The exclusive electroproduction process (e) over right arrowp -> e(')n pi(+) was measured in the range of the photon virtuality Q(2)=1.7-4.5 GeV(2), and the invariant mass range for the n pi(+) system of W=1.15-1.7 GeV using the CEBAF Large Acceptance Spectrometer. For the first time, these kinematics are probed in exclusive pi(+) production from protons with nearly full coverage in the azimuthal and polar angles of the n pi(+) center-of-mass system. The n pi(+) channel has particular sensitivity to the isospin 1/2 excited nucleon states, and together with the p pi(0) final state will serve to determine the transition form factors of a large number of resonances. The largest discrepancy between these results and present modes was seen in the sigma(')(LT) structure function. In this experiment, 31,295 cross section and 4,184 asymmetry data points were measured. Because of the large volume of data, only a reduced set of structure functions and Legendre polynomial moments can be presented that are obtained in model-independent fits to the differential cross sections.

Cross sections and beam asymmetries for vec(e) p ---> en pi+ in the nucleon resonance region for 1.7

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

Abstract

The exclusive electroproduction process (e) over right arrowp -> e(')n pi(+) was measured in the range of the photon virtuality Q(2)=1.7-4.5 GeV(2), and the invariant mass range for the n pi(+) system of W=1.15-1.7 GeV using the CEBAF Large Acceptance Spectrometer. For the first time, these kinematics are probed in exclusive pi(+) production from protons with nearly full coverage in the azimuthal and polar angles of the n pi(+) center-of-mass system. The n pi(+) channel has particular sensitivity to the isospin 1/2 excited nucleon states, and together with the p pi(0) final state will serve to determine the transition form factors of a large number of resonances. The largest discrepancy between these results and present modes was seen in the sigma(')(LT) structure function. In this experiment, 31,295 cross section and 4,184 asymmetry data points were measured. Because of the large volume of data, only a reduced set of structure functions and Legendre polynomial moments can be presented that are obtained in model-independent fits to the differential cross sections.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11567/226361
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