Thursday, April 18, 2013

Have a safe day!

Thursday, April 18

2:30 p.m.
Theoretical Physics Seminar - Curia II
Speaker: Thomas Gregoire, Carleton University
Title: Electroweak Symmetry Breaking in Supersymmetric Models with a U(1)R Lepton Number

3:30 p.m.


Friday, April 19

1 to 2:30 p.m.
All Scientists Meeting - One West

2 p.m.
Special Particle Astrophysics Seminar (NOTE DATE AND LOCATION) - Curia II
Speaker: Christoph Weniger, University of Amsterdam
Title: Gamma-Ray Lines in the Fermi LAT Data?

3:30 p.m.

4 p.m.
Joint Experimental-Theoretical Physics Seminar - One West
Speaker: Freya Blekman, Vrije Universiteit Brussel
Title: Searches for New Physics in Topologies Containing Beyond-Two-Generations Quarks at CMS

Click here for NALCAL,
a weekly calendar with links to additional information.

Ongoing and upcoming conferences at Fermilab


Take Five

Weather Severe thunderstorms

Extended forecast
Weather at Fermilab

Current Security Status

Secon Level 3

Current Flag Status

Flags at half staff

Wilson Hall Cafe

Thursday, April 18

- Breakfast: sausage gravy omelet
- Green pork chili
- Surfside tuna melt
- Mom's meatloaf
- Smart cuisine: finger-lickin' oven-fried chicken
- Crispy buffalo chicken wrap
- Assorted pizza
- Greek chicken salad

Wilson Hall Cafe menu

Chez Leon

Friday, April 19
- Spinach salad
- Alaskan crab legs
- Parsley potatoes
- Grilled asparagus
- Lemon panna cotta with blueberry sauce

Wednesday, April 24
- Chopped-shrimp Waldorf salad
- Strawberry cheesecake

Chez Leon menu
Call x3524 to make your reservation.


Fermilab Today

Director's Corner

Frontier Science Result

Physics in a Nutshell

Tip of the Week

User University Profiles

Related content


Fermilab Today
is online at:

Send comments and suggestions to:

Visit the Fermilab
home page

Unsubscribe from Fermilab Today

Special Announcement

Be cautious when traveling today

Parts of Fermilab grounds are flooded. Be careful when driving on and off site today. Photo: Reidar Hahn

Because of the recent heavy rains, the lab is experiencing some localized flooding conditions along roadways and near ponds. In some cases, traffic may need to be rerouted, and parking areas are being restricted. Please follow all signage and be cautious when traveling both on and off site today.


Liquid-argon time projection chamber gets a test fit

A 6-ton time projection chamber now sits inside the MicroBooNE cryostat. Photo: Sarah Khan

Recently MicroBooNE's liquid-argon time projection chamber, the largest in the United States, was successfully test-fitted inside a roughly 15-ton cryostat at the former DZero assembly building.

The process was similar to fitting a square peg into a round hole. In fact, it was exactly like that.

"We all had a few sleepless nights over this test fit, so we're glad to see that it went smoothly," said MicroBooNE construction co-manager Jennifer Raaf.

The 10-meter-long TPC's corners cleared the cryostat's sides by just a few inches. The snug fit maximizes the volume of "active" space to detect drifting electron streams that ultimately come from neutrinos.

Fermilab workers mounted the TPC on a trolley of old railroad tracks and moved it into the cryostat where it was secured. The whole process took a few hours of careful moving, said University of Cincinnati graduate student Ryan Grosso.

Inserting the TPC into the cryostat was a meticulous task, Raaf said.

"We needed to know precisely where everything would be situated in the tank," Raaf said. "The test fit is one of the things we've been dying to do."

Part of the reason for the test fit was determining whether the fragile detection wires at one end of the TPC would break during installation and operation.

The team used sample wires for the test fit to ensure that there were no interferences that could break a wire while pushing the TPC into the tank, Raaf said. Once they remove the TPC, the team will install more than 8,000 real detection wires.

Wires breaking during the detector operation could be a "huge setback," Grosso said, so they must be at the right tension when they're installed.

"We've practiced installing the wires before, but there is no room for mistakes this time," Grosso said.

The team is setting up a clean room at the cryostat's front end where the wires will be installed next month.

Assembly of the TPC started last July. Once the wires are installed, the team will be ready to permanently install the TPC.

"I'm really happy with the progress we've made so far," Raaf said.

Sarah Khan

Photo of the Day

What light through single surface breaks

"Mobius Strip" shimmers at night. Photo: Steve Krave, TD
In the News

New particle detector records first 3-D tracks

From DOE Pulse, April 15, 2013

The NOvA particle detector, under construction in northern Minnesota, has begun recording its first three-dimensional images of particles. At its current size, the detector catches more than 1,000 cosmic rays per second. A webcam documents the progress of the construction of the humongous detector.

This summer, DOE's Fermi National Accelerator Laboratory, located in Batavia, Ill., will start sending a beam of neutrinos every 1.3 seconds to the NOvA detector—500 miles straight through the Earth; no tunnel is necessary.

Read more

Frontier Science Result: DZero

Precise measure of matter preference

Most matter and antimatter annihilated each other in the very early universe, but a small excess of matter remained to form the universe we live in today. To attempt to understand this imbalance, scientists measure particle decay processes that show a difference between matter and antimatter.

We live in a universe filled with matter, with no detectable pockets of antimatter, but don't fully understand why. In the very early universe, matter and antimatter were created in equal abundance. As the universe cooled, the matter and antimatter annihilated each other, but left behind the small excess of matter that accounts for all of the stars, planets and galaxies in the universe today. This difference is thought to result from the slightly different ways the particles and antiparticles decayed. However, the decay rate difference predicted by the Standard Model is not nearly enough to account for the amount of matter in the universe. By precisely measuring processes that show a difference between matter and antimatter, physicists attempt to understand what caused the imbalance that led to the universe today.

The Standard Model predicts a small difference in the decay rates for the matter and antimatter versions of certain processes. Measuring a difference greater than expected could indicate physics beyond the Standard Model that could help explain the abundance of matter in the universe. Many asymmetric decays involve mesons, or the combination of a quark and an antiquark. A recent result at DZero studied this asymmetry in the decay of a charged B meson, made of a bottom quark and an up quark, into a J/Ψ meson and a charged K meson, which involves the bottom quark decaying into a strange quark and two charm quarks. To reduce the uncertainty on the measurement, the analysis exploited the fact that the magnetic polarities of magnets in the DZero detector were systematically flipped during the decade of data collecting for Run II. Each possible source of bias in the measurement of asymmetry between matter and antimatter was carefully studied and accounted for.

The final result is the world's most precise measurement of matter-antimatter asymmetry in charged B meson decays to a J/Ψ meson and a charged K meson. The measured asymmetry is consistent with the Standard Model. While it does not indicate the presence of new physics and explain the matter-antimatter asymmetry in the universe, it is an important step in exploring this mystery.

Mike Cooke

Iain Bertram (Lancaster University, United Kingdom) led this analysis effort.
The "deans" of the University of DZero organize monthly academic-style lectures for the DZero collaboration, targeted towards young physicists in particular, on a broad range of topics of interest to modern particle physicists.
In the News

Homing in on dark matter

From Sky & Telescope, April 16, 2013

Not to be outdone by the noncommittal announcement two weeks ago of a possible dark matter signal in space, an international team working deep in a Minnesotan mine has announced their own potential detection. This time, the detection—if that's what it is—is a direct one: three events that might be from dark matter particles scattering off atoms in silicon wafers used by the Cryogenic Dark Matter Search (CDMS) collaboration.

Read more


Today's New Announcements

Barn Dance - April 21

Lecture: Big Science, Big Challenges - May 16

Lawyers discuss permanent residence process - today

Lunch & Learn: 10 Quick Steps for Fitness Goals - today

Fermilab Arts Series: Barynya: Music & Dance of Russia - April 20

UChicago: Willy Wonka - movie and science demos - April 21

Engineering Group to hold seminars at Fermilab - April 26

Changes to U.S. visa procedures - begin April 30

Hubbard Street 2 Dance - Fermilab Arts Series - May 11

Fermilab-CERN Hadron Collider Physics Summer School open for applications

Reminder - FSA debit card PIN required

International folk dancing meets Thursday evenings in Kuhn Barn

Indoor soccer

Fermilab Golf League

Indian Creek Riding Club

Chicago Fire discount tickets