The beam spin asymmetry (BSA) in the exclusive reaction ep -> ep pi(0) was measured with the CEBAF 5.77 GeV polarized electron beam and Large Acceptance Spectrometer (CLAS). The x(B),Q(2),t, and phi dependences of the pi(0) BSA are presented in the deep inelastic regime. The asymmetries are fitted with a sin phi function and their amplitudes are extracted. Overall, they are of the order of 0.04-0.11 and roughly independent of t. This is the signature of a nonzero longitudinal-transverse interference. The implications concerning the applicability of a formalism based on generalized parton distributions, as well as the extension of a Regge formalism at high photon virtualities, are discussed.

Measurement of ep --> eppi0 beam spin asymmetries above the resonance region

RICCO, GIOVANNI;TAIUTI, MAURO GINO;
2008-01-01

Abstract

The beam spin asymmetry (BSA) in the exclusive reaction ep -> ep pi(0) was measured with the CEBAF 5.77 GeV polarized electron beam and Large Acceptance Spectrometer (CLAS). The x(B),Q(2),t, and phi dependences of the pi(0) BSA are presented in the deep inelastic regime. The asymmetries are fitted with a sin phi function and their amplitudes are extracted. Overall, they are of the order of 0.04-0.11 and roughly independent of t. This is the signature of a nonzero longitudinal-transverse interference. The implications concerning the applicability of a formalism based on generalized parton distributions, as well as the extension of a Regge formalism at high photon virtualities, are discussed.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11567/226436
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