Measurement of charm fragmentation fractions in photoproduction at HERA
Journal of High Energy Physics 2013:9 (2013)
Abstract:
The production of D 0, D *+, D +, Ds+ and Λc+ charm hadrons and their antiparticles in ep scattering at HERA has been studied with the ZEUS detector, using a total integrated luminosity of 372 pb-1. The fractions of charm quarks hadronising into a particular charm hadron were derived. In addition, the ratio of neutral to charged D-meson production rates, the fraction of charged D mesons produced in a vector state, and the stangeness-suppression factor have been determined. The measurements have been performed in the photoproduction regime. The charm hadrons were reconstructed in the range of transverse momentum p T > 3.8 GeV and pseudorapidity |η| < 1.6. The charm fragmentation fractions are compared to previous results from HERA and from e + e - experiments. The data support the hypothesis that fragmentation is independent of the production process. © 2013 SISSA.Two-Pulse Ionization Injection into Quasi-Linear Laser Wakefields
(2013)
Measurement of D ± production in deep inelastic ep scattering with the ZEUS detector at HERA
Journal of High Energy Physics 2013:5 (2013)
Abstract:
Charm production in deep inelastic ep scattering was measured with the ZEUS detector using an integrated luminosity of 354 pb-1. Charm quarks were identified by reconstructing D± mesons in the D ± → K∓π±π ± decay channel. Lifetime information was used to reduce combinatorial background substantially. Differential cross sections were measured in the kinematic region 5 < Q 2 < 1000 GeV 2, 0.02 < y < 0.7, 1.5 < p T (D ±) < 15 GeV and |η(D ±)| < 1.6, where Q 2 is the photon virtuality, y is the inelasticity, and p T (D ±) and η(D ±) are the transverse momentum and the pseudorapidity of the D ± meson, respectively. Next-to-leading-order QCD predictions are compared to the data. The charm contribution, F2cc̄, to the proton structure-function F 2 was extracted. © 2013 SISSA.Complete Spatial Characterization of an Optical Wavefront Using a Variable-Separation Pinhole Pair
Institute of Electrical and Electronics Engineers (IEEE) (2013) 1-1
Polarization-controlled quasi-phase matching for linearly and circularly polarized high harmonic generation
Institute of Electrical and Electronics Engineers (IEEE) (2013) 1-1