Eur. Phys. J. C (2017) 77: 744
https://doi.org/10.1140/epjc/s10052-017-5323-6

Regular Article - Theoretical Physics

QCD leading order study of the leptoproduction at HERA within the nonrelativistic QCD framework

¹ School of Science, Guizhou Minzu University, Guiyang, 550025, People’s Republic of China
² Department of Physics, School of Biomedical Engineering, Third Military Medical University, Chongqing, 400038, People’s Republic of China

^* e-mail: hfzhang@ihep.ac.cn

Received: 21 July 2017
Accepted: 20 October 2017
Published online: 7 November 2017

Abstract

As indicated in our previous paper (Zhang and Sun in Phys. Rev. D 96:034002, 2017), the existing literature studying the production in deeply inelastic scattering (DIS) in collinear factorisation is on the basis of a formalism that will lead to wrong results when the ranges of the transverse momentum or the rapidity of the in the laboratory frame do not cover all values possible for them. In this paper, we present the renewed results for the production in DIS at HERA within the nonrelativistic QCD framework at QCD leading order (LO). Three different sets of the long-distance matrix elements are employed for comparison. The predictions via the colour-singlet (CS) model at QCD LO are generally below the experimental data especially in the regions where perturbation theory are expected to work well, while the colour-octet contributions are of the same order of magnitude as the CS ones, however, in general make the agreement between theory and experiment better.