Diffractive Dijets with a Leading Antiproton in p¯p Collisions at s=1800 GeV
Physical Review Letters American Physical Society (APS) 84:22 (2000) 5043-5048
Measurement of azimuthal asymmetries in deep inelastic scattering
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 481:2-4 (2000) 199-212
Abstract:
The distribution of the azimuthal angle for the charged hadrons has been studied in the hadronic centre-of-mass system for neutral current deep inelastic positron-proton scattering with the ZEUS detector at HERA. Measurements of the dependence of the moments of this distribution on the transverse momenta of the charged hadrons are presented. Asymmetries that can be unambiguously attributed to perturbative QCD processes have been observed for the first time. (C) 2000 Elsevier Science B.V.Measurement of inclusive(D(s)(±)) photoproduction at HERA ZEUS collaboration
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 481:2-4 (2000) 213-227
Abstract:
The first measurement of inclusive D(s)(±) photoproduction at HERA has been performed with the ZEUS detector for photon-proton centre-of-mass energies 130 < W < 280GeV. The measured cross section for 3 < p (is perpendicular to)/(D(s)) < 12GeV and |η(D(s))| < 1.5 is σ(ep → D(s)X) = 3.79 ± 0.59(stat.) -0.46/+0.26 (syst.) ± 0.94(br.)nb, where the last error arises from the uncertainty in the D(s)(±) decay branching ratio. The measurements are compared with inclusive D*(±) photoproduction cross sections in the same kinematic region and with QCD calculations. The D(s)(±) cross sections lie above a fixed-order next-to-leading order calculation and agree better with a tree-level O(αα(s)/3) calculation that was tuned to describe the ZEUS D*(±) cross sections. The ratio of D(s)(±) to D*(±) cross sections is 0.41 ± 0.07 (stat.) -0.05/+0.03 (syst.) ± 0.10(br.). From this ratio, the strangeness-suppression factor in charm photoproduction, within the LUND string fragmentation model, has been calculated to be γ(s) = 0.27 ± 0.05 ± 0.07(br.). The cross-section ratio and γ(s) are in good agreement with those obtained in charm production in e+e- annihilation. (C) 2000 Elsevier Science B.V.Measurement of the differential dijet mass cross section in pp¯ collisions at s=1.8 TeV
Physical Review D American Physical Society (APS) 61:9 (2000) 091101
Measuring CP violation and B0s-B̄0s mixing using B0s → J/ψφ with φ → K+K-, J/ψ → μ+μ-
Journal of Physics G Nuclear and Particle Physics 26:5 (2000) 741-743