Fermilab TodayThursday, February 10, 2005  

Thursday, February 10
2:30 p.m. Theoretical Physics Seminar - Curia II
Speaker: F. Cachazo, Institute for Advanced Study
Title: New Techniques in Perturbative Gauge Theory: Tree and One-Loop Calculations
3:30 p.m. DIRECTOR'S COFFEE BREAK - 2nd Flr X-Over

Friday, February 11
3:30 p.m. DIRECTOR'S COFFEE BREAK - 2nd Flr X-Over
4:00 p.m. Joint Experimental Theoretical Physics Seminar - 1 West
Speaker: T. Tait, Argonne National Laboratory
Title: Z' Searches in Run II

Weather Mostly Sunny 30º/19º

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Thursday, February 9
Minnesota Wild Rice with Chicken
Tuna Melt on Nine Grain $4.75
Breaded Veal with Mushroom Cream Sauce $3.75
Sweet & Sour Pork over Rice $3.75
BLT Ranch Wrap $4.75
Cheesey Breadsticks $2.25
Chicken Pecan Salad $4.75

The Wilson Hall Cafe now accepts Visa, Master Card, Discover and American Express at Cash Register #1.

Wilson Hall Cafe Menu
Chez Leon will be closed through January and February

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Universities Help on the Tevatron
This article is the fifth in a series that will focus on the benefits of Fermilab/University collaboration on different accelerator projects.
Kip Bishofberger
Kip Bishofberger with a prototype of the TEL electron gun. (Click on image for larger version.)
Many university accelerator projects involve solving problems or improving performance. "Accelerator physicists work on a tight schedule," said Alvin Tollestrup of Fermilab's Experimental Particle Physics Division. "Most universities have little experience with the accelerator environment — the 24-hour monitoring and all the potential repercussions of the system on other experiments."

One successful collaboration includes the building of the Tevatron Electron Lens (TEL), which started in 2000 at the beginning of Run II. The TEL, attached to the Tevatron, performs two functions. When opposing proton and antiproton bunches collide, only a few particles actually interact, but the other particles are slightly scattered. In "beam-beam compensation" the TEL shoots an electron beam that interacts with the antiprotons, which reverses this scattering and keeps the bunches compact. Additionally, the TEL "sweeps out" particles that have escaped from the bunches into the abort gap, an issue that otherwise would severely handicap the Tevatron.

"The TEL is the only thing in the Tevatron that can be adjusted fast enough to target each bunch independently," said Bishofberger. "After installing it, we succeeded in our goals within a couple months. Today, the first TEL is being used continuously and a second TEL is being built. I'm so excited to be part of a project that has such an immediate effect on today's colliders. It's making a difference right away."

Other university groups contributing to Tevatron performance include Ludovic Nicolas from the University of Glasgow, who is working with Nikolai Mokhov on beam vacuum effects as well as radiation background simulations. "Fermilab is like a great playground for students doing research," said Nicolas. Also, Jia Ning from the Illinois Institute of Technology is working with Chen-Yang Tan of the Accelerator Division on a transverse beam frequency response simulator, which will conserve machine studies time. Carol Johnstone and Valeri Lebedev of Fermilab's Accelerator Division have worked with Michigan State University students on beam lattice calculations, as well.
Next: ILC

Accelerator Update
February 7 - February 9
- During this 48 hour period Operations established one store that combined with an existing store provided the experiments with approximately 26 hours and 19 minutes of luminosity.
- A quench ended store 3969
- The Main Injector held off due to ground fault indication
- MI-50 suffered a switch gear failure

Read the Current Accelerator Update
Read the Early Bird Report
View the Tevatron Luminosity Charts

In the News
FYI: AIP Bulletin of Science Policy News, February 9, 2005
Tight Budget Times: DOE Office of Science FY06 Request
The underlying theme at the release of the Department of Energy's FY 2006 budget request was the need to rein in federal spending. The total DOE budget would drop 2.0 percent under President Bush's FY 2006 budget request, from $23.9 billion in FY 2005 to $23.4 billion. For DOE's civilian research, the Office of Science (SC) would see its budget reduced by 3.8 percent from FY 2005 funding of $3,599.6 million to $3,462.7 million. The FY 2006 requested amount is, in fact, also 2.0 percent lower than the office's FY 2004 funding. According to DOE documents, much of the reduction comes from the elimination of $79.6 million in congressionally directed earmarks to Biological and Environmental Research, and the reduction to the budget for core SC programs is only 1.6 percent.
read more

Fermilab Result of the Week
Delving for Dibosons at DZero
End-on view of one of three WZ events. The collision occured at the center of the detector. A Z boson decayed to two muons (two of the green tracks). A W boson candidate decayed to a muon and a neutrino (a green track and purple arrow opposite to it). Other lower energy charged-particles were produced in the collision and are represented as grey tracks. The straighter the track, the more energetic the particle. The red and blue towers in between the dark circles represent energy deposited in DZero calorimeter by the particles created in the collisions. (Click on image for larger version.)
The W and Z bosons are particles that carry the weak force, one of the four fundamental forces found in nature. According to the Standard Model, the W and Z bosons interact with each other due to their weak charge. At Fermilab, we measure the strength of the interaction of the W boson with the Z boson by identifying and studying collisions in which both are produced at the same time. By counting the number of occurrences and measuring the properties
James Degenhardt
(above)and Bing Zhou
(below),both of Univ-
ersity of Michigan, have
worked on this analysis.
Not pictured are Qian
Xu, Michigan, and Tom
Diehl, Fermilab, who
also worked on it.
of the WZ events, we can test the strength of the interaction between the bosons.

W and Z particles are very massive. The W boson weights 85 times the mass of a proton. The Z boson is even heavier. Shortly after they are produced, W and Z bosons disintegrate into lighter types of particles and we detect these "decay products" in the DZero detector. The figure shows one of the DZero candidate events with W and Z bosons produced.

Fermilab's proton-antiproton collider, the Tevatron, is the only particle accelerator in the world that ever could produce both a W and a Z boson
Bing Zhou
in the same collision. DZero scoured approximately 14 trillion collisions produced between April 2002 and June 2004 and found three events with both a W and a Z boson in them. We estimate that processes which look like, but aren't WZ production, will provide us three or more such events 3.5% of the time.

With these three candidate we are able to estimate the rate the Tevatron produces WZ events. Also, we set constraints on the strength of the interaction between the W and Z bosons.

Oana Boeriu,University of Notre Dame, (left) and Greg Davis, Northwestern University, have made important contributions to DZero's Fiber tracker which was used for this and other analyses. They are pictured with a key element of the fiber tracker readout. (Click on image for larger version.)
Result of the Week Archive

Fermilab Water Pressure Adjustments
FESS/Operations will be adjusting the Main Site Domestic Water Pressure to expected Warrenville levels for data collection today. Please notify your Building Manager or Work Central at x3434 of any water pressure related problems.

Free Introductory Tai Chi Class
A free introductory Tai Chi class will be offered in the Recreation Facility on Friday, February 18 from 6:30 AM to 7:15 AM. Registration for the free class can be made by calling the Recreation Office at x5427 or x2548. You must pre-register. You do not need to be a member of the Recreation Facility for this introductory class, however, you will need one to participate in the scheduled 8-week session.

Fermilab Offers Family Open House, Sunday, Feb. 13, 2005
Today Last Day to Register!
From historical scientists to hands-on activities, from an accelerator tour to a liquid-nitrogen show, the Family Open House on Sunday, February 13 from 1:00 p.m. to 4:00 p.m. at Fermilab offers something for the entire family. Visitors need to register by February 10 to receive free tickets. To register, please send an email to edreg@fnal.gov or call Nancy Lanning at 630-840-5588. All are welcome, but the Open House activities will be most appropriate for students age 11 and up.
more information

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