Messung des D*-Meson-Produktionsquerschnitts in tiefinelastischer Streuung mit dem H1-Experiment

Abstract

A cross-section measurement of the production of D* mesons in deep inelastic scattering at a centre-of-mass energy of 319 GeV is presented. The explored kinematic region extends in momentum transfer squared from 5 GeV2 to 100 GeV2 and in inelasticity 0.05 < y < 0.6. D* mesons are detected above a minimal transverse momentum of 1.5 GeV and in the pseudorapidity range |η| < 1.5. The analysed data were recorded in the year 2004-2006 after the upgrade of the HERA accelerator corresponding to an integrated luminosity of 222 pb−1, which is four times more statistics in comparison to the previous H1 measurement. The higher statistics facilitates a better understanding of the sources of systematic errors. Among other things, this leads to a better description of the signal shape and therefore to a smaller systematic error for the signal extraction. Furthermore, due to the higher statistics the single and double differential productions cross section can be investigated using a finer granularity. The production cross sections are compared to the next-to-leading order calculation HVQDIS and the leading order Monte Carlo generators RAPGAP and CASCADE. In general both the Monte Carlo generators and the HVQDIS calculation are able to describe the measurement. However, the decription by the HVQDIS calculation is not as good as by the Monte Carlo predictions, in particular revealing a small discrepancy in the pseudorapidity distribution at η > 0.5.