arXiv subjects

Thierry Gousset

Publications and source records attributed to Thierry Gousset.

21 records · Page 2Linked to original sources

arXiv1998

Exclusive electroproduction of vector mesons and transversity distributions

We show that the leading twist contribution to exclusive electroproduction of transversely polarized vector mesons vanishes at all orders in perturbation theory. Therefore one cannot extract information on the quark transversity distribution of the nucleon from this reaction. In turn one has that the produced vector meson is purely longitudinal in the large-Q^2 limit, which provides a new test of the dominance of leading twist at finite Q^2.

hep-ph↗

arXiv1996

High-energy exclusive leptoproduction of vector mesons

The physics of diffractive vector meson production in virtual photon nucleon scattering at NMC energies is reviewed. A particular attention is paid to the physical aspects of the reaction and how they influence the observables. The reaction is a good probe to investigate both soft exchange mechanisms and hadronic wave functions. Extension to either HERA or ELFE kinematics is sketched out.

hep-ph↗

arXiv1995

Hard Exclusive Scattering in QCD

We review the theory of hard exclusive scattering in Quantum Chromodynamics. After recalling the classical counting rules which describe the leading scale dependence of form factors and elastic reactions at fixed angle, the pedagogical example of the pion form factor is developped in some detail in order to show explicitely what factorization means in the QCD framework. The inclusion of transverse degrees of freedom leads to the discussion of Sudakov effects which are crucial for protecting the calculation from dangerous infrared regions. The picture generalizes to many hard reactions; a strategy to extract distribution amplitudes from future data is sketched. We discuss also the particular case of hadron-hadron collisions where the independent scattering mechanism dominates asymptotically and where a different factorization formula applies. We briefly present the concepts of color transparency and nuclear filtering and critically discuss the few present data on this subject.

hep-ph↗