Target and beam-target spin asymmetries in exclusive pion electroproduction for Q(2) > 1 GeV2. II. ep -> e pi(0) p

CLAS Collaboration; P. E. Bosted; A. Kim; K. P. Adhikari; D. Adikaram; Z. Akbar; M. J. Amaryan; S. Anefalos Pereira; H. Avakian; R. A. Badui; J. Ball; I. Balossino; M. Battaglieri; I. Bedlinskiy; A. S. Biselli; S. Boiarinov; W. J. Briscoe; W. K. Brooks; S. Bultmann; V. D. Burkert; T. Cao; D. S. Carman; A. Celentano; S. Chandavar; G. Charles; T. Chetry; G. Ciullo; L. Clark; L. Colaneri; P. L. Cole; M. Contalbrigo; O. Cortes; V. Crede; A. D'Angelo; N. Dashyan; R. De Vita; E. De Sanctis; A. Deur; C. Djalali; R. Dupre; H. Egiyan; A. El Alaoui; L. El Fassi; L. Elouadrhiri; P. Eugenio; D. I. Glazier; S. M. Hughes; D. Sokhan; I. Stankovic; D. P. Watts; N. Zachariou

doi:10.1103/PhysRevC.95.035207

Target and beam-target spin asymmetries in exclusive pion electroproduction for Q(2) > 1 GeV2. II. ep -> e pi(0) p

CLAS Collaboration, P. E. Bosted^*, A. Kim, K. P. Adhikari, D. Adikaram, Z. Akbar, M. J. Amaryan, S. Anefalos Pereira, H. Avakian, R. A. Badui, J. Ball, I. Balossino, M. Battaglieri, I. Bedlinskiy, A. S. Biselli, S. Boiarinov, W. J. Briscoe, W. K. Brooks, S. Bultmann, V. D. BurkertT. Cao, D. S. Carman, A. Celentano, S. Chandavar, G. Charles, T. Chetry, G. Ciullo, L. Clark, L. Colaneri, P. L. Cole, M. Contalbrigo, O. Cortes, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, E. De Sanctis, A. Deur, C. Djalali, R. Dupre, H. Egiyan, A. El Alaoui, L. El Fassi, L. Elouadrhiri, P. Eugenio, D. I. Glazier, S. M. Hughes, D. Sokhan, I. Stankovic, D. P. Watts, N. Zachariou

^*Corresponding author for this work

School of Physics and Astronomy

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

Abstract

Beam-target double-spin asymmetries and target single-spin asymmetries were measured for the exclusive pi(0) electroproduction reaction. gamma(*) p -> p pi(0), expanding an analysis of the. gamma(*) p -> n pi(+) reaction from the same experiment. The results were obtained from scattering of 6-GeV longitudinally polarized electrons off longitudinally polarized protons using the CEBAF Large Acceptance Spectrometer at Jefferson Laboratory. The kinematic ranges covered are 1.1 <W <3 GeV and 1 <Q(2) <6 GeV2. Results were obtained for about 5700 bins in W, Q(2), cos(theta(*)), and phi(*). The beam-target asymmetries were found to generally be greater than zero, with relatively modest phi(*) dependence. The target asymmetries exhibit very strong phi(*) dependence, with a change in sign occurring between results at low W and high W, in contrast to pi(+) electroproduction. Reasonable agreement is found with phenomenological fits to previous data for W <1.6 GeV, but significant differences are seen at higherW. When combined with cross-sectional measurements, as well as pi(+) observables, the present results will provide powerful constraints on nucleon resonance amplitudes at moderate and large values of Q(2), for resonances with masses as high as 2.4 GeV.

Original language	English
Article number	035207
Number of pages	12
Journal	Physical Review C
Volume	95
Issue number	3
DOIs	https://doi.org/10.1103/PhysRevC.95.035207
Publication status	Published - 20 Mar 2017

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RESONANCE

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10.1103/PhysRevC.95.035207

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CLAS Collaboration, Bosted, P. E., Kim, A., Adhikari, K. P., Adikaram, D., Akbar, Z., Amaryan, M. J., Pereira, S. A., Avakian, H., Badui, R. A., Ball, J., Balossino, I., Battaglieri, M., Bedlinskiy, I., Biselli, A. S., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Bultmann, S., ... Zachariou, N. (2017). Target and beam-target spin asymmetries in exclusive pion electroproduction for Q(2) > 1 GeV2. II. ep -> e pi(0) p. Physical Review C, 95(3), Article 035207. https://doi.org/10.1103/PhysRevC.95.035207

@article{9cd47df8ae624b188a15de84bccc2329,

title = "Target and beam-target spin asymmetries in exclusive pion electroproduction for Q(2) > 1 GeV2. II. ep -> e pi(0) p",

abstract = "Beam-target double-spin asymmetries and target single-spin asymmetries were measured for the exclusive pi(0) electroproduction reaction. gamma(*) p -> p pi(0), expanding an analysis of the. gamma(*) p -> n pi(+) reaction from the same experiment. The results were obtained from scattering of 6-GeV longitudinally polarized electrons off longitudinally polarized protons using the CEBAF Large Acceptance Spectrometer at Jefferson Laboratory. The kinematic ranges covered are 1.1 <W <3 GeV and 1 <Q(2) <6 GeV2. Results were obtained for about 5700 bins in W, Q(2), cos(theta(*)), and phi(*). The beam-target asymmetries were found to generally be greater than zero, with relatively modest phi(*) dependence. The target asymmetries exhibit very strong phi(*) dependence, with a change in sign occurring between results at low W and high W, in contrast to pi(+) electroproduction. Reasonable agreement is found with phenomenological fits to previous data for W <1.6 GeV, but significant differences are seen at higherW. When combined with cross-sectional measurements, as well as pi(+) observables, the present results will provide powerful constraints on nucleon resonance amplitudes at moderate and large values of Q(2), for resonances with masses as high as 2.4 GeV.",

keywords = "RESONANCE",

author = "{CLAS Collaboration} and Bosted, {P. E.} and A. Kim and Adhikari, {K. P.} and D. Adikaram and Z. Akbar and Amaryan, {M. J.} and Pereira, {S. Anefalos} and H. Avakian and Badui, {R. A.} and J. Ball and I. Balossino and M. Battaglieri and I. Bedlinskiy and Biselli, {A. S.} and S. Boiarinov and Briscoe, {W. J.} and Brooks, {W. K.} and S. Bultmann and Burkert, {V. D.} and T. Cao and Carman, {D. S.} and A. Celentano and S. Chandavar and G. Charles and T. Chetry and G. Ciullo and L. Clark and L. Colaneri and Cole, {P. L.} and M. Contalbrigo and O. Cortes and V. Crede and A. D'Angelo and N. Dashyan and {De Vita}, R. and {De Sanctis}, E. and A. Deur and C. Djalali and R. Dupre and H. Egiyan and {El Alaoui}, A. and {El Fassi}, L. and L. Elouadrhiri and P. Eugenio and Glazier, {D. I.} and Hughes, {S. M.} and D. Sokhan and I. Stankovic and Watts, {D. P.} and N. Zachariou",

year = "2017",

month = mar,

day = "20",

doi = "10.1103/PhysRevC.95.035207",

language = "English",

volume = "95",

journal = "Physical Review C",

issn = "2469-9985",

publisher = "American Physical Society",

number = "3",

}

CLAS Collaboration, Bosted, PE, Kim, A, Adhikari, KP, Adikaram, D, Akbar, Z, Amaryan, MJ, Pereira, SA, Avakian, H, Badui, RA, Ball, J, Balossino, I, Battaglieri, M, Bedlinskiy, I, Biselli, AS, Boiarinov, S, Briscoe, WJ, Brooks, WK, Bultmann, S, Burkert, VD, Cao, T, Carman, DS, Celentano, A, Chandavar, S, Charles, G, Chetry, T, Ciullo, G, Clark, L, Colaneri, L, Cole, PL, Contalbrigo, M, Cortes, O, Crede, V, D'Angelo, A, Dashyan, N, De Vita, R, De Sanctis, E, Deur, A, Djalali, C, Dupre, R, Egiyan, H, El Alaoui, A, El Fassi, L, Elouadrhiri, L, Eugenio, P, Glazier, DI, Hughes, SM, Sokhan, D, Stankovic, I, Watts, DP & Zachariou, N 2017, 'Target and beam-target spin asymmetries in exclusive pion electroproduction for Q(2) > 1 GeV2. II. ep -> e pi(0) p', Physical Review C, vol. 95, no. 3, 035207. https://doi.org/10.1103/PhysRevC.95.035207

TY - JOUR

T1 - Target and beam-target spin asymmetries in exclusive pion electroproduction for Q(2) > 1 GeV2. II. ep -> e pi(0) p

AU - CLAS Collaboration

AU - Bosted, P. E.

AU - Kim, A.

AU - Adhikari, K. P.

AU - Adikaram, D.

AU - Akbar, Z.

AU - Amaryan, M. J.

AU - Pereira, S. Anefalos

AU - Avakian, H.

AU - Badui, R. A.

AU - Ball, J.

AU - Balossino, I.

AU - Battaglieri, M.

AU - Bedlinskiy, I.

AU - Biselli, A. S.

AU - Boiarinov, S.

AU - Briscoe, W. J.

AU - Brooks, W. K.

AU - Bultmann, S.

AU - Burkert, V. D.

AU - Cao, T.

AU - Carman, D. S.

AU - Celentano, A.

AU - Chandavar, S.

AU - Charles, G.

AU - Chetry, T.

AU - Ciullo, G.

AU - Clark, L.

AU - Colaneri, L.

AU - Cole, P. L.

AU - Contalbrigo, M.

AU - Cortes, O.

AU - Crede, V.

AU - D'Angelo, A.

AU - Dashyan, N.

AU - De Vita, R.

AU - De Sanctis, E.

AU - Deur, A.

AU - Djalali, C.

AU - Dupre, R.

AU - Egiyan, H.

AU - El Alaoui, A.

AU - El Fassi, L.

AU - Elouadrhiri, L.

AU - Eugenio, P.

AU - Glazier, D. I.

AU - Hughes, S. M.

AU - Sokhan, D.

AU - Stankovic, I.

AU - Watts, D. P.

AU - Zachariou, N.

PY - 2017/3/20

Y1 - 2017/3/20

N2 - Beam-target double-spin asymmetries and target single-spin asymmetries were measured for the exclusive pi(0) electroproduction reaction. gamma(*) p -> p pi(0), expanding an analysis of the. gamma(*) p -> n pi(+) reaction from the same experiment. The results were obtained from scattering of 6-GeV longitudinally polarized electrons off longitudinally polarized protons using the CEBAF Large Acceptance Spectrometer at Jefferson Laboratory. The kinematic ranges covered are 1.1 <W <3 GeV and 1 <Q(2) <6 GeV2. Results were obtained for about 5700 bins in W, Q(2), cos(theta(*)), and phi(*). The beam-target asymmetries were found to generally be greater than zero, with relatively modest phi(*) dependence. The target asymmetries exhibit very strong phi(*) dependence, with a change in sign occurring between results at low W and high W, in contrast to pi(+) electroproduction. Reasonable agreement is found with phenomenological fits to previous data for W <1.6 GeV, but significant differences are seen at higherW. When combined with cross-sectional measurements, as well as pi(+) observables, the present results will provide powerful constraints on nucleon resonance amplitudes at moderate and large values of Q(2), for resonances with masses as high as 2.4 GeV.

AB - Beam-target double-spin asymmetries and target single-spin asymmetries were measured for the exclusive pi(0) electroproduction reaction. gamma(*) p -> p pi(0), expanding an analysis of the. gamma(*) p -> n pi(+) reaction from the same experiment. The results were obtained from scattering of 6-GeV longitudinally polarized electrons off longitudinally polarized protons using the CEBAF Large Acceptance Spectrometer at Jefferson Laboratory. The kinematic ranges covered are 1.1 <W <3 GeV and 1 <Q(2) <6 GeV2. Results were obtained for about 5700 bins in W, Q(2), cos(theta(*)), and phi(*). The beam-target asymmetries were found to generally be greater than zero, with relatively modest phi(*) dependence. The target asymmetries exhibit very strong phi(*) dependence, with a change in sign occurring between results at low W and high W, in contrast to pi(+) electroproduction. Reasonable agreement is found with phenomenological fits to previous data for W <1.6 GeV, but significant differences are seen at higherW. When combined with cross-sectional measurements, as well as pi(+) observables, the present results will provide powerful constraints on nucleon resonance amplitudes at moderate and large values of Q(2), for resonances with masses as high as 2.4 GeV.

KW - RESONANCE

UR - http://eprints.gla.ac.uk/139294/

U2 - 10.1103/PhysRevC.95.035207

DO - 10.1103/PhysRevC.95.035207

M3 - Article

SN - 2469-9985

VL - 95

JO - Physical Review C

JF - Physical Review C

IS - 3

M1 - 035207

ER -

Target and beam-target spin asymmetries in exclusive pion electroproduction for Q(2) > 1 GeV2. II. ep -> e pi(0) p

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