.
Fermilab Lecture Series - Auditorium
Speaker: Chris Lintott, University of Oxford
Title: How to Discover a Planet From Your Sofa
Tickets: $7

Monday, July 22


3:30 p.m.

4 p.m.
All Experimenters' Meeting - Curia II
Special Topic: Superconducting Cavity Processing Progress

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Wilson Hall Cafe

Friday, July 19

- Breakfast: chorizo and egg burrito
- Breakfast: blueberry-stuffed French toast
- Breakfast burger
- Seafood linguine
- Barbecue chicken
- Barbecue pork spare ribs
- Turkey and cucumber salad wraps
- Strawberry summer salad with chicken
- Texas-style chili
- Vegetarian chili

Wilson Hall Cafe menu
Chez Leon

Friday, July 19

Wednesday, July 24
- Bacon cheese stuffed shells
- Field greens with herb vinaigrette
- Fresh fruit plate

Chez Leon menu
Call x3524 to make your reservation.


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ORKA experiment aims to observe ultra-rare decays

Summer workers help prepare the CDF central detector for the possible future installation of ORKA. Photo: Reidar Hahn

CDF may have stopped collecting data in late 2011, but its detector hall is currently being repurposed to possibly house an experiment designed to observe one of the rarest events in particle physics.

The proposed experiment, called ORKA, would observe the decays of charged kaons, looking for a specific decay chain into a charged pion and two neutrinos.

The "OR" in the experiment's name is a nod to the rarity of the event. It comes from oro, the Spanish word for "gold," a metal as valuable to the world as this particular charged-kaon decay is to particle physics.

In fact, when an experiment at Brookhaven first observed the decay, it became among the rarest ever captured. Brookhaven observed seven events in five years; ORKA's team is aiming for 1,000 in the same time period.

"There's a long history at this lab of studying rare kaon decays because, from those decays, we may have indications of new physics," said scientist Jonathan Lewis, a member of the ORKA team. "This is a technique that's been done many times before, but we're advancing technology so we can do better."

Inside a charged kaon is a strange quark; a charged pion has a down quark. This means that a decay from a positively charged kaon to a positively charged pion and two neutrinos is a flavor change—from strange to non-strange—but the charge remains the same, a decay known as a flavor-changing neutral current. In the Standard Model, this particular decay occurs about seven times per 100 billion events. But new physics, such as supersymmetry, could increase this rate to 20, or even 50, per 100 billion decays.

"There are a handful of processes in the Standard Model where the noise from the Standard Model is way, way down, and these flavor-changing neutral currents are quite powerful in that way," said Bob Tschirhart, Fermilab scientist and spokesperson for ORKA. "That allows new physics from supersymmetry, for example, to come up above the noise so that we can see it."

But before ORKA can begin its work, it has to be installed first—and that means disassembling CDF. The 2,500-ton CDF central detector was recently mounted on eight rollers and, using hydraulics, moved out of the beamline to be worked on. The plug has been removed, allowing the removal of the CDF tracking detectors from inside the solenoid and creating the area where the ORKA detector could be inserted. Once the detector is built, scientists will send a beam of protons into a platinum target about the size of a pen, producing particle showers, including charged kaons, for the team to study.

Read more

Laura Dattaro

Press Release

Discovery of rare decay narrows space for new physics

After a quarter of a century of searching, physicists have discovered a rare particle decay that gives them an indirect way to test models of new physics.

Researchers on the CMS and LHCb collaborations at the Large Hadron Collider at CERN announced today at the EPS-HEP Conference in Stockholm, Sweden, that their findings agreed closely with the Standard Model of particle physics, ruling out several models that predict new particles.

In this result, physicists showed for the first time enough evidence to declare the discovery of a decay of a particle made up of two kinds of quarks—antibottom quarks and strange quarks—into a pair of particles called muons.

The U.S. Department of Energy's Fermi National Accelerator Laboratory serves as the U.S. hub for more than 1,000 scientists and engineers who participate in the CMS experiment. DOE and the National Science Foundation support involvement by about 2,000 scientists and students from U.S. institutions in the LHC experiments CMS, ATLAS, LHCb and ALICE—the vast majority participating at their home institutions via a powerful broadband network that ships data from CERN.

Read more

In the News

New results from T2K conclusively show muon neutrinos transform to electron neutrinos

From, July 19, 2013

Today at the European Physical Society meeting in Stockholm, the international T2K collaboration announced definitive observation of muon neutrino to electron neutrino transformation. In 2011, the collaboration announced the first indication of this process, a new type of neutrino oscillation, then; now with 3.5 times more data this transformation is firmly established. The probability that random statistical fluctuations alone would produce the observed excess of electron neutrinos is less than one in a trillion. Equivalently the new results exclude such possibility at 7.5 sigma level of significance. This T2K observation is the first of its kind in that an explicit appearance of a unique flavor of neutrino at a detection point is unequivocally observed from a different flavor of neutrino at its production point.

Read more

Physics in a Nutshell

How real is relativity?

Rotating a picture frame mixes horizontal and vertical in much the same way that relativity mixes space and time.

Special relativity is a well-established fact of nature. Although we rarely encounter relativistic effects in everyday life, they are routine in the world of subatomic particles and in the cosmos. Objects traveling close to the speed of light become spatially compressed and experience time at a slower rate. For example, lead nuclei in a stationary brick are roughly spherical, but when these same nuclei accelerate and collide in the LHC, they flatten into pancakes that collide face-on. Particles resulting from the collision, such as kaons, take a longer time to decay than stationary kaons because their internal clocks run slower. These are all measurable effects that have been observed in colliders for decades.

But how real is this stretching of time and squashing of length? Perspective makes faraway objects look small and nearby objects look large, but we do not say that they really are smaller when they're farther away. This is because the same object can look small to a faraway person and large to a nearby person at the same time. We usually don't call an effect real unless it is consistent among observers.

The way relativity works is similar to rotation. Suppose you hang a painting on the wall and align it well. The horizon line in the painting is parallel to the baseboard on the wall. Tilt the painting 45 degrees, however, and now the painting's horizon is half-horizontal and half-vertical. A horizontal ruler would measure a shorter horizon than a ruler aligned with the painting (1.41 times shorter: Try it!). Special relativity is this same phenomenon in time and space, rather than in horizontal and vertical.

To understand relativity, one must first think of time as a dimension. Imagine a flip-book, a stack of cards that shows an animated cartoon when you flip through them. Time is like the depth of the stack—every moment in time is a three-dimensional picture, stacked in some unvisualizable fourth direction. It can even be measured in units of length: 1 nanosecond of time is approximately 1 foot long. A stationary object is like a tower in time, in the same spot on each page of the flip-book. A moving object is like a leaning tower, slightly offset from page to page.

Tilting an object in space-time is much like tilting a painting on the wall. Just as the painting's horizon line occupies less horizontal space when tilted, a fast-moving nucleus occupies less space in the direction of motion—this is why it flattens like a pancake. And since part of its spatial extent has rotated into the time direction, its temporal extent lengthens—this is why its time slows down. (There is a mathematical difference between rotation and relativity, but the two are very closely related.)

So is relativity real or not? Like perspective, relativistic effects depend on your point of view: To a high-speed nucleus, we look flattened and it stays round. That's the "relative" part of relativity. But unlike perspective, time dilation can have lasting effects. An astronaut who spends many years cruising at relativistic speeds would be physically younger than her twin when she gets back. Taking a shorter path through time has consequences that don't depend on point of view.

Jim Pivarski

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Photo of the Day

Summer sunrise

The sun rises over the bison farm. Photo: Ed Dijak, PPD

Today's New Announcements

Benefits Office closed July 23-26

NALWO tour to Garfield Farm - July 31

Fermilab Prairie Plant Survey (Quadrat Study) - today

NALWO potluck supper - today

Chris Lintott: How to Discover a Planet From Your Sofa - today

Yoga begins July 23

UEC/FSPA presentation for Fermilab, Argonne postdocs, students - July 24

What's Your Financial IQ Challenge runs from July 1 - 31

July EAP webinar

C2ST presents The Physics of Baseball - Aug. 2

Puppet Fundamentals course offered in September

Poster contest for the CMS experiment

Same-sex couples now eligible for immigration benefits

Outdoor soccer at the Village

English country dancing at Kuhn Barn

Scottish country dancing meets Tuesday evenings in Auditorium

International folk dancing in Auditorium for summer

Fermilab discount at Don's Auto Ade Inc.

Bristol Renaissance Faire discount

Find new classified ads on Fermilab Today.