Thursday, February 12|
1:30 p.m. Electrical/Electronics Safety Seminar - Curia II
Speaker: D. Robley, Fluke Corporation
Title: Digital Multimeter Safety Training Course:
Learn How to Identify and Avoid Electrical
2:30 p.m Theoretical Physics Seminar - Curia II
Speaker: D. Rainwater, DESY
Title: Higgs Pair Production and the Higgs Potential
3:30 p.m. DIRECTOR'S COFFEE BREAK - 2nd Flr X-Over
THERE WILL BE NO ACCELERATOR PHYSICS AND TECHNOLOGY SEMINAR TODAY
Friday, February 13
3:30 p.m. Wine & Cheese - 2nd Flr X-Over
THERE WILL BE NO JOINT EXPERIMENTAL THEORETICAL
PHYSICS SEMINAR THIS WEEK
Thursday, February 12|
Old Fashioned Tomato soup
Chicken parmigana w/pasta and marinara $3.50
Assorted gourmet sandwiches and panini $4.75
Baked tilapia w/a pineapple chipotle sauce and coconut cous cous $3.50
1/2 pound burger w/bacon, Thousand Island and pickles on grilled
Rustic chicken salad over wild greens w/fresh fruit $3.75
Eurest Dining Center Weekly Menu
Fermilab Wins Two Environmental Awards|
The DOE's Office of Science recently announced that
Fermilab won two 2003 Pollution Prevention and Environmental
Stewardship Accomplishment awards.
|Battery in the under-|
carriage of one of the
With an increase in the number of alternative-fuel vehicles
and the installation of on-site refueling facilities, Fermilab saved
over 10,000 gallons of petroleum in FY03. The Office of Science recognized
George N. Davidson, Jeffrey W. Irvin, Gregory B. Mitchell, Brian
K. Niesman, Randall G. Ortgiesen, and Jeffrey A. Sims for their
commitment to the Fermilab Alternative Fuel Initiative.
Jose De La O, Anna Pla-Dalmau, Dale R. Wilderspin, Scott K. Borton, John J. Kelly, and Eric McHugh were recognized for their efforts in the Scintillator Plastic Recycling Program. The Plastic Scintillator Extrusion Line, installed in the spring of 2003, produces 3,000-6,000 pounds of waste a month. These workers recognized the problem and found a local vendor that could accept 100% of the waste plastic. Amy Pavnica, chair of Fermilab's Environmental Protection Subcommittee, calls this an example of "good old-fashioned recycling."
The honorees will be officially recognized at an awards ceremony in the Spring.
The Plastic Scintillator Extrusion Line (Click on image for larger version.)|
February 9 - February 11|
- Operations established one store during this period. That store
along with an existing store, provided approximately 44 hours and
3 minutes of luminosity to the
- The I- Source suffered from sparking and trips
- Recycler took transfers of antiprotons
View the current accelerator update
View the Tevatron Luminosity Charts
From Nature, February 12, 2004|
Particle physics: Lattice window on strong force
By Ian Shipsey
A long-awaited breakthrough has been made in lattice quantum chromodynamics — a means of calculating the effect of the strong force between sub-atomic particles that could, ultimately, unveil new physics.
The fundamental particles called quarks exist in atom-like bound states,
such as protons and neutrons, that are held together by the strong force.
The heavier varieties of quark, such as the bottom quark, can disintegrate
to produce other, lighter particles, and the pattern of the decay rates is
constrained, but not determined, in the theory of fundamental particles,
the standard model. That pattern, especially the part involving the bottom
quark, is sensitive to new physical phenomena. But although accurate
measurements of the rates have been made, the window on new physics
has been obscured. This is because the binding effect of the strong
force between quarks modifies the decay rates: unless correction factors
can be accurately worked out, the data cannot be fully interpreted for
signs of any physics that is as yet unknown. This has been the case for
almost 40 years. But at last, Davies et al. report an advance in lattice
quantum chromodynamics, a method of calculating the effect of the strong
force, that promises the calculational precision required (C. T. H. Davies
et al. Phys. Rev. Lett. 92, 022001; 2004).
26 Theorists + Computer Clusters = Progress|
in Lattice QCD
The results of two sets of lattice
calculations divided by experimental measurements. A value
of 1 represents perfect agreement. (Click on image for larger version.)|
Left: The old way of doing lattice QCD yields results that differ
by 10 to 15% from experimental data.
Right: QCD calculations using improved staggered fermions give
correct results for a wide variety of hadrons.
For nearly 30 years, theorists have tried to calculate properties of
particles containing quarks directly from the basic
equations of quantum chromodynamics (QCD). The most promising
approach is called lattice gauge theory, but it requires a
lot of computing power. So, starting in November 2000,
Fermilab's Computing Division began to build clusters of PCs
for lattice QCD. The clusters now contain 512 processors,
which together are about 6 times faster than the lab's special-purpose
ACPMAPS computer built in the 1980s.
Although computers are getting faster, until recently many
theorists continued to use the so-called quenched approximation,
a rather drastic simplification of QCD. Now 26 lattice gauge
theorists-unusually many for a theory paper-have published
evidence that a new method, called improved staggered fermions,
allows them to scrap the quenched approximation, yielding much
better results. Past lattice QCD calculations have agreed with
experimental results within 10 to 15%. Although this is pretty
good, such results are insufficient for precision measurements
obtained by today's experiments. Using the new method, the
26 theorists have achieved agreement with experimental data
for a wide variety of hadrons (see above graphic). Lattice theorists
now begin to make precise predictions of future measurements of
The new lattice-QCD method was devised by Peter Lepage,
at Cornell University, and the MILC Collaboration.
Over the last several years MILC has devoted most of its
computing resources at NSF and DOE supercomputer centers
to calculations using improved staggered fermions.
MILC's long-standing policy has been to make the
fruits of their efforts freely available to other physicists,
including their "competitors." Physicists at Cornell, Glasgow,
and Ohio State have used the algorithms to calculate properties
of hadrons containing bottom quarks, others - including Fermilab
theorists Andreas Kronfeld, Paul Mackenzie, and Jim Simone -
have investigated charmed particles.
Because the full range of results was far more impressive
than any individual one, all 26 theorists joined forces
and wrote one paper. Read a related story in
Nature, which is also featured in today's
issue of Fermilab Today.
|The MILC collaboration
(left to right):(back row) Eric Gregory, Chris Aubin, Bob Sugar, Urs Heller,
Jim Hetrick; (front row) Steve Gottlieb, Claude Bernard, Carleton DeTar, James Osborn,
Doug Toussaint. (Click on image for larger version.)|
(from left to right) Jim Simone, Andreas Kronfeld,
and Paul Mackenzie, in front of Fermilab's first PC cluster for lattice
QCD, installed in the New Muon Lab.
(Click on image for larger version.)|
Physical Review Letters: High-Precision Lattice QCD Confronts Experiment
Nature: Particle physics: Lattice window on strong force
Result of the Week Archive
Fermilab's Gallery Chamber Series|
The Fermilab Gallery Chamber Series will present
the Baroque Trio Sonatas on Sunday, February 29 at 2:30 p.m.
in the 2nd floor art gallery.
Recreation Adult Outing
There will be a recreation adult outing on Saturday,
February 21, 2003 at the Pheasant Run Resort & Spa.
A buffet dinner will be followed by the play, "The
Underpants," by Carl Sternheim; adaptation by Steve
Martin; directed by Karen Kessler. The deadline to
order tickets is January 26. Call or stop by the
Recreation Office x5427, x2548 to pick up a
brochure and registration form.