Limits on quark-lepton compositeness scales from dileptons produced in 1.8 TeV pp-collisions
Physical Review Letters 79:12 (1997) 2198-2203
Abstract:
The dilepton mass spectrum in pp-→|+|-+X interactions is studied using dielectrons (ee) and dimuons (μμ) in 100 pb- of data collected with the Collider Detector at Fermilab. The data are consistent with standard model predictions. The mass spectrum, being a probe for new physics, is examined for new interactions of quarks and leptons from a common composite structure. Assuming a contact interaction with the conventional coupling g20/4π = 1, limits on chiral quark-electron and quark-muon compositeness scales in the range of 2.5 to 4.2 TeV are obtained. © 1997 The American Physical Society.Measurement of Diffractive Dijet Production at the Fermilab Tevatron
Physical Review Letters 79:14 (1997) 2636-2641
Abstract:
We report the observation and measurement of the rate of diffractive dijet production at the Fermilab Tevatron p¯p collider at √s=1.8TeV. In events with two jets of ET>20GeV, 1.8<|η|<3.5, and η1η2>0, we find that the diffractive to nondiffractive production ratio is RJJ=[0.75±0.05(stat)±0.09(syst)]%. By comparing this result, in combination with our measured rate for diffractive W boson production reported previously, with predictions based on a hard partonic pomeron structure, we determine the pomeron gluon fraction to be fg=0.7±0.2. © 1997 American Physical Society.Properties of jets in W boson events from 1.8 TeV p̄ p collisions
Physical Review Letters 79:24 (1997) 4760-4765
Abstract:
We present a study of events with W bosons and hadronic jets produced in p̄p collisions at a center of mass energy of 1.8 TeV. The data consist of 51 400 W± → e± decay candidates from 108 pb-1 of integrated luminosity collected using the CDF detector at the Fermilab Tevatron Collider. Cross sections and jet production properties have been measured for W + ≥1 to ≥4 jet events. The data are compared to predictions of leading-order QCD matrix element calculations with added gluon radiation and simulated parton fragmentation.Properties of six-jet events with large six-jet mass at the Fermilab proton-antiproton collider
Physical Review D - Particles, Fields, Gravitation and Cosmology 56:5 (1997) 2532-2543
Abstract:
We describe the properties of six-jet events, with the six-jet mass exceeding [Formula presented] produced at the Fermilab proton-antiproton collider operating at a center-of-mass energy of 1.8 TeV. Observed distributions for a set of 20 multijet variables are compared with predictions from the HERWIG QCD parton shower Monte Carlo program, the NJETS leading order QCD matrix element Monte Carlo program, and a phase-space model in which six-jet events are distributed uniformly over the kinematically allowed region of the six-body phase space. In general the QCD predictions provide a good description of the observed six-jet distributions. © 1997 The American Physical Society.Search for charged higgs boson decays of the top quark using hadronic decays of the tau lepton
Physical Review Letters 79:3 (1997) 357-362