First measurement of target and double spin asymmetries for e?p??ep?0 in the nucleon resonance region above the ?(1232)

El Fassi, L.; Hafidi, K; Ball J.P.; Collins P.; Dugger, M.; Pasyuk, E.; Ritchie B.G.; Goetz, J. T.; Price, J. W.; Bellis M.; Bradford, R.; Dickson, R; Feuerbach, R; Krahn, Z; Kuhn J.; et. al.

Abstract

The exclusive channel p?(e?,e'p)?0 was studied in the first and second nucleon resonance regions in the Q2 range from 0.187 to 0.770 GeV2 at Jefferson Lab using the CEBAF Large Acceptance Spectrometer. Longitudinal target and beam-target asymmetries were extracted over a large range of center-of-mass angles of the ?0 and compared to the unitary isobar model MAID, the dynamic model by Sato and Lee, and the dynamic model DMT. A strong sensitivity to individual models was observed, in particular for the target asymmetry and in the higher invariant mass region. This data set, once included in the global fits of the above models, is expected to place strong constraints on the electrocoupling amplitudes A1/2 and S1/2 for the Roper resonance N(1400)P11 and the N(1535)S11 and N(1520)D13 states. © 2008 The American Physical Society.

Más información

Título de la Revista: Physical Review C - Nuclear Physics
Volumen: 78
Número: 4
Editorial: APS
Fecha de publicación: 2008
URL: http://www.scopus.com/inward/record.url?eid=2-s2.0-55049083732&partnerID=q2rCbXpz