Measurement of the reaction $γp \rightarrow K^ + Σ^{\pm}π^{\mp}$ at photon energies up to 2.6 GeV

Abstract

The reactions $γp \rightarrow K^{+}Σ^{\pm}π^{\mp}$ were studied with the SAPHIR detector using a tagged photon beam at the electron stretcher facility ELSA in Bonn. The decays $Σ^{-} \rightarrow nπ^{-}$ and $Σ^{+} \rightarrow nπ^{+}, pπ^0$ 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 monotonously with increasing photon energy. The two-particle mass distributions of $Σ^{\pm}π^{\mp}$ and $K^+π^-$ show substantial production of resonant states.

6 pages, 12 figures, 4 tables