Measurement of inelastic J/psi and psi ' photoproduction at HERA

The reaction γ p → J/ψ p has been studied in ep interactions using the ZEUS detector at HERA. The cross section for elastic J/ψ photoproduction has been measured as a function of the photon-proton centre of mass energy W in the range 40 < W < 140 GeV at a median photon virtuality Q2 of...

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Xehetasun bibliografikoak
Egile Nagusiak: Abramowicz, H, Abt, I, Adamczyk, L, Adamus, M, Aggarwal, R, Antonelli, S, Antonioli, P, Antonov, A, Arneodo, M, Arslan, O, Aushev, V, Aushev, Y, Bachynska, O, Bamberger, A, Barakbaev, A, Barbagli, G, Bari, G, Barreiro, F, Bartosik, N, Bartsch, D, Basile, M, Behnke, O, Behr, J, Behrens, U, Bellagamba, L
Formatua: Journal article
Hizkuntza:English
Argitaratua: 2013
Deskribapena
Gaia:The reaction γ p → J/ψ p has been studied in ep interactions using the ZEUS detector at HERA. The cross section for elastic J/ψ photoproduction has been measured as a function of the photon-proton centre of mass energy W in the range 40 < W < 140 GeV at a median photon virtuality Q2 of 5 × 10-5 GeV2. The photoproduction cross section, σγp→J/ψp, is observed to rise steeply with W. A fit to the data presented in this paper to determine the parameter δ in the form σγp→J/ψp α Wδ yields the value δ = 0.92±0.14±0.10. The differential cross section dσ/d|t| is presented over the range |t| < 1.0 GeV2 where t is the square of the four-momentum exchanged at the proton vertex. dσ/d|t| falls exponentially with a slope parameter of 4.6 ± 0.4-0.6+0.4 GeV-2. The measured decay angular distributions are consistent with s-channel helicity conservation. © Springer-Verlag 1997.