Measurement of the π0 differential cross-section with CLAS and outlook into 12 GeV Hall C

Abstract

Abstract. Photoproduction of the π 0 meson was studied using the CLAS detector at Thomas Jefferson National Accelerator Facility using tagged incident beam energies spanning the range E γ = 1.1 GeV -5.45 GeV. The measurement is performed on a liquid hydrogen target in the reaction γp → pe + e − (γ). The final state of the reaction is the sum of two subprocesses for π 0 decay, the Dalitz decay mode of π 0 → e + e − γ and conversion mode where one photon from π 0 → γγ decay is converted into a e + e − pair. This specific final state reaction avoided limitations caused by single prompt track triggering and allowed a kinematic range extension to the world data on π 0 photoproduction to a domain never systematically measured before. We report the measurement of the π 0 differential cross-sections dσ dΩ and dσ dt. The angular distributions agree well with the SAID parametrization for incident beam energies below 3 GeV, while an interpretation of the data for incident beam energies greater than 3 GeV is currently being developed. Included in the report will be a discussion of the future wide angle, exclusive photoproduction of π 0 experiment that will be performed in Hall C.