$\gamma p \rightarrow K^{+}\Lambda$ Differential Cross Section and Recoil Polarization Measurements from the CLAS \textit{g11a} Dataset

We present measurements of $\gamma p \rightarrow K^{+}\Lambda$ differential cross section and $\Lambda$ recoil polarization from the CLAS \textit{g11a} dataset. The measurements cover the center-of-mass energy range from 1.62~GeV to 2.84~GeV and a wide range of center-of-mass angles ($-0.90\leq\cos\theta_{CM}^{K}\leq0.90$). We have analyzed this reaction via both the $K^{+}p\pi^{-}$ and $K^{+}p$ (missing $\pi^{-}$) final-state topologies independently and found the results to be in excellent agreement. Previous $\gamma p \rightarrow K^{+}\Lambda$ differential cross section results from the CLAS (Bradford, \textit{et al.} 2005) and SAPHIR (Glander, \textit{et al.}, 2004) Collaborations show discrepancies in magnitude at most energies and a discrepancy in scale and shape at ${\sqrt{s}\approx 1.9~\textrm{GeV}}$. These discrepancies have been problematic for interpretations of $K^{+}\Lambda$ photoproduction mechanisms. These new \textit{g11a} differential cross section results show excellent agreement with the previous CLAS result. The recoil polarization results show agreement with previous data from the CLAS, SAPHIR, and GRAAL experiments, and are a $\approx 500$~MeV extension of the observed energy range.