0000000000637079
AUTHOR
P.m. Zerwas
Inelastic photoproduction
Abstract Inelastic photoproduction of J Ψ particles at high energies is one of the processes to determine the gluon distribution in the nucleon. We have calculated the QCD radiative corrections to the color-singlet model of this reaction. They are large at moderate photon energies, but decrease with increasing energies. The cross section and the J Ψ energy spectrum are compared with the available fixed-target photoproduction data and predictions are given for the HERA energy range.
Heavy-quark production in two-photon collisions
Abstract Heavy quarks are copiously produced in two-photon collisions at e + e − colliders. We present the inclusive production rates and the final state distributions of the quarks, including QCD radiative corrections for the leading subprocesses. The results are compared with recent measurements of charmed particle production at PETRA and PEP, and predictions are given for TRISTAN and LEP energies.
Determining Sneutrino Masses and Physical Implications
In some areas of supersymmetry parameter space, sneutrinos are lighter than the charginos and the next-to-lightest neutralino, and they decay into the invisible neutrino plus lightest-neutralino channel with probability one. In such a scenario they can be searched for in decays of charginos that are pair-produced in e+e- collisions, and in associated sneutrino-chargino production in photon-electron collisions. The sneutrino properties can be determined with high accuracy from the edges of the decay energy spectra in the first case and from threshold scans in the second. In the final part of the report we investigate the mass difference of sneutrinos and charged sleptons between the third an…
Gluon fragmentation to gluonium
The fragmentation of gluons to gluonium states is analyzed qualitatively in the non-perturbative region. The convolution of this mechanism with perturbative gluon radiation leaves us with a hard component in the fragmentation of gluon to gluonium.
Supersymmetry parameter analysis: SPA convention and project.
18 páginas, 6 figuras, 12 tablas.-- et al.