CLAS Physics Database

g1c

Spokesperson
Michael Dugger
Year
2009
Abstract
Differential cross sections for the reaction γ p -> n π+ have been measured with the CEBAF Large Acceptance Spectrometer (CLAS) and a tagged photon beam with energies from 0.725 to 2.875 GeV. Where available, the results obtained here compare well with previously published results for the reaction. Agreement with the SAID and MAID analyses is found below 1 GeV. The present set of cross sections has been incorporated into the SAID database, and exploratory fits have been made up to 2.7 GeV. Resonance couplings have been extracted and compared to previous determinations. With the addition of these cross sections to the world data set, significant changes have occurred in the high-energy behavior of the SAID cross-section predictions and amplitudes.
Publication
  1. The CLAS Collaboration: M. Dugger, B.G. Ritchie, J.P. Ball, P. Collins, E. Pasyuk, R.A. Arndt, W.J. Briscoe, I.I. Strakovsky, R.L. Workman, et al π+ photoproduction on the proton for photon energies from 0.725 to 2.875 GeV // PRC 79, 065206 (2009)
Quantities
dσ/dΩ

Measurements

ID Quantity Beam Target Final state Q2min,
GeV2
Q2max,
GeV2
Wmin,
GeV
Wmax,
GeV
E131M1 dσ/dΩ γ p π+n 0.0 0.0 2.11 2.5