The ZEUS Leading Proton Spectrometer and its use in the measurement of elastic 蟻0 photoproduction at HERA
Zeitschrift f眉r Physik C Particles and Fields Springer Nature 73:2 (1997) 253-268
Abstract:
The differential cross section d蟽/dt for elastic 蟻0 photoproduction, 纬p 鈫 蟻0p (蟻0 鈫 蟺+蟺鈭), 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 蟻0 mesons has been investigated in the interval 0.073 < 娄t娄< 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 卤 0.8 (stat.) 卤1.1 (syst.) GeV鈭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*卤 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*卤 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 蟽 鈫 D*X integrated over the kinematic region pDz.ast;Differential cross sections of D鈭椔 photoproduction in ep collisions at HERA
Physics Letters B Elsevier 401:1-2 (1997) 192-206
Abstract:
Inclusive photoproduction of D鈭椔 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 蟽ep 鈫 D鈭梮 integrated over the kinematic region p茠D鈭 > 3 GeV and 鈭1.5 < 畏D鈭 < 1.0 is (10.6 卤 1.7 (stat.) 卤1.31.6 (syst.)) nb. Differential cross sections as functions of p茠D鈭, 畏D鈭 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)
Measurement of Elastic $J/蠄$ Photoproduction at HERA
ArXiv hep-ex/9704013 (1997)