Fermilab TodayThursday, April 29, 2004  
Thursday, April 29
2:30 p.m. Theoretical Physics Seminar - Curia II
Speaker: G. Weiglein, University of Durham
Title: Higgs and SUSY and Present and Future Colliders
3:30 p.m. DIRECTOR'S COFFEE BREAK - 2nd Flr X-Over
4:00 p.m. Accelerator Physics and Technology Seminar - 1 West
Speaker: E. Gianfelice-Wendt, DESY
Title: The Lepton Beam Polarisation in the Frame of the Hera Luminosity Upgrade

Friday, April 30
3:30 p.m. DIRECTOR'S COFFEE BREAK - 2nd Flr X-Over
4:00 p.m. Joint Experimental Theoretical Physics Seminar - 1 West
Speaker: S. Burdin, Fermilab
Title: B+/B0 Lifetime Ratio and Bd Mixing at D0

Wilson Hall Cafe
Thursday, April 29
Sante Fe Black Bean soup
Marinara Meatball Sub $4.75
Butter Crumb Baked Fish $4.75
Pork Chop Teriyaki $3.75
Bake Ham & Swiss on a Ciabatta Roll $4.75
Sausage & Sweet Onions Strombolis $2.75
Crispy Fried Chicken Ranch Salad $4.75
Wilson Hall Cafe Menu
Chez Leon
Weather Chance T-Storms 79º/55º

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In Memoriam: Ronald Walker
Ronald Walker
Ronald Walker
Ronald Walker, a Fermilab physicist of 32 years and Deputy Cryogenic Department Head, died on Monday, April 26 at his home in Naperville.

Walker started his physics career at Fermilab in 1972 working on the 30-inch bubble chamber physics experiment. Accelerator Division Head Roger Dixon, who was a graduate student at Purdue University at the time, spent his first days at Fermilab working for Walker on the camera system for the 30-inch bubble chamber. "I was just getting used to the whole field then, and ever since, I felt a very special connection to Ron," Dixon said. "He made a big impression on me. It was quite an exciting time at the lab, and Ron was one of the people who showed me there was something to be excited about."

Walker went on to work on the 15-foot bubble chamber and then moved to the Accelerator Division's Cryogenic Department, where he became the Deputy Cryogenic Department Head in 1990. Jay Theilacker, Cryogenic Department Head, describes Walker as a staple in the Cryogenic Department. Walker was instrumental in the design, installation and commissioning of the Central Helium Liquefier used to cool the Tevatron. Twenty years after its commissioning, Fermilab's CHL remains the world's largest helium liquefier. In 1984, Walker received an Industrial Research Award for his development of a helium gas analyzer. "Ron was the one physicist in our department who always brought a different perspective to the table and came up with unique solutions," Theilacker said. "This was a huge benefit that is going to be difficult to replace."

Visitation will be on Friday, April 30 from 4:00 p.m. to 9:00 p.m. at the Beidelman-Kunsch Funeral Home, 516 S. Washington in Naperville (630) 355-0264.

Accelerator Update
April 26 - April 28
- Although Operations established one store during this time period, it wasn't useful beam. The existing store provided approximately 28 hours and 50 minutes of luminosity to the experiments.
- Core emittance problems plague the TeV, Pbar, and the Recycler
- Experts conducted many studies in the TeV, Main Injector, and Booster
- TeV sector A1 cold compressor failed early Wednesday morning

View the current accelerator update
View the Tevatron Luminosity Charts

In the News
From the Detroit Free Press, April 28, 2004:
Beyond tiny, neutrinos loom as a big mystery
By Robert Boyd
WASHINGTON -- You can't see them. You can't feel them. But every second, trillions of them flit harmlessly through your body.

They are neutrinos, tiny ghostlike specks of matter that played -- and still play -- an essential role in the evolution and life of the universe.

"If there were no neutrinos, the sun and the stars wouldn't shine," said Boris Kayser, a researcher at the Fermi National Accelerator Laboratory in Batavia, Ill. "There would be no Earth, no moon, no us. Without them, we wouldn't be here."
read more

Fermilab Result of the Week
DZero B- and B0 Decays Get the Chance of a Lifetime
We measure the ratio of lifetimes by taking the ratio of the number of events, in samples which are dominated by neutral and charged B mesons, as a function of time. If the two lifetimes were the same, the data points in the above histogram would fall on a flat line. (Click on image for larger version.)
A B-meson consists of a bottom quark and an anti-quark of another type. The lightest members of the B-family are B- (b-ubar) and B0 (b-dbar) and they disintegrate (or decay) in about a trillionth of a second. Naively the B- and B0 mesons are expected to have the same lifetime but a small difference has been measured previously. This is due to slightly different interactions between heavy and light quarks in charged and neutral B mesons.

Recent theoretical developments allow us to predict the ratio of these lifetimes with more precision than previously possible. Therefore it
Jadwiga Warchol
(University of Notre
Dame) works on the
Central Fiber Tracker
which played an
important role in this
is very important to improve the precision of experimental measurements in order to test the theoretical models. In Run II, the DZero experiment has collected a large sample of B- and B0 decays and has made a precision measurement of this difference using decays of B mesons to a muon, its neutrino and a D meson (which contains a charm quark).

Our preliminary result (R = 1.093 +- 0.021 (stat) +- 0.022 (sys)) agrees with previous results, and the precision of our measurement is as good as the previous single best measurement (from the Belle experiment at KEK and BaBar experiment at SLAC). We are collecting more data with which to further improve the precision of this important measurement.

Sergey Burdin (left) and Andrei Nomerotski (right) (both of FNAL) and Guennadi Borissov (not pictured) (Univ.Lancaster) have been working on measuring B-Lifetime Ratios. (Click on image for larger version.)

Result of the Week Archive

New Book Purchase Suggestion Lists
New Book purchase suggestion lists for the week of April 27 are now available online. These include Majors book lists in four subject areas. There is also an Amazon suggestion list in the form of a shopping cart, viewable by entering the password "library."

Fermilab Picnic and Cougar Game
The Fermilab Picnic and Cougar game will be on July 10. The deadline to purchase tickets is May 28. The picnic will begin at 4:00 PM under the Fermilab tent at the Kane County Cougar Stadium and run until 6:00 p.m. The game with reserved seating begins at 6:00 p.m. The cost for the whole event is only $12.00 per person, which includes your reserved game ticket and all-you-can-eat buffet Registration forms can be found in the Recreation Newsletter, the Recreation Office, and the Users Office. For further information pick up a registration form or contact the Recreation Office, X2548 or X5427.

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