O(αs2)QCD corrections to the electroproduction of hadrons with high transverse momentum

Abstract

We compute the order α 2 s corrections to the one particle inclusive electroproduction cross section of hadrons with non vanishing transverse momentum. We perform the full calculation analytically, and obtain the expression of the factorized (finite) cross section at this order. We compare our results with H1 data on forward production of π 0 , and discuss the phenomenological implications of the rather large higher order contributions obtained in that case. Specifically, we analyze the cross section sensitivity to the factorization and renormalization scales, and to the input fragmentation functions, over the kinematical region covered by data. We conclude that the data is well described by the O(α 2 s ) predictions within the theoretical uncertainties and without the inclusion of any physics content beyond the DGLAP approach.

Global analysis of fragmentation functions for protons and charged hadrons

“…Specifically, we have demonstrated that the pQCD framework based on factorized cross sections can consistently account for a large variety of processes with hadrons in the final-state with remarkable precision, producing at the same time accurate and universal sets of fragmentation functions. The availability of these crucial non-perturbative inputs now opens a wide range of possibilities for detailed studies of the nu- cleon structure at NLO accuracy through single-inclusive hadroproduction processes, encompassing the study of the spin and flavor structure with polarized SIDIS measurements [26], in proton-proton collisions [27], and in photoproduction [28], the modification of parton densities by nuclear effects [29], or studies of high p T electroproduction processes [30].…”

Next-to-leading order transverse momentum-weighted Sivers asymmetry in semi-inclusive deep inelastic scattering: The role of the three-gluon correlator

“…In the following (and throughout the paper) we will only consider the so-called metric contribution [44][45][46][47], i.e. we contract w µν with −g µν and write w = [−g µν w µν ] below.…”

Resummation for polarized semi-inclusive deep-inelastic scattering at small transverse momentum

“…They are expected to be adequate (at least qualitatively) for achieving a good theoretical description at large transverse momentum, q T ∼ Q. In the unpolarized case, the complete next-to-leading (NLO) (O(α 2 s )) corrections to the q T -distribution have been calculated [11,12,13] which will lead to an improvement of the theoretical calculation at large q T . 1 At low transverse momentum, q T ≪ Q, fixed-order calculations are bound to fail.…”