Search For Charged Higgs Decays of the Top Quark Using Hadronic Decays of the Tau Lepton

This Letter describes a direct search for charged Higgs boson production in proton-antiproton collisions at sqrt(s)=1.8 TeV recorded by the Collider Detector at Fermilab. Two-Higgs-doublet extensions to the standard model predict the existence of charged Higgs bosons. In such models, the branching fraction for top quarks B(t --> H b --> tau nu b) can be large. This search uses the hadronic decays of the tau lepton in this channel to significantly extend previous limits on charged Higgs production.Comment: 6pages, 4 figures, 1 table; LaTeX; submitted to PR

Measurement of the two-jet differential cross section in p(p)over-bar collisions at root s=1800 GeV

A measurement is presented of the two-jet differential cross section d(3)sigma /dE(T)d eta (1)d eta (2) at center of mass energy roots = 1800 GeV in p (p) over bar collisions. The results are based on an integrated luminosity of 86 pb(-1) collected during 1994 to 1995 by the CDF Collaboration at the Fermilab Tevatron collider. The differential cross section is measured as a function of the transverse energy E-T of a jet in the pseudorapidity region 0.1(1)\<0.7 for four different pseudorapidity bins of a second jet restricted to 0.1<\ eta (2) \<3.0. The results are compared with next-to-leading order QCD calculations determined using the CTEQ4 and MRST sets of parton distribution functions. None of the sets ex.amined in this analysis provides a good description of the data

Search for radiative b-hadron decays in p(p)over-bar collisions at root s=1.8 TeV RID C-1693-2008 RID A-5169-2010 RID E-4473-2011 RID C-2406-2008

We have performed a search for radiative b-hadron decays using events produced in p (p) over bar collisions at roots=1.8 TeV and collected by the Collider Detector at Fermilab. The decays we considered were (B) over bar (0)(d)-->(K) over bar*(0)(-->K(-)pi(+))gamma, (B) over bar (0)(s)-->phi(-->K+K-)gamma, Lambda(b)(0)-->Lambda(-->ppi(-))gamma, and their charge conjugates. Two independent methods to identify photons from such decays were employed. In the first method, the photon was detected in the electromagnetic calorimeter. In the second method, the photon was identified by an electron-positron pair produced through the external photon conversion before the tracking detector volume. By combining the two methods we obtain upper limits on the branching fractions for the (B) over bar (0)(d), (B) over bar (0)(s), and Lambda(b)(0) radiative decays which, at the 95% confidence level, are found to be B((B) over bar (0)(d)-->(K) over bar*(0)gamma)phigamma)Lambdagamma)<1.9x10(-3)