Thesis: K. Hoffman
Advisor: D. Bortoletto

Title:The Search for Physics Beyond the Standard Model in the b bbar spectrum 
observed in Tevatron proton anti-proton Collisions
                 
Abstract: Many extension have been proposed to the Standard Model of 
fundamental particles and interactions, therefore we have conducted a general 
search with the Colldier Detector at Fermilab (CDF) for particles which would
be expected to appear as a resonance in the b bbar mass spectrum produced in
proton anti-proton collisions at a center of mass energy of 1.8 TeV at  the
Fermilab Tevatron collider. We use 87.3 pb-1 of data collected from 1993-1995 
during collider Run 1b to reconstruct the b bbar mass spectrum from 150-625
GeV/c**2. The spectrum is found to be in good agreement with simulation of
direct b bbar prroduction, and it is therefore used to set limits on the cross
section for resonances decaying with a natural width that is narrower than the
CDF b bbar mass resolution, which excludes the color octect technirho predicted
in walking technicolor theories between 350 and 440 GeV/c**2. in addition we
exclude topgluons, predicted in models of topcolor assisted technicolor, of 
width Gamma=0.3 M in the mass range 280<M<670 GeV/c**2, of width Gamma=0.5M
in the mass range 340<M<640 GeV/c**2 and of width Gamma=0.7 M in the mass range
375<M<560 GeV/c**2. 



Posted to /cdf/pub/thesis/cdf4727_search_bb_spectrum.ps
    http://www-cdf.fnal.gov/thesis/cdf4727_search_bb_spectrum.ps
(This is revision # 1.)

Posted by daniela@cdfsga