Properties of photon plus two-jet events in p¯p collisions at √s=1.8 TeV
Physical Review D Particles Fields Gravitation and Cosmology 57:1 (1998) 67-77
Abstract:
We present the first general measurements (invariant-mass, transverse-energy, and angular distributions) of the process, (Formula presented) (Formula presented) using data collected by the CDF at Fermilab. We compare the data with predictions from a tree-level QCD calculation and the PYTHIA shower Monte Carlo program. Our data sample is particularly sensitive to contributions from initial- and final-state radiation of photons and jets. Using the PYTHIA Monte Carlo program, we contrast the kinematical distributions for direct photon production with those for initial- and final-state photon radiation (bremsstrahlung). Based on the angular distributions, we find that our data favor a mixture of bremsstrahlung and direct photon production, as predicted, over either process alone. © 1998 The American Physical Society.Radiative decay modes of the D0 meson
Physical Review D Particles Fields Gravitation and Cosmology 58:9 (1998) 920011-920016
Search for first generation scalar leptoquark pairs in pp collisions at √ s = 1.8 TeV
Physical Review Letters 80:10 (1998) 2051-2056
Abstract:
We have searched for first generation scalar leptoquark (LQ) pairs in the ev + jets channel using pp collider data (∫L dt ≈ 115pb-1) collected by the D0 experiment at the Fermilab Tevatron during 1992-1996. The analysis yields no candidate events. We combine the results with those from the ee + jets vv + jets channels to obtain 95% confidence level (C.L.) upper limits on the LQ pair production cross section as a function of mass and of β, the branching fraction to a charged lepton. Comparing with the next-to-leading order theory, we set 95% C.L. lower limits on the LQ mass of 225, 204, and 79 GeV/c2 for β = 1, 1/2, and 0, respectively. © 1998 The American Physical Society.Search for flavor-changing neutral current decays of the top quark in pp collisions at √s = 1.8 TeV
Physical Review Letters 80:12 (1998) 2525-2530
Abstract:
We search for the flavor-changing neutral current decays of the top quark t → λ and t → qZ (here represents the c and u quarks) in pp collisions at √s = 1.8 TeV. We use a dataset (∫ L dt˜ 110pb-1) collected during the 1992-1995 run of the Collider Detector at Fermilab. We set 95% confidence level limits on the branching fractions B(t → qλ) < 3.2% and B(t → qZ) < 33%, consistent with the standard model. © 1998 The American Physical Society.Search for heavy pointlike dirac monopoles
Physical Review Letters 81:3 (1998) 524-529