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

CLAS Collaboration; I. Bedlinskiy; V. Kubarovsky; S. Niccolai; P. Stoler; K. P. Adhikari; M. Aghasyan; M. J. Amaryan; M. Anghinolfi; H. Avakian; H. Baghdasaryan; J. Ball; N. A. Baltzell; M. Battaglieri; R. P. Bennett; A. S. Biselli; C. Bookwalter; S. Boiarinov; W. J. Briscoe; W. K. Brooks; V. D. Burkert; D. S. Carman; A. Celentano; S. Chandavar; G. Charles; M. Contalbrigo; V. Crede; A. D'Angelo; A. Daniel; N. Dashyan; R. De Vita; E. De Sanctis; A. Deur; C. Djalali; D. Doughty; R. Dupre; H. Egiyan; A. El Alaoui; L. El Fassi; L. Elouadrhiri; P. Eugenio; G. Fedotov; S. Fegan; J. A. Fleming; T. A. Forest; A. Fradi; M. Garcon; N. Gevorgyan; K. L. Giovanetti; D. P. Watts; J. Zhang

doi:10.1103/PhysRevLett.109.112001

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

CLAS Collaboration, I. Bedlinskiy^*, V. Kubarovsky, S. Niccolai, P. Stoler, K. P. Adhikari, M. Aghasyan, M. J. Amaryan, M. Anghinolfi, H. Avakian, H. Baghdasaryan, J. Ball, N. A. Baltzell, M. Battaglieri, R. P. Bennett, A. S. Biselli, C. Bookwalter, S. Boiarinov, W. J. Briscoe, W. K. BrooksV. D. Burkert, D. S. Carman, A. Celentano, S. Chandavar, G. Charles, M. Contalbrigo, V. Crede, A. D'Angelo, A. Daniel, N. Dashyan, R. De Vita, E. De Sanctis, A. Deur, C. Djalali, D. Doughty, R. Dupre, H. Egiyan, A. El Alaoui, L. El Fassi, L. Elouadrhiri, P. Eugenio, G. Fedotov, S. Fegan, J. A. Fleming, T. A. Forest, A. Fradi, M. Garcon, N. Gevorgyan, K. L. Giovanetti, D. P. Watts, J. Zhang

^*Corresponding author for this work

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

Abstract / Description of output

Exclusive pi(0) 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 Q(2), x(B), t, and phi(pi), in the Q(2) range from 1.0 to 4.6 GeV2, -t up to 2 GeV2, and x(B) from 0.1 to 0.58. Structure functions sigma(T) + epsilon sigma(L), sigma(TT), and sigma(LT) were extracted as functions of t for each of 17 combinations of Q(2) 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 sigma(T) + epsilon sigma(L) and fails to account for sigma(TT) and sigma(LT), 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 pi(0) electroproduction offers direct experimental access to the transversity GPDs.

Original language	English
Article number	112001
Number of pages	6
Journal	Physical Review Letters
Volume	109
Issue number	11
DOIs	https://doi.org/10.1103/PhysRevLett.109.112001
Publication status	Published - 10 Sept 2012

Keywords / Materials (for Non-textual outputs)

PION ELECTROPRODUCTION

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10.1103/PhysRevLett.109.112001

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CLAS Collaboration, Bedlinskiy, I., Kubarovsky, V., Niccolai, S., Stoler, P., Adhikari, K. P., Aghasyan, M., Amaryan, M. J., Anghinolfi, M., Avakian, H., Baghdasaryan, H., Ball, J., Baltzell, N. A., Battaglieri, M., Bennett, R. P., Biselli, A. S., Bookwalter, C., Boiarinov, S., Briscoe, W. J., ... Zhang, J. (2012). Measurement of Exclusive π0 Electroproduction Structure Functions and their Relationship to Transverse Generalized Parton Distributions. Physical Review Letters, 109(11), Article 112001. https://doi.org/10.1103/PhysRevLett.109.112001

@article{bf296b3a799a4bb99f2ee3bf0fa5f23e,

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

abstract = "Exclusive pi(0) 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 Q(2), x(B), t, and phi(pi), in the Q(2) range from 1.0 to 4.6 GeV2, -t up to 2 GeV2, and x(B) from 0.1 to 0.58. Structure functions sigma(T) + epsilon sigma(L), sigma(TT), and sigma(LT) were extracted as functions of t for each of 17 combinations of Q(2) 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 sigma(T) + epsilon sigma(L) and fails to account for sigma(TT) and sigma(LT), 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 pi(0) electroproduction offers direct experimental access to the transversity GPDs.",

keywords = "PION ELECTROPRODUCTION",

author = "{CLAS Collaboration} and I. Bedlinskiy and V. Kubarovsky and S. Niccolai and P. Stoler and Adhikari, {K. P.} and M. Aghasyan and Amaryan, {M. J.} and M. Anghinolfi and H. Avakian and H. Baghdasaryan and J. Ball and Baltzell, {N. A.} and M. Battaglieri and Bennett, {R. P.} and Biselli, {A. S.} and C. Bookwalter and S. Boiarinov and Briscoe, {W. J.} and Brooks, {W. K.} and Burkert, {V. D.} and Carman, {D. S.} and A. Celentano and S. Chandavar and G. Charles and M. Contalbrigo and V. Crede and A. D'Angelo and A. Daniel and N. Dashyan and {De Vita}, R. and {De Sanctis}, E. and A. Deur and C. Djalali and D. Doughty and R. Dupre and H. Egiyan and {El Alaoui}, A. and {El Fassi}, L. and L. Elouadrhiri and P. Eugenio and G. Fedotov and S. Fegan and Fleming, {J. A.} and Forest, {T. A.} and A. Fradi and M. Garcon and N. Gevorgyan and Giovanetti, {K. L.} and Watts, {D. P.} and J. Zhang",

year = "2012",

month = sep,

day = "10",

doi = "10.1103/PhysRevLett.109.112001",

language = "English",

volume = "109",

journal = "Physical Review Letters",

issn = "0031-9007",

publisher = "American Physical Society",

number = "11",

}

CLAS Collaboration, Bedlinskiy, I, Kubarovsky, V, Niccolai, S, Stoler, P, Adhikari, KP, Aghasyan, M, Amaryan, MJ, Anghinolfi, M, Avakian, H, Baghdasaryan, H, Ball, J, Baltzell, NA, Battaglieri, M, Bennett, RP, Biselli, AS, Bookwalter, C, Boiarinov, S, Briscoe, WJ, Brooks, WK, Burkert, VD, Carman, DS, Celentano, A, Chandavar, S, Charles, G, Contalbrigo, M, Crede, V, D'Angelo, A, Daniel, A, Dashyan, N, De Vita, R, De Sanctis, E, Deur, A, Djalali, C, Doughty, D, Dupre, R, Egiyan, H, El Alaoui, A, El Fassi, L, Elouadrhiri, L, Eugenio, P, Fedotov, G, Fegan, S, Fleming, JA, Forest, TA, Fradi, A, Garcon, M, Gevorgyan, N, Giovanetti, KL, Watts, DP & Zhang, J 2012, 'Measurement of Exclusive π0 Electroproduction Structure Functions and their Relationship to Transverse Generalized Parton Distributions', Physical Review Letters, vol. 109, no. 11, 112001. https://doi.org/10.1103/PhysRevLett.109.112001

TY - JOUR

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

AU - CLAS Collaboration

AU - Bedlinskiy, I.

AU - Kubarovsky, V.

AU - Niccolai, S.

AU - Stoler, P.

AU - Adhikari, K. P.

AU - Aghasyan, M.

AU - Amaryan, M. J.

AU - Anghinolfi, M.

AU - Avakian, H.

AU - Baghdasaryan, H.

AU - Ball, J.

AU - Baltzell, N. A.

AU - Battaglieri, M.

AU - Bennett, R. P.

AU - Biselli, A. S.

AU - Bookwalter, C.

AU - Boiarinov, S.

AU - Briscoe, W. J.

AU - Brooks, W. K.

AU - Burkert, V. D.

AU - Carman, D. S.

AU - Celentano, A.

AU - Chandavar, S.

AU - Charles, G.

AU - Contalbrigo, M.

AU - Crede, V.

AU - D'Angelo, A.

AU - Daniel, A.

AU - Dashyan, N.

AU - De Vita, R.

AU - De Sanctis, E.

AU - Deur, A.

AU - Djalali, C.

AU - Doughty, D.

AU - Dupre, R.

AU - Egiyan, H.

AU - El Alaoui, A.

AU - El Fassi, L.

AU - Elouadrhiri, L.

AU - Eugenio, P.

AU - Fedotov, G.

AU - Fegan, S.

AU - Fleming, J. A.

AU - Forest, T. A.

AU - Fradi, A.

AU - Garcon, M.

AU - Gevorgyan, N.

AU - Giovanetti, K. L.

AU - Watts, D. P.

AU - Zhang, J.

PY - 2012/9/10

Y1 - 2012/9/10

N2 - Exclusive pi(0) 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 Q(2), x(B), t, and phi(pi), in the Q(2) range from 1.0 to 4.6 GeV2, -t up to 2 GeV2, and x(B) from 0.1 to 0.58. Structure functions sigma(T) + epsilon sigma(L), sigma(TT), and sigma(LT) were extracted as functions of t for each of 17 combinations of Q(2) 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 sigma(T) + epsilon sigma(L) and fails to account for sigma(TT) and sigma(LT), 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 pi(0) electroproduction offers direct experimental access to the transversity GPDs.

AB - Exclusive pi(0) 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 Q(2), x(B), t, and phi(pi), in the Q(2) range from 1.0 to 4.6 GeV2, -t up to 2 GeV2, and x(B) from 0.1 to 0.58. Structure functions sigma(T) + epsilon sigma(L), sigma(TT), and sigma(LT) were extracted as functions of t for each of 17 combinations of Q(2) 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 sigma(T) + epsilon sigma(L) and fails to account for sigma(TT) and sigma(LT), 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 pi(0) electroproduction offers direct experimental access to the transversity GPDs.

KW - PION ELECTROPRODUCTION

U2 - 10.1103/PhysRevLett.109.112001

DO - 10.1103/PhysRevLett.109.112001

M3 - Article

SN - 0031-9007

VL - 109

JO - Physical Review Letters

JF - Physical Review Letters

IS - 11

M1 - 112001

ER -

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

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Keywords / Materials (for Non-textual outputs)

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