A super solution to
a massive problem

Upper limits on neutral SUSY-Higgs boson production rates as a function of Higgs boson mass. Results are shown for bH associated production and for both H → ττ and H → bb decays.

The Standard Model, a modern theory of elementary particles and their interactions, has had a "massive" problem for many years. It desperately needs a physical mechanism to explain the origin of particle masses. The easiest solution (using just one Higgs boson) is looking a bit worrisome because it may not be able to maintain consistency over a vast range of precision measurements and theoretical predictions. Fortunately, another theory called Supersymmetry (or SUSY) might provide some welcome relief.

The Standard Model arises from symmetries in nature that lead to conservation laws (eg, conservation of energy or momentum). SUSY introduces a new symmetry between fermions and bosons that predicts several new particles, including five Higgs bosons (three neutral, two charged). These new particles would give the Standard Model much more leeway to maintain agreement with existing measurements, while still generating the much-needed particle masses. Furthermore, SUSY predicts that the neutral Higgs bosons could be produced along with b-quarks at a rate observable at the Tevatron collider.

The neutral SUSY-Higgs particles themselves usually decay into pairs of b-quarks or tau-leptons. Although final states with at least three b-quarks have been extensively explored at the Tevatron (Result of the Week, April 14, 2005), the case of SUSY-Higgs bosons produced with b-quarks and decaying into tau-leptons has never before been studied. The DZero collaboration has recently pioneered such a search, requiring one tau to decay hadronically and the other into a muon. The search results were consistent with the expectations from Standard Model backgrounds, and an upper limit on the production rate of neutral SUSY-Higgs bosons was set.

By combining the limits from the bH→bττ (where "τ" stands for "tau") and b(b)H→(b)bb final states and the limit of inclusive H → ττ production (ROW May 11, 2006), DZero has significantly extended the limits on possible SUSY parameters. As data pours in from the Tevatron each day, you can rest assured that DZero is keeping a close eye out for a supersymmetric solution for the Standard Model's "massive" problem.

November 24 - 29
- Four stores provided 95 hours and 42 minutes of luminosity
- CHL had cold box problems
- Recycler had instrumentation problems
- Un-established store lost due to TeV dipole power supply failure
- TeV A1 cryo system had vacuum trouble
- MI-20 fire alarm caused by lighting ballast failure - stash of antiprotons lost

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

Benefits enrollment ends soon
Have you completed your 2007 flexible spending account enrollment? Enrollment ends today, November 30. This is your opportunity to put aside pre-tax dollars for eligible healthcare and dependent care expenses. Enrollment materials are available on the Benefits Department web page or in the Benefits Office.

International Folk Dancing
International Folk Dancing will meet today, November 30, at Kuhn Barn. Dancing begins at 7:30 p.m. with teaching and children's dances 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.

English country dancing
English country dancing will meet at 2 p.m. Sunday, December 3, at Kuhn Barn. Newcomers are most welcome and you don't need to come with a partner. The group will continue meeting the first Sunday afternoon of the month. For more information please contact folkdance@fnal.gov or call 630-584-0825 or 630-840-8194.

Upcoming Activities