Studies of various aspects of the proton structure in deep inelastic scattering at HERA and identification of quark and gluon jets

摘要

This thesis is based on work done as a member of the H1 detector collaboration at DESY during 1989-1994 and consists of three main topics. The possibility to probe the predicted intrinsic charm component in the proton by deep inelastic scattering is investigated in a simulation study, including HERA and a fixed target experiment. For existing experiments the predicted statistics are relatively small, but may still contribute to a solution of the issue. A determination of the gluon density has been obtained in the region 5x10(sup -3) < x < 8x10(sup -2) by measuring the cross section of photon gluon fusion in deep inelastic scattering with the H1 detector at the ep-collider HERA. This direct measurement of the gluon density was based on an integrated luminosity of 242 nb(sup -1) and was performed in a kinematic region previously not accessible. The problem of identifying jets at LEP and HERA has been studied. The identification was based on jet energies and fragmentation properties, but instead of working with the separation variables directly, these have been used to calculate probabilities for having a gluon (or quark) according to Bayes' theorem. 24 refs, 16 figs. (Atomindex citation 26:027138)