Measurement of exclusive ω electroproduction at HERA
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 487:3-4 (2000) 273-288
Abstract:
The exclusive electroproduction of ω mesons, ep → e ω p, has been studied in the kinematic range 3 < Q2 < 20 GeV2, 40 < W < 120 GeV and |t| < 0.6 GeV2 with the ZEUS detector at HERA using an integrated luminosity of 37.7 pb-1. The ω mesons were identified via the decay ω → π+ π- π0. The exclusive cross section in the above kinematic region is σ(ep) → e ω p = 0.108 ± 0.014 (stat.) ± 0.026(syst.) nb. The reaction ep → e φ p, φ → π+ π- π0, has also been measured. The cross sections, as well as the ratios σ γ·p → ωp/σ γ · p → p0p and σ γ · p → ωp/σγ·p → φp, are presented as a function of W and Q2. Thus, for the first time, the properties of ω electroproduction can be compared to those of p0,φ and J/ψ electroproduction at high W. (C) 2000 Elsevier Science B.V.The bb̄ production cross section and angular correlations in pp̄ collisions at √s = 1.8 TeV
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 487:3-4 (2000) 264-272
Abstract:
We present measurements of the bb̄ production cross section and angular correlations using the DO detector at the Fermilab Tevatron pp̄ Collider operating at √s = 1.8 TeV. The b quark production cross section for |y(b)| < 1.0 and p(T)/b > 6 GeV/c is extracted from single muon and dimuon data samples. The results agree in shape with the next-to-leading order QCD calculation of heavy flavor production but are greater than the central values of these predictions. The angular correlations between b and b̄ quarks, measured from the azimuthal opening angle between their decay muons, also agree in shape with the next-to-leading order QCD prediction. (C) 2000 Elsevier Science B.V.Limits on Light Gravitino Production and New Processes with Large Missing Transverse Energy in pp¯ Collisions at s=1.8 TeV
Physical Review Letters American Physical Society (APS) 85:7 (2000) 1378-1383
Limits on quark compositeness from high energy jets in p̄p collisions at 1.8 TeV
Physical Review D Particles Fields Gravitation and Cosmology 62:3 (2000) 1-6
Abstract:
Events in p̄p collisions at √s= 1.8 TeV with total transverse energy exceeding 500 GeV are used to set limits on quark substructure. The data are consistent with next-to-leading order QCD calculations. We set a lower limit of 2.0 TeV at 95% confidence on the energy scale ΛMeasurement of the W Boson Mass with the Collider Detector at Fermilab
ArXiv hep-ex/0007044 (2000)