gp g K+L Cross section measurement -0.55 < qK+ < -0.45 Example Cross section for cos(qK+) = -0.5 Black = our data Red = SAPHIR data (2004) Blue = JLab data (2006) T C Jude, The University of Edinburgh, Strangeness Photoproduction A2 Analysis meeting, Mainz, September 2008

Adopt JLab convention: ~ 0.6 Target pressure ~ 70.548 kgm-3 Corresponds to 4.2179E(28) protons m-3 Target length = 0.048 m Target density per unit area, r = 2.0246E(27) protons m-2 So W = 0.1 Adopt JLab convention: T C Jude, The University of Edinburgh, Strangeness Photoproduction A2 Analysis meeting, Mainz, September 2008

= T C Jude, The University of Edinburgh, Strangeness Photoproduction A2 Analysis meeting, Mainz, September 2008

= = 5 million simulated events: gp g K+ L K+ Out K+ In T C Jude, The University of Edinburgh, Strangeness Photoproduction A2 Analysis meeting, Mainz, September 2008

T C Jude, The University of Edinburgh, Strangeness Photoproduction A2 Analysis meeting, Mainz, September 2008

Total energy deposited in the Crystal Ball: Large energy sum on the trigger: (July 07 data) Reduced data? Simulation Expt K+ detection (simulation) 330 MeV energy sum in CB 100 MeV energy sum in CB Cut imposed on data for efficiency measurements q (lab frame) [deg] T C Jude, The University of Edinburgh, Strangeness Photoproduction A2 Analysis meeting, Mainz, September 2008