Study of Jet Shapes in Charm Photoproduction at HERA

Reference M. Martisikova, presented at DIS 2005, Spring 2005
Document Conference paper or talk
Figures  (1a)  (1b)  (2a)  (2b)  (3)  (4)  (5a)  (5b)  (6)  (7a)  (7b)  (8)
Contact M. Martisikova
Abstract Charm dijet events are investigated in the photoproduction kinematic range in $ep$ collisions at HERA. The data were collected with the H1 Experiment in the years 1999-2000 at a centre-of-mass energy of 318 GeV and correspond to an integrated luminosity of 48 pb-1. One jet is tagged by a muon as being initiated by a charm quark. In order to shed light on the production mechanism of charm events in $ep$ collisions the shape of the other jet is studied to distinguish if it is initiated by a quark or a gluon. The jet shapes are measured as function of kinematic variables such as the transverse momentum, energy and pseudorapidity of the jet and the quantity x_\gamma^{obs}. The shapes are found to be well described by the leading order plus parton shower Monte Carlo simulation PYTHIA in the region of large x_\gamma^{obs}, where according to the simulation the jets are dominantly charm quark initiated. Deviations between data and PYTHIA are observed for small x_\gamma^{obs}, where resolved photon events are expected to contribute significantly and more gluon jets are expected. No such deviations are observed in a dijet photoproduction sample without muon requirements, which is dominated by light quark production.
Links back to overview listing     Locked H1 internal information