The production of φ mesons in the reaction e+p → e+φp (φ → K+K-) at a median Q2 of 10-4 GeV2 has been studied with the ZEUS detector at HERA. The differential φ photoproduction cross section dσ/dt has an exponential shape and has been determined in the kinematic range 0.1 < |t| < 0.5 GeV2 and 60 < W < 80 GeV. An integrated cross section of σγp→φp = 0.96 ± 0.19+0.21-.18 μb has been obtained by extrapolating to t = 0. When compared to lower energy data, the results show a weak energy dependence of both σγp→φp and the slope of the t distribution. The φ decay angular distributions are consistent with s-channel helicity conservation. From lower energies to HERA energies, the features of φ photoproduction are compatible with those of a soft diffractive process.
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Derrick, M.; Krakauer, D.; Magill, S.; Mikunas, D.; Musgrave, B.; Okrasinski, J. R.; Repond, J.; Stanek, R.; Talaga, R. L.; Zhang, H.; Mattingly, Margarita C. K.; Bari, G.; Basile, M.; Bellagamba, L.; Boscherini, D.; Bruni, A.; Bruni, G.; Bruni, R.; Cara Romeo, G.; Castellini, G.; Cifarelli, L.; Cindolo, F.; Contin, A.; Corradi, M.; Gialas, I.; Giusti, P.; Iacobucci, G.; Laurenti, G.; Levi, G.; Margotti, A.; and Massam, T., "Measurement of Elastic Φ Photoproduction at HERA" (1996). Faculty Publications. 2668.
Accepted version retrieved July 19, 2021 from https://arxiv.org/pdf/hep-ex/9601009.pdf