Measurement of inelastic production in deep inelastic scattering at HERA

doi:10.1140/epjc/s2005-02346-2

EPJ

Measurement of inelastic $J/\psi$ production in deep inelastic scattering at HERA

The ZEUS Collaboration

Abstract

The inelastic production of $J/\psi$ mesons in ep collisions has been studied with the ZEUS detector at HERA using an integrated luminosity of $109{ \text{pb}^{-1}}$ . The $J/\psi$ mesons were identified using the decay channel $J/\psi\to\mu^{ + }\mu^{-}$ . The measurements were performed in the kinematic range $2 < Q^2 < 80 {\rm GeV}^2$ , $50 < W < 250 \text{GeV}$ , 0.2 < z < 0.9 and $-1.6 < Y_{\text{lab}} < 1.3$ , where Q ² is the virtuality of the exchanged photon, W is the photon-proton centre-of-mass energy, z is the fraction of the photon energy carried by the $J/\psi$ meson in the proton rest frame and $Y_{\text{lab}}$ is the rapidity of the $J/\psi$ in the laboratory frame. The measured cross sections are compared to theoretical predictions within the non-relativistic QCD framework including colour-singlet and colour-octet contributions, as well as to predictions based on the k _T-factorisation approach. Calculations of the colour-singlet process generally agree with the data, whereas inclusion of colour-octet terms spoils this agreement.

12 Internat. Congress of the Balkan Physical Union
July 8-12, 2025
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EPJ

Measurement of inelastic production in deep inelastic scattering at HERA

Conference announcements

Measurement of inelastic $J/\psi$ production in deep inelastic scattering at HERA