Study of the reactions γp → K + Σ ± π ∓ at photon energies up to 2.6 GeV

The reactions γ p → K + Σ ± π ∓ were studied with the SAPHIR detector using a tagged photon beam at the electron stretcher facility ELSA in Bonn. The decays Σ − → nπ − and Σ + → nπ + , pπ 0 were fully reconstructed. Reaction cross-sections were measured as a function of the photon energy from threshold up to 2.6 GeV with considerably improved statistics compared to a previous bubble chamber measurement. The cross-sections rise monotonically with increasing photon energy. The two-particle mass distributions of Σ ± π ∓ and K + π − show substantial production of resonant states.