Resonances Using the CLAS Detector*

We present the study of the reaction γ p →K⁺ Λ^* using the photoproduction data from the CLAS-g12 experiment performed in Hall B of Jefferson Laboratory. Much is known about the photoproduction of the hyperon resonances Λ(1405)1/2^- and Λ(1520)3/2^-, but little is known about photoproduction to the higher-mass resonances Λ(1670)1/2^- and Λ(1690)3/2^-. In the quark model, the Λ(1405) and Λ(1520) resonances are assigned to the SU(3) singlet, where the Λ(1670) and Λ(1690) are assigned to the octet. The decay of Λ^* resonances, Λ(1520), Λ(1670), and Λ(1690), into two exclusive channels, Σ⁺π^- and Σ^-π⁺, is studied from the detected K⁺, π⁺, π^- particles. The Λ(1520) differential cross sections are in good agreement with the previous CLAS measurements and are extended to higher photon energies. Newly added are the differential cross sections as a function of invariant 4-momentum transfer t, which is the natural variable to use for a theoretical model based on a Regge-exchange reaction mechanism. No new N^* resonances decaying into the K⁺ Λ(1520) final state are found. The cross-sections for the higher mass resonances, Λ(1670) and Λ(1690), are studied for the first time using photoproduction.