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.Measurement of the cross section and angular correlations for associated production of a Z boson with b hadrons in pp collisions at sqrt(s) = 7 TeV
ArXiv 1310.1349 (2013)
Modification of jet shapes in PbPb collisions at sqrt(s[NN]) = 2.76 TeV
ArXiv 1310.0878 (2013)
Indirect measurement of sin2θw (MW ) using e+e- pairs in the Z-boson region with p̄p collisions at a center-of-momentum energy of 1.96 TeV
Physical Review D - Particles, Fields, Gravitation and Cosmology 88:7 (2013)
Abstract:
Drell-Yan lepton pairs are produced in the process p̄p→e +e-+X through an intermediate γ*/Z boson. The lepton angular distributions are used to provide information on the electroweak-mixing parameter sin2θw via its observable effective-leptonic sin2θw, or sinâ¡2θefflept. A new method to infer sin 2θw or, equivalently, the W-boson mass MW in the on-shell scheme, is developed and tested using a previous CDF Run II measurement of angular distributions from electron pairs in a sample corresponding to 2.1 fb-1 of integrated luminosity from p̄p collisions at a center-of-momentum energy of 1.96 TeV. The value of sinâ¡2θefflept is found to be 0.2328±0.0011. Within a specified context of the standard model, this results in sin 2θw=0.2246±0.0011, which corresponds to a W-boson mass of 80.297±0.055 GeV/c2, in agreement with previous determinations in electron-position collisions and at the Tevatron collider. © 2013 American Physical Society.Erratum: Indirect measurement of sin2θW (MW) using e+e- pairs in the Z-boson region with pp¯ collisions at a center-of-momentum energy of 1.96 TeV [Phys. Rev. D 88, 072002 (2013)]
Physical Review D American Physical Society (APS) 88:7 (2013) 079905