836 articles – 5645 Notices  [english version]
 HAL : in2p3-00762236, version 1
 arXiv : 1211.6460
 Physical Review C 87 (2013) 045205
 Near Threshold Neutral Pion Electroproduction at High Momentum Transfers and Generalized Form Factors
 CLAS Collaboration(s)
 (2013)
 We report the measurement of near threshold neutral pion electroproduction cross sections and the extraction of the associated structure functions on the proton in the kinematic range $Q^2$ from 2 to 4.5 GeV$^2$ and $W$ from 1.08 to 1.16 GeV. These measurements allow us to access the dominant pion-nucleon s-wave multipoles $E_{0+}$ and $S_{0+}$ in the near-threshold region. In the light-cone sum-rule framework (LCSR), these multipoles are related to the generalized form factors $G_1^{\pi^0 p}(Q^2)$ and $G_2^{\pi^0 p}(Q^2)$. The data are compared to these generalized form factors and the results for $G_1^{\pi^0 p}(Q^2)$ are found to be in good agreement with the LCSR predictions, but the level of agreement with $G_2^{\pi^0 p}(Q^2)$ is poor.
 Thème(s) : Physique/Physique Nucléaire Expérimentale
 Lien vers le texte intégral : http://fr.arXiv.org/abs/1211.6460
 in2p3-00762236, version 1 http://hal.in2p3.fr/in2p3-00762236 oai:hal.in2p3.fr:in2p3-00762236 Contributeur : Emmanuelle Vernay <> Soumis le : Jeudi 6 Décembre 2012, 16:41:30 Dernière modification le : Mardi 16 Avril 2013, 08:23:05