Search for the supersymmetric partner of the top quark in dilepton events from pp collisions at square root of s=1.8 TeV.
Phys Rev Lett 90:25 Pt 1 (2003) 251801
Abstract:
We have searched for pair production of the supersymmetric partner of the top quark (stop) in 107 pb(-1) of pp collisions at square root of s=1.8 TeV collected by the Collider Detector at Fermilab (CDF). Each stop is assumed to decay into a lepton, bottom quark, and supersymmetric neutrino. Such a scenario would give rise to events with two leptons, two hadronic jets, and a substantial imbalance of transverse energy. No evidence of such a stop signal has been found. We exclude stop masses in the region (80=m(t)=135 GeV/c(2)) in the mass plane of stop versus sneutrino.Erratum: Measurement of the tt̄ production cross in pp̄ collisions at √s= 1.8 Tev (Physical Review D (2001) 64 (32002))
Physical Review D - Particles, Fields, Gravitation and Cosmology 67:11 (2003) 1199011-1199012
Search for a W' boson decaying to a top and bottom quark pair in 1.8 TeV pp collisions.
Phys Rev Lett 90:8 (2003) 081802
Abstract:
We report the results of a search for a W' boson produced in pp; collisions at a center-of-mass energy of 1.8 TeV using a 106 pb(-1) data sample recorded by the Collider Detector at Fermilab. We observe no significant excess of events above background for a W' boson decaying to a top and bottom quark pair. In a model where this boson would mediate interactions involving a massive right-handed neutrino (nu(R)) and have standard model strength couplings, we use these data to exclude a W' boson with mass between 225 and 536 GeV/c(2) at 95% confidence level for M(W')>>M(nu(R)) and between 225 and 566 GeV/c(2) at 95% confidence level for M(W')Momentum distribution of charged particles in jets in dijet events in pp collisions at √s=1.8 TeV and comparisons to perturbative QCD predictions
Physical Review D 68:1 (2003)
Abstract:
Inclusive momentum distributions of charged particles in restricted cones around jet axes were measured in dijet events with invariant dijet masses in the range 80 to 600 GeV/c2. Events were produced at the Fermilab Tevatron in pp collisions with a center of mass energy of 1.8 TeV and recorded by the Collider Detector at Fermilab. The results were compared to perturbative QCD calculations carried out in the framework of the modified leading log approximation (MLLA) and assuming local parton-hadron duality. It was shown that the data follow theoretical predictions quite well over the whole range of the jet energies included in this analysis. We extracted the MLLA cutoff scale Qe f f and found a value of 230±40 MeV. The theoretical prediction of Ejetsin θc scaling, where u c is the cone opening angle, was experimentally observed for the first time. From the MLLA fits to the data, two more parameters were extracted: the ratio of parton multiplicities in gluon and quark jets, r = Npartonsg-jet /Npartonsq-jet = 1.9±0.5, and the ratio of the number of charged hadrons to the number of predicted partons in a jet, KLPHDcharged=Nhadronscharged/Npartons=0.56±0.10.Search for the flavor-changing neutral current decay D0→µ+µ- in pp collisions at √s=1.96 TeV
Physical Review D 68:9 (2003)