Measurement of Exclusive πº Electroproduction Structure Functions and their Relationship to Transverse Generalized Parton Distributions

Authors

CLAS Collaboration
K. P. Adhikari, Old Dominion University
M. J. Amaryan, Old Dominion UniversityFollow
R. P. Bennett, Old Dominion University
S. Koirala, Old Dominion University
S. E. Kuhn, Old Dominion UniversityFollow
M. Mayer, Old Dominion University
L. B. Weinstein, Old Dominion UniversityFollow
I. Bedlinsky
V. Kubarovsky

Document Type

Article

Publication Date

2012

DOI

10.1103/PhysRevLett.109.112001

Publication Title

Physical Review Letters

Volume

109

Issue

11

Pages

112001 (6 pages)

Abstract

Exclusive π⁰ electroproduction at a beam energy of 5.75 GeV has been measured with the Jefferson Lab CLAS spectrometer. Differential cross sections were measured at more than 1800 kinematic values in Q², x_B , t , and ϕπ , in the Q² range from 1.0 to 4.6  GeV² , −t up to 2  GeV² , and x_B from 0.1 to 0.58. Structure functions σ_T+ϵσ_L , σ_TT , and σ_LT were extracted as functions of t for each of 17 combinations of Q² and x_B . The data were compared directly with two handbag-based calculations including both longitudinal and transversity generalized parton distributions (GPDs). Inclusion of only longitudinal GPDs very strongly underestimates σT+ϵσL and fails to account for σTT and σLT , while inclusion of transversity GPDs brings the calculations into substantially better agreement with the data. There is very strong sensitivity to the relative contributions of nucleon helicity-flip and helicity nonflip processes. The results confirm that exclusive π⁰ electroproduction offers direct experimental access to the transversity GPDs.

Comments

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© 2012 American Physical Society

Original Publication Citation

Collaboration, C., Bedlinskiy, I., Kubarovsky, V., Niccolai, S., Stoler, P., Adhikari, K. P., . . . Zonta, I. (2012). Measurement of exclusive πº electroproduction structure functions and their relationship to transverse generalized parton distributions. Physical Review Letters, 109(11), 112001. doi:10.1103/PhysRevLett.109.112001

ORCID

0000-0003-2243-6836 (Kuhn)

Repository Citation

CLAS Collaboration; Adhikari, K. P.; Amaryan, M. J.; Bennett, R. P.; Koirala, S.; Kuhn, S. E.; Mayer, M.; Weinstein, L. B.; Bedlinsky, I.; and Kubarovsky, V., "Measurement of Exclusive πº Electroproduction Structure Functions and their Relationship to Transverse Generalized Parton Distributions" (2012). Physics Faculty Publications. 366.
https://digitalcommons.odu.edu/physics_fac_pubs/366