Eur. Phys. J. A (2007) 31: 373-381
https://doi.org/10.1140/epja/i2007-10003-9

Regular Article - Hadron Physics

Semi-Inclusive Deep Inelastic Scattering processes from small to large P_T

Dipartimento di Fisica Teorica, Università di Torino and INFN, Sezione di Torino, Via P. Giuria 1, I-10125, Torino, Italy

^* e-mail: mauro.anselmino@to.infn.it

Received: 9 February 2007
Accepted: 24 February 2007
Published online: 27 March 2007

Abstract

We consider the azimuthal and P_T-dependence of hadrons produced in unpolarized Semi-Inclusive Deep Inelastic Scattering (SIDIS) processes, within the factorized QCD parton model. It is shown that at small P_T values, P _T ≲ 1GeV/c, lowest-order contributions, coupled to unintegrated (transverse-momentum-dependent) quark distribution and fragmentation functions, describe all data. At larger P_T values, P _T ≳ 1GeV/c, the usual pQCD higher-order collinear contributions dominate. Having explained the full P_T range of available data, we give new detailed predictions concerning the azimuthal and P_T-dependence of hadrons which could be measured in ongoing or planned experiments by HERMES, COMPASS and JLab Collaborations.