A study of kaon(+) lambda photoproduction in the CLAS g11a dataset: Differential cross section, recoil polarization, and a partial-wave analysis

We present measurements of gammap → K+Λ differential cross section and Λ recoil polarization from the CLAS g11a dataset. The measurements cover the center-of-mass energy range from 1.62 GeV to 2.84 GeV, expanding the observed range of this reaction by roughly 300 MeV. We have analyzed this reaction via both the K+ppi - and K+p(pi -) final state topologies independently and found excellent agreement. The precision of these g11a measurements improves characterization of this reaction and displays very good agreement with previous CLAS measurements.;A preliminary partial-wave analysis has also been performed using binned chi 2 fits to g11a differential cross section and recoil polarization results as well as previous CLAS g1c beam-recoil polarization results. A model of non-resonant photoproduction has been assembled based upon the t-channel K+, K*(892), and K1(1270) exchange diagrams. We have found evidence of contributions of the four-star S 11(1650), P13(1720), and F 15(1680) states to this reaction near threshold. In the s range 1.8 GeV to 2.0 GeV, the data show evidence of the presence of multiple 32 + states and a single 1/2- state at s ≈ 1.92 GeV.