Measurement of the cross-section ratio σψ(2S)/σJ/ψ(1S) in deep inelastic exclusive ep scattering at HERA

Journal article

The exclusive deep inelastic electroproduction of ψ(2S) and J/ψ(1S) at an ep centre-of-mass energy of 317 GeV has been studied with the ZEUS detector at HERA in the kinematic range 2 < Q2 < 80 GeV2, 30 <W< 210 GeV and |t| < 1 GeV2, where Q2 is the photon virtuality, W is the photon–proton centre-of-mass energy and t is the squared four-momentum transfer at the proton vertex. The data for 2 < Q2 < 5 GeV2 were taken in the HERA I running period and correspond to an integrated luminosity of 114 pb−1. The data for 5 < Q2 < 80 GeV2 are from both HERA I and HERA II periods and correspond to an integrated luminosity of 468 pb−1. The decay modes analysed were μ+μ− and J/ψ(1S)π+π− for the ψ(2S) and μ+μ− for the J/ψ(1S). The cross-section ratio σψ(2S)/σJ/ψ(1S) has been measured as a function of Q2, W and t. The results are compared to predictions of QCD-inspired models of exclusive vector-meson production.

Authors: Abramowicz, H; Abt, I; Adamczyk, L; Adamus, M; Antonelli, S

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Elsevier
• Journal: Nuclear Physics B
• Publication date: 2016-08-01
• Acceptance date: 2016-06-07
• DOI: 10.1016/j.nuclphysb.2016.06.010
• ISSN: 0550-3213
• Keywords: Journal Article