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Title: Target and double spin asymmetries of deeply virtual π 0 production with a longitudinally polarized proton target and CLAS

The target and double spin asymmetries of the exclusive pseudoscalar channel $$\vec e\vec p\to ep\pi^0$$ were measured for the first time in the deep-inelastic regime using a longitudinally polarized 5.9 GeV electron beam and a longitudinally polarized proton target at Jefferson Lab with the CEBAF Large Acceptance Spectrometer (CLAS). The data were collected over a large kinematic phase space and divided into 110 four-dimensional bins of $Q^2$, $$x_B$$, $-t$ and $$\phi$$. Large values of asymmetry moments clearly indicate a substantial contribution to the polarized structure functions from transverse virtual photon amplitudes. The interpretation of experimental data in terms of generalized parton distributions (GPDs) provides the first insight on the chiral-odd GPDs $$\tilde{H}_T$$ and $$E_T$$, and complement previous measurements of unpolarized structure functions sensitive to the GPDs $$H_T$$ and $$\bar E_T$$. Finally, these data provide necessary constraints for chiral-odd GPD parametrizations and will strongly influence existing theoretical handbag models.
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Publication Date:
Report Number(s):
JLAB-PHY-17-2440; DOE/OR/23177-4111; arXiv:1511.03338
Journal ID: ISSN 0370-2693; PII: S037026931730134X; TRN: US1700695
Grant/Contract Number:
AC05-06OR23177; SC0016583
Type:
Published Article
Journal Name:
Physics Letters. Section B
Additional Journal Information:
Journal Volume: 768; Journal Issue: C; Journal ID: ISSN 0370-2693
Publisher:
Elsevier
Research Org:
Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); George Washington Univ., Washington, DC (United States)
Sponsoring Org:
USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; nucleon structure; CLAS collaboration; deeply virtual meson production; chiral-odd generalized parton distributions; longitudinally polarized target; inclusive reaction
OSTI Identifier:
1344582
Alternate Identifier(s):
OSTI ID: 1351109; OSTI ID: 1439852