Résumé du preprint Irfu-09-13

Irfu-09-13
A measurement of the differential cross section for the reaction gamma n -> pi- p from deuterium.
W. Chen et al (J.M. Laget, M. Garçon, F.X. Girod, F. Sabatié)
We report a measurement of the differential cross section for the process from the CLAS detector at Jefferson Lab in Hall B for photon energies between 1.0 and 3.5 GeV and pion center-of-mass (c.m.) angles (theta_cm) between 50° and 115°. We confirm a previous indication of a broad enhancement around a c.m. energy of 2.2 GeV at theta_cm = 90° in the scaled differential cross section, s7 dsigma/dt. Our data show the angular dependence of this enhancement as the scaling region is approached in the kinematic region from 70° to 105°.