| Popis: |
Differential cross sections in the forward direction for π + , π o and K + photoproduction are evaluated with Regge trajectories exchange in the t -channel. Kinematical singularities, constraints among helicity amplitudes, conspiracy and evasion, have been studied very carefully. A very good fit is obtained for γ p → π o p. assuming ω and B exchange and with only three parameters, for 2 ⩽ Eγ ⩽ 5 GeV and transfer momentum t up to −3 (GeV/ c ) 2 . Good agreement is also observed for γ p → π + n with π and B exchange, and for γ p → Λ o K + and γ p → Σ o K + with K and K ∗ exchange. Present experimental data seem to exhibit violations of the SU 3 symmetry. |
