Photo-production of psi(2S) mesons at HERA

Journal article

Quasi-elastic (z > 0.95) photo-production of ψ(2S) mesons has been observed at HERA for photon-proton centre-of-mass energies in the range 40 to 160 GeV. The ψ(2S) mesons were identified through their decays to ℓ+ℓ- and to J/ψπ+π-, where the J/ψ subsequently decays to ℓ+ℓ-, the lepton ℓ being either a muon or an electron. The cross-section for quasi-elastic photoproduction was measured to be (18.0 ± 2.8(stat) ± 3.0(syst)) nb at a photon-proton centre-of-mass energy of 80 GeV. The ratio of the ψ(2S) to J/ψ quasi-elastic cross-sections is (0.150 ± 0.027(stat) + 0.022(syst)). © 1998 Elsevier Science B.V.

Authors: Adloff, C; Aid, S; Anderson, M; Andreev, V; Andrieu, B

• Publication status: Published
• Journal: Physics Letters B
• Volume: 421
• Issue: 1-4
• Pages: 385-394
• Publication date: 1998-03-05
• DOI: 10.1016/S0370-2693(97)01529-3
• ISSN: 0370-2693
• Language: English