Bottom quark production cross section at fixed-target $pp$ experiments

TL;DR

The paper addresses bottom quark production in fixed-target pp collisions, focusing on the importance of threshold soft-gluon resummation. It develops a comprehensive framework combining LO, NLO, and all-order resummation (including Coulomb and π^2 corrections) for qq̄ and gg partonic channels, with careful attention to scheme differences (MS̄ vs DIS). Applying this to HERA-B kinematics, the gg channel dominates and resummation substantially increases cross sections and stabilizes predictions, yielding improved total cross sections and differential distributions. The work underscores the significance of threshold effects in fixed-target heavy-quark production and highlights areas for further refinement of subleading terms.

Abstract

The cross section for bottom quark production at fixed-target energies is calculated for a wide range of beam momenta. A detailed analysis is given for the HERA-B experiment. We consider both the order $α_s^3$ cross section and the resummation of soft gluon corrections in all orders of QCD perturbation theory. The inclusive transverse momentum and rapidity distributions, including resummation, for bottom quark production at HERA-B are also presented.