ϕ photoproduction on the proton at Eγ=1.5–2.9GeV

Differential cross sections at $t=t_{\text{min}}$ and decay asymmetries for the $\gamma p\rightarrow\phi p$ reaction have been measured using linearly polarized photons in the range 1.5 to 2.9 GeV. These cross sections were used to determine the Pomeronstrength factor. The cross sections and decay asymmetries are consistently described by the $t$-channel Pomeronand pseudoscalarexchange model in the $E_{\gamma}$ region above 2.37 GeV. In the lower energy region, an excess over the model prediction is observed in the energy dependence of the differential cross sections at $t=t_{\text{min}}$. This observation suggests that additional processes or interference effects between Pomeronexchange and other processes appear near the threshold region.