arXiv subjects

Martin Erdmann

Publications and source records attributed to Martin Erdmann.

42 records · Page 3Linked to original sources

arXiv2001

Proton and Photon Structure

The increasing precision of the measurements on the proton structure and an improved treatment of the correlated systematic experimental errors constitute a major step forward in our understanding of the flavour decomposition of the proton and the momentum distributions of the various flavours. Together with theoretical progress on the next-to-next-to-leading order QCD corrections to deep inelastic scattering processes, the proton measurements already imply a new level of precision for the strong coupling constant alpha-s. The progress in the measurements on the quantum fluctuations of the photon allows questions on the universal properties of hadronic structures to be addressed.

hep-ex↗

arXiv2001

Investigation of Quark-Antiquark Interaction Properties using Leading Particle Measurements in e+e- Annihilation

Measurements of heavy quark production in electron-positron collisions are used to analyse the strong interactions between quarks and anti-quarks. A scaling behaviour is observed in distributions of the rapidity change of D*, B*, and B mesons. From these distributions information is obtained on the hadron formation time, effective quark masses, and the potential between quark-antiquark pairs. Predictions for fragmentation functions are presented.

hep-ex↗

arXiv2000

Hadronic Structure Functions

Experimental results on hadronic structures are discussed in view of our physics understanding. Achievements and challenges are noted.

hep-ex↗

arXiv2000

On the Structure of the Proton, the Photon, and Colour Singlet Exchange

Structure function measurements of the proton, the photon, and of colour singlet exchange are analysed using fits based on logarithmic Q**2-dependence. The fits reveal the x-dependencies of the hadronic structures and the interaction dynamics as directed by the data.

hep-ex↗

arXiv1999

Diffraction and Low-Q^2 Physics Including Two-Photon Physics

Recent experimental results on the partonic structure of the photon and on the color singlet exchange in strong interaction processes are reviewed. At the LEP electron-positron and HERA lepton-proton colliders, complementary and consistent measurements have been achieved on the quark-gluon structure of quasi-real and virtual photons. At the HERA lepton-proton and Tevatron proton-antiproton colliders, the quark-gluon configuration of the diffractive exchange is consistently found to have a large gluon component. The rate of diffractive interactions observed by the HERA and Tevatron experiments, however, is largely different and challenges explanation (invited plenary talk at the XXIX International Conference on High Energy Physics, Vancouver, B.C. Canada (1998)).

hep-ex↗

arXiv1996

Jets and High-Et Phenomena

The working group on jets and high-Et phenomena of the Future physics at HERA Workshop studied subjects ranging from next-to-leading order (NLO) corrections in deeply inelastic scattering (DIS) and photoproduction with the corresponding determinations of physical quantities, to the physics of instanton-induced processes, where a novel non-perturbative manifestation of QCD could be observed. Other centres of interest were the physics of the forward direction, the tuning of event generators and the development of a new generator which includes a consistent treatment of the small- and large-$x$ QCD evolution. The recommendations of the working group concerning detector upgrades and machine luminosity are summarized.

hep-ph↗