Document Type


Publication Date




Publication Title

Physical Review Letters






112001 (6 pages)


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, xB , t , and ϕπ , in the Q2 range from 1.0 to 4.6  GeV2 , −t up to 2  GeV2 , and xB from 0.1 to 0.58. Structure functions σT+ϵσL , σTT , and σLT were extracted as functions of t for each of 17 combinations of Q2 and xB . 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.


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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


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