Measurement of Exclusive π0 Electroproduction Structure Functions and their Relationship to Transverse Generalized Parton Distributions

I. Bedlinshy; Angela Biselli

doi:10.1103/PhysRevLett.109.112001

Measurement of Exclusive π0 Electroproduction Structure Functions and their Relationship to Transverse Generalized Parton Distributions

I. Bedlinshy, Angela Biselli

Fairfield University

Research output: Contribution to journal › Article › peer-review

Abstract

<p> 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 ϕx1, 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.</p>

Original language	American English
Journal	Physical Review Letters
Volume	109
DOIs	https://doi.org/10.1103/PhysRevLett.109.112001
State	Published - Jan 1 2012

Disciplines

Physical Sciences and Mathematics
Physics

Access to Document

10.1103/PhysRevLett.109.112001License: CC BY

Measurement of Exclusive 0 Electroproduction Structure FunctionsFinal published version, 372 KBLicense: CC BY

Cite this

@article{e003451363084b989faf91c1276808a0,

title = "Measurement of Exclusive π0 Electroproduction Structure Functions and their Relationship to Transverse Generalized Parton Distributions",

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, xB, t, and \ϕx1, 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+\ϵ\σL, \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+\ϵ\σL 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.",

author = "I. Bedlinshy and Angela Biselli",

year = "2012",

month = jan,

day = "1",

doi = "10.1103/PhysRevLett.109.112001",

language = "American English",

volume = "109",

journal = "Physical Review Letters",

}

TY - JOUR

T1 - Measurement of Exclusive π0 Electroproduction Structure Functions and their Relationship to Transverse Generalized Parton Distributions

AU - Bedlinshy, I.

AU - Biselli, Angela

PY - 2012/1/1

Y1 - 2012/1/1

N2 - 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 ϕx1, 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.

AB - 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 ϕx1, 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.

UR - https://digitalcommons.fairfield.edu/physics-facultypubs/33

U2 - 10.1103/PhysRevLett.109.112001

DO - 10.1103/PhysRevLett.109.112001

M3 - Article

VL - 109

JO - Physical Review Letters

JF - Physical Review Letters

ER -

Measurement of Exclusive π0 Electroproduction Structure Functions and their Relationship to Transverse Generalized Parton Distributions

Abstract

Disciplines

Access to Document

Other files and links

Cite this