HAL : in2p3-00763082, version 1
 arXiv : 1212.1637
 First Measurement of the Neutral Current Excitation of the Delta Resonance on a Proton Target
 G0 Collaboration(s)
 (2012)
 The parity-violating asymmetry arising from inelastic electron-nucleon scattering at backward angle (~95 degrees) near the Delta(1232) resonance has been measured using a hydrogen target. From this asymmetry, we extracted the axial transition form factor G^A_{N\Delta}, a function of the axial Adler form factors C^A_i. Though G^A_{N\Delta} has been previously studied using charged current reactions, this is the first measurement of the weak neutral current excitation of the Delta using a proton target. For Q^2 = 0.34 (GeV/c)^2 and W = 1.18 GeV, the asymmetry was measured to be -33.4 \pm (5.3)_{stat} \pm (5.1)_{sys} ppm. The value of G^A_{N\Delta} determined from the hydrogen asymmetry was -0.05 \pm (0.35)_{stat} \pm (0.34)_{sys} \pm (0.06)_{theory}. These findings agree within errors with theoretical predictions for both the total asymmetry and the form factor. In addition to the hydrogen measurement, the asymmetry was measured at the same kinematics using a deuterium target. The asymmetry for deuterium was determined to be -43.6 \pm (14.6)_{stat} \pm (6.2)_{sys} ppm.
 Thème(s) : Physique/Physique Nucléaire Expérimentale
 Lien vers le texte intégral : http://fr.arXiv.org/abs/1212.1637
 in2p3-00763082, version 1 http://hal.in2p3.fr/in2p3-00763082 oai:hal.in2p3.fr:in2p3-00763082 Contributeur : Emmanuelle Vernay <> Soumis le : Lundi 10 Décembre 2012, 10:15:44 Dernière modification le : Lundi 10 Décembre 2012, 11:41:12