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.
Publication Source (Journal or Book title)
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Derrick, M., Krakauer, D., Magill, S., Mikunas, D., Musgrave, B., Okrasinski, J., Repond, J., Stanek, R., Talaga, R., Zhang, H., Mattingly, M., 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., Massam, T., Nania, R., & Palmonari, F. (1996). Measurement of elastic φ photoproduction at HERA. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 377 (4), 259-272. https://doi.org/10.1016/0370-2693(96)00172-4