The ZEUS Leading Proton Spectrometer and its use in the measurement of elastic ρ0 photoproduction at HERA
Zeitschrift für Physik C Particles and Fields Springer Nature 73:2 (1997) 253-268
Abstract:
The differential cross section dσ/dt for elastic ρ0 photoproduction, γp → ρ0p (ρ0 → π+π−), has been measured in ep interactions at HERA. The squared four-momentum exchanged at the proton vertex, t, has been determined directly by measuring the momentum of the scattered proton using the ZEUS Leading Proton Spectrometer (LPS), a large scale system of silicon micro-strip detectors operating close to the HERA proton beam. The LPS allows the measurement of the momentum of high energy protons scattered at small angles with accuracies of 0.4% for the longitudinal momentum and 5 MeV for the transverse momentum. Photoproduction of ρ0 mesons has been investigated in the interval 0.073 < ¦t¦< 0.40 GeV2, for photon virtualities Q2< 1 GeV2 and photon-proton centre-of-mass energies W between 50 and 100 GeV. In the measured range, the t distribution exhibits an exponential shape with a slope parameter b = 9.8 ± 0.8 (stat.) ±1.1 (syst.) GeV−2. The use of the LPS eliminates the contamination from events with diffractive dissociation of the proton into low mass states.Differential cross sections of D*± photoproduction in ep collisions at HERA
Physics Letters Section B Nuclear Elementary Particle and High Energy Physics 401:1-2 (1997) 192-206
Abstract:
Inclusive photoproduction of D*± in ep collisions at HERA has been measured with the ZEUS detector for photon-proton centre of mass energies in the range 115 < W < 280 GeV and photon virtuality Q2 < 4 GeV2. The cross section σ → D*X integrated over the kinematic region pDz.ast;Search for new particles decaying to dijets at CDF
Physical Review D American Physical Society (APS) 55:9 (1997) r5263-r5268
Differential cross sections of D∗± photoproduction in ep collisions at HERA
Physics Letters B Elsevier 401:1-2 (1997) 192-206
Abstract:
Inclusive photoproduction of D∗± in ep collisions at HERA has been measured with the ZEUS detector for photon-proton centre of mass energies in the range 115 < W < 280 GeV and photon virtuality Q2 < 4 GeV2. The cross section σep → D∗x integrated over the kinematic region pƒD∗ > 3 GeV and −1.5 < ηD∗ < 1.0 is (10.6 ± 1.7 (stat.) ±1.31.6 (syst.)) nb. Differential cross sections as functions of pƒD∗, ηD∗ and W are given. The data are compared with two next-to-leading or perturbative QCD predictions. For a calculation using a massive charm scheme the predicted cross sections are smaller than the measured ones. A recent calculation using a massless charm scheme is in agreement with the data.Search for Lepton Flavor Violation in ep Collisions at 300 GeV Center of Mass Energy
ArXiv hep-ex/9704018 (1997)