Inelastic production of J/psi mesons in photoproduction and deep inelastic scattering at HERA

Abstract

Inelastic photo-and electroproduction of J/ψ mesons is studied in ep scattering at HERA. The data were recorded with the H1 detector in the period from 2004 to 2007. Single and double differential cross sections are determined and helicity distributions of the J/ψ mesons are analysed. The results are compared to theoretical predictions in the colour singlet model and in the framework of non-relativistic QCD. Calculations in the colour singlet model using a k T factorisation ansatz describe the data well, while colour singlet model calculations to next-to-leading order in collinear factorisation underestimate the data.

Heavy flavours in DIS and hadron colliders: WG summary

“…At HERA inelastic J/ψ photoproduction cross sections and polarisation are measured [14,15] and compared to the calculations of Colour-Singlet (CS) and Colour-Octet (CO) models in Non-Relativistic QCD (NRQCD), and in the framework of k T -factorisation in Fig. 1.…”