Thursday, March 17
Happy St. Patrick's Day!
2:30 p.m. Theoretical Physics Seminar - Curia II
Speaker: C. Oleari, Universita Milano
Title: QCD Corrections to Higgs Boson Production: Signal and Backgrounds
3:30 p.m. DIRECTOR'S COFFEE BREAK - 2nd Flr X-Over
4:00 p.m. Accelerator Physics and Technology Seminar - 1 West
Speaker: S. Schreiber, DESY
Title: TTF VUV FEL Commissioning
Friday, March 18
3:30 p.m. DIRECTOR'S COFFEE BREAK - 2nd Flr X-Over
4:00 p.m. Joint Experimental Theoretical Physics Seminar - 1 West
Speaker: D. Zieminska, Indiana University
Title: Lifetime Difference and A Limit on Mixing in the
Bs System from DZero
Sunday, March 20
2:30 p.m. Gallery Chamber Series - 2nd Flr X-Over
Rembrandt Chamber Players
Tickets: $15
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Thursday, March 17
Tomato Florentine Soup
Grilled Chicken Cordon Bleu Sandwich $4.75
Chimichangas $3.75
Chicken Marsala $3.75
Maryland Crab Salad $4.75
Italian Sausage Calzones $3.25
SW Chicken Salad with Roasted Corn Salsa $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
is now open. Call x4512 to make your
reservation.
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Flickering at Aspen East
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Aspen East in the Village. (Click on image for larger version.) |
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For some time now, housing employees and residents of the Aspen East Dorm
Facility have reported an eerie, candle-like flickering of the lights. At
times, the phenomenon seemed related to the operation of the copy machine.
Were there ghostly apparitions? Was the house possessed?
FESS/Ops electrical supervisor Rich Bergquist and FESS electrical engineer
Joe Pathiyil found that Aspen East was, indeed, possessed. But the culprits
were the grounded neutral busses in satellite distribution panels and a
compromised neutral connection to the main entry panel from Kuhn Barn.
"There was never any danger," said Bergquist. "But it did take a lot of
man hours to find and repair all of the problems."
FESS/Ops electricians disconnected the incoming power lines from Kuhn Barn
to Aspen East at both ends, then tied them together to create a circuit that
could then be tested. Aspen East power distribution panels were also
inspected. "The neutral bus at the main entry panel is always grounded,"
Pathiyil said. "But grounding neutral busses at satellite panels sets up a
circulating current within the system, causing low voltage current to flow
down the outside of conduits." Pathiyil and Bergquist completed the exorcism
by removing the bonding screws from the satellite panel neutrals.
This left only the question of the copy machine, which did turn out to be
"unbalanced." The problem was solved by redistributing loads from one of the
satellite panels, and the lights now burn brightly at Aspen East.
- Greg Gilbert
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Yesterday's INFN/Fermilab press release listed the wrong affiliation for
Alessio Notari, who is from McGill University.
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FYI: AIP Bulletin of Science Policy News, March 16, 2005
AIP Endorses 7% Increase in DOE Office of Science Budget
The American Institute of Physics and two of its Member Societies have endorsed the Energy Sciences Coalition's FY 2006 Funding Statement for the Department of Energy's Office of Science. The coalition statement calls for a 7%, or $250 million, increase in the Office of Science's budget over the current year.
The Bush Administration's request that was sent to Congress in February
recommended a 2.0% reduction in the total Department of Energy budget.
The Office of Science's budget would be cut further: a 3.8% reduction was
proposed. Under the President's request, the budget for the Office of
Science for the fiscal year starting this October 1 would be 2.0% lower
than it was for FY 2004.
read more
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Studying Matter-AntiMatter Transformations with CDF
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This figure represents an "amplitude scan"
of Delta ms using CDF data.
The data are evaluated in steps of Delta ms.
If the data are not compatible with the particular value of Delta ms,
the expected amplitude (the vertical axis) is zero.
The yellow bands represent the allowed range of the amplitude;
the value of Delta ms where the band first crosses A=1
corresponds to the lower limit on Delta ms. (Click on image for larger version.) |
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Mesons are combinations of a quark and an anti-quark bound
by the strong interaction. Due to the electroweak force,
neutral mesons such as the K0 (strange anti-quark and down
quark), the B0 (bottom anti-quark and down quark) and the
B0s (bottom anti-quark and strange quark) can transform
from particle to antiparticle, e.g., B0s to anti-B0S
(bottom quark and strange anti-quark). These transformations
are refered to as "flavor oscillations" since the quarks
become antiquarks and vice-versa. Measuring the frequency
of these oscillations provides information on fundamental
parameters in the Standard Model of particle physics and may
provide a window to finding physics beyond the Standard
Model.
While flavor oscillations were established in the K0
system in 1960, the first evidence for oscillations in
the B0 system was reported by the ARGUS Collaboration in
1987. The oscillation frequency, Delta md, has since
been measured with a precision approaching 1%. It is known
that B0s mesons oscillate, and since the late 80's,
attempts to measure the oscillation frequency, Delta ms,
have failed. The measurement of Delta ms is one of the most
sought after results at the Tevatron.
The measurement of B0s flavor oscillations requires
exquisite experimental precision to reconstruct the B0s
meson decays, to measure their decay time, and to determine
whether the meson that decayed was produced as a B0s or an
anti-B0s. It is one of the most complex analyses
undertaken by CDF, and it includes many supporting
measurements such as B meson lifetimes and B0 flavor
oscillations. More than 70 physicists (including 24 Ph. D.
students) from 25 institutions are involved, making this one
of the largest coordinated analysis efforts in CDF's
history. The result is shown in the figure above; B0s
flavor oscillations are not observed, and a lower limit on
Delta ms > 7.9 trillion hertz is established. This means
that a B0s meson transforms to a anti-B0s
in less than
0.4 trillionths of a second, at least sixteen times faster
than B0 oscillations. The expected value of Delta ms in
the Standard Model is about 20 trillion hertz. The current
CDF result is not the most restrictive lower limit on Delta
ms, yet with planned improvements and more data to come,
this first result demonstrates that CDF is on the road to
measure Delta ms during Run II.
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Pictured here are 11 of the 24
students actively involved in this Bs
mixing analysis. A complete list of the authors is
available online.
(Click on images for larger version.) |
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Result of the Week Archive
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International Folk Dancing
International Folk Dancing has now moved
back to the Kuhn Barn on Fermilab's site and will
celebrate St. Patrick's Day with some Irish dances
on Thursday, March 17. Dancing begins at 7:30 p.m. with
teaching earlier in the evening and request dancing later on.
Newcomers are welcome and you do not need to come with
a partner. Info at 630-584-0825 or 630-840-8194 or folkdance@fnal.gov.
Upcoming Activities
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