CDF Logo Search for Gluino Pairs Decaying into Sbottom Bottom Exotics Logo
We search for sbottom quarks in events with missing transverse energy and b-jets collected by the CDF Run II experiment at the Tevatron using 156 pb^-1 of data. If in reach of Tevatron energie, gluino pair production is expected to have a significant production cross section. In a scenario where the sbottom is lighter than the gluino, sbottoms could be produced through the decay of gluinos into bottom and sbottom quarks, yielding a rich signature consisting of four b-jets, and two neutralinos from the sbottom decay sbottom --> b LSP. We search for a final state with four b-jets and missing transverse energy from the undetected neutralinos. Several control regions are studied to check the background estimation, and are found to be in good agreement with the data. The signal region is defined by missing E_T > 80 GeV and vetoing the presence of leptons. It is subdivided into exclusive single and inclusive double b-tagged events. For the exclusive single tag, 21 events are observed, which is in agreement with standard model background expectations of 16.4+-3.7 events. Requiring inclusive double b-tag we observe 4 events, where 2.6+-0.7 are expected. Hence, no evidence for gluino pair production with squential decay into sbottom-bottom is observed, and a 95% C.L. exclusion limit is set on the masses of the gluino and sbottom of up to 280 and 240 GeV respectively.


Plots and Tables:

Missing ET Spectra:
Missing ET Spectrum before and after cleanup cuts are applied (117 pb-1 subsample), EPS or GIF.
Missing ET Spectrum of events with lepton(s) (control regions C0 and C2) with exactly one b-tag, EPS or GIF.
Missing ET Spectrum of events with lepton(s) (control regions C0 and C2) with two or more b-tags, EPS or GIF.
Missing ET Spectrum of events without leptons with exactly one b-tag, EPS or GIF.
Missing ET Spectrum of events without leptons with two or more b-tags, EPS or GIF.

Expected and Observed Number of Events:

Cross-Section and Mass Limits:
Gluino 95% CL upper cross section limit as a function of gluino mass for a fix mass difference between gluino and sbottom of 60 GeV/c**2 and LSP mass of 60 GeV/c**2, EPS or GIF.
Gluino 95% CL upper cross section limit as a function of sbottom mass for a fix gluino mass of 240 GeV/c**2 and LSP mass of 60 GeV/c**2, EPS or GIF.
95% CL exclusion contours in the gluino and sbottom mass plane, EPS or GIF.

Page page: http://www-cdf.fnal.gov/physics/exotic/r2a/20040610.bbmet_gluinosbottom/index.html was last updated October 21st, 2004 by Stephan Lammel.
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