Extraction of beam-spin asymmetries from the hard exclusive $π^{+}$ channel off protons in a wide range of kinematics

(CLAS Collaboration)

doi:10.1103/PhysRevLett.125.182001

Extraction of beam-spin asymmetries from the hard exclusive $π^{+}$ channel off protons in a wide range of kinematics

(CLAS Collaboration)

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

Abstract

We have measured beam-spin asymmetries to extract the $\sin\phi$ moment $A_{LU}^{\sin\phi}$ from the hard exclusive $\vec{e} p \to e^\prime n \pi^+$ reaction above the resonance region, for the first time with nearly full coverage from forward to backward angles in the center-of-mass. The $A_{LU}^{\sin\phi}$ moment has been measured up to 6.6 GeV$^{2}$ in $-t$, covering the kinematic regimes of Generalized Parton Distributions (GPD) and baryon-to-meson Transition Distribution Amplitudes (TDA) at the same time. The experimental results in very forward kinematics demonstrate the sensitivity to chiral-odd and chiral-even GPDs. In very backward kinematics where the TDA framework is applicable, we found $A_{LU}^{\sin\phi}$ to be negative, while a sign change was observed near 90$^\circ$ in the center-of-mass. The unique results presented in this paper will provide critical constraints to establish reaction mechanisms that can help to further develop the GPD and TDA frameworks.

Original language	Undefined/Unknown
Article number	182001
Number of pages	7
Journal	Physical Review Letters
Volume	125
DOIs	https://doi.org/10.1103/PhysRevLett.125.182001
Publication status	Published - 28 Oct 2020

Bibliographical note

Keywords

nucl-ex
hep-ex
hep-ph

Access to Document

10.1103/PhysRevLett.125.182001

2007.15677v1
© 2020 American Physical Society. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details
Final published version, 1.09 MB

Nuclear Physics Consolidated Grant 2021-2024
Jenkins, D. (Principal investigator), Andreyev, A. (Co-investigator), Bashkanov, M. (Co-investigator), Bentley, M. (Co-investigator), Dobaczewski, J. J. (Co-investigator), Laird, A. M. (Co-investigator), Paschalis, S. (Co-investigator), Pastore, A. (Co-investigator), Petri, M. (Co-investigator), Wadsworth, R. (Co-investigator), Watts, D. (Co-investigator) & Zachariou, N. (Co-investigator)
SCIENCE AND TECHNOLOGY FACILITIES COUNCIL (STFC)
1/10/21 → 31/03/25
Project: Research project (funded) › Research

Cite this

@article{d5d7b13a82be45bfaf547d54a5ef9bb0,

title = "Extraction of beam-spin asymmetries from the hard exclusive $π^{+}$ channel off protons in a wide range of kinematics",

abstract = " We have measured beam-spin asymmetries to extract the $\sin\phi$ moment $A_{LU}^{\sin\phi}$ from the hard exclusive $\vec{e} p \to e^\prime n \pi^+$ reaction above the resonance region, for the first time with nearly full coverage from forward to backward angles in the center-of-mass. The $A_{LU}^{\sin\phi}$ moment has been measured up to 6.6 GeV$^{2}$ in $-t$, covering the kinematic regimes of Generalized Parton Distributions (GPD) and baryon-to-meson Transition Distribution Amplitudes (TDA) at the same time. The experimental results in very forward kinematics demonstrate the sensitivity to chiral-odd and chiral-even GPDs. In very backward kinematics where the TDA framework is applicable, we found $A_{LU}^{\sin\phi}$ to be negative, while a sign change was observed near 90$^\circ$ in the center-of-mass. The unique results presented in this paper will provide critical constraints to establish reaction mechanisms that can help to further develop the GPD and TDA frameworks. ",

keywords = "nucl-ex, hep-ex, hep-ph",

author = "{(CLAS Collaboration)} and S. Diehl and K. Joo and A. Kim and H. Avakian and P. Kroll and K. Park and D. Riser and K. Semenov-Tian-Shansky and K. Tezgin and Adhikari, {K. P.} and S. Adhikari and Amaryan, {M. J.} and G. Angelini and G. Asryan and H. Atac and L. Barion and M. Battaglieri and I. Bedlinskiy and F. Benmokhtar and A. Bianconi and Biselli, {A. S.} and F. Boss`u and S. Boiarinov and Briscoe, {W. J.} and Brooks, {W. K.} and D. Bulumulla and Burkert, {V. D.} and Carman, {D. S.} and Carvajal, {J. C.} and A. Celentano and P. Chatagnon and T. Chetry and G. Ciullo and L. Clark and Cole, {P. L.} and M. Contalbrigo and V. Crede and A. D'Angelo and N. Dashyan and Vita, {R. De} and M. Defurne and A. Deur and C. Dilks and C. Djalali and R. Dupre and H. Egiyan and M. Ehrhart and Alaoui, {A. El} and Watts, {D. P.} and N. Zachariou",

note = "{\textcopyright} 2020 American Physical Society. Uploaded in accordance with the publisher{\textquoteright}s self-archiving policy. Further copying may not be permitted; contact the publisher for details",

year = "2020",

month = oct,

day = "28",

doi = "10.1103/PhysRevLett.125.182001",

language = "Undefined/Unknown",

volume = "125",

journal = "Physical Review Letters",

issn = "0031-9007",

publisher = "American Physical Society",

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TY - JOUR

T1 - Extraction of beam-spin asymmetries from the hard exclusive $π^{+}$ channel off protons in a wide range of kinematics

AU - (CLAS Collaboration)

AU - Diehl, S.

AU - Joo, K.

AU - Kim, A.

AU - Avakian, H.

AU - Kroll, P.

AU - Park, K.

AU - Riser, D.

AU - Semenov-Tian-Shansky, K.

AU - Tezgin, K.

AU - Adhikari, K. P.

AU - Adhikari, S.

AU - Amaryan, M. J.

AU - Angelini, G.

AU - Asryan, G.

AU - Atac, H.

AU - Barion, L.

AU - Battaglieri, M.

AU - Bedlinskiy, I.

AU - Benmokhtar, F.

AU - Bianconi, A.

AU - Biselli, A. S.

AU - Boss`u, F.

AU - Boiarinov, S.

AU - Briscoe, W. J.

AU - Brooks, W. K.

AU - Bulumulla, D.

AU - Burkert, V. D.

AU - Carman, D. S.

AU - Carvajal, J. C.

AU - Celentano, A.

AU - Chatagnon, P.

AU - Chetry, T.

AU - Ciullo, G.

AU - Clark, L.

AU - Cole, P. L.

AU - Contalbrigo, M.

AU - Crede, V.

AU - D'Angelo, A.

AU - Dashyan, N.

AU - Vita, R. De

AU - Defurne, M.

AU - Deur, A.

AU - Dilks, C.

AU - Djalali, C.

AU - Dupre, R.

AU - Egiyan, H.

AU - Ehrhart, M.

AU - Alaoui, A. El

AU - Watts, D. P.

AU - Zachariou, N.

PY - 2020/10/28

Y1 - 2020/10/28

N2 - We have measured beam-spin asymmetries to extract the $\sin\phi$ moment $A_{LU}^{\sin\phi}$ from the hard exclusive $\vec{e} p \to e^\prime n \pi^+$ reaction above the resonance region, for the first time with nearly full coverage from forward to backward angles in the center-of-mass. The $A_{LU}^{\sin\phi}$ moment has been measured up to 6.6 GeV$^{2}$ in $-t$, covering the kinematic regimes of Generalized Parton Distributions (GPD) and baryon-to-meson Transition Distribution Amplitudes (TDA) at the same time. The experimental results in very forward kinematics demonstrate the sensitivity to chiral-odd and chiral-even GPDs. In very backward kinematics where the TDA framework is applicable, we found $A_{LU}^{\sin\phi}$ to be negative, while a sign change was observed near 90$^\circ$ in the center-of-mass. The unique results presented in this paper will provide critical constraints to establish reaction mechanisms that can help to further develop the GPD and TDA frameworks.

AB - We have measured beam-spin asymmetries to extract the $\sin\phi$ moment $A_{LU}^{\sin\phi}$ from the hard exclusive $\vec{e} p \to e^\prime n \pi^+$ reaction above the resonance region, for the first time with nearly full coverage from forward to backward angles in the center-of-mass. The $A_{LU}^{\sin\phi}$ moment has been measured up to 6.6 GeV$^{2}$ in $-t$, covering the kinematic regimes of Generalized Parton Distributions (GPD) and baryon-to-meson Transition Distribution Amplitudes (TDA) at the same time. The experimental results in very forward kinematics demonstrate the sensitivity to chiral-odd and chiral-even GPDs. In very backward kinematics where the TDA framework is applicable, we found $A_{LU}^{\sin\phi}$ to be negative, while a sign change was observed near 90$^\circ$ in the center-of-mass. The unique results presented in this paper will provide critical constraints to establish reaction mechanisms that can help to further develop the GPD and TDA frameworks.

KW - nucl-ex

KW - hep-ex

KW - hep-ph

U2 - 10.1103/PhysRevLett.125.182001

DO - 10.1103/PhysRevLett.125.182001

M3 - Article

SN - 0031-9007

VL - 125

JO - Physical Review Letters

JF - Physical Review Letters

M1 - 182001

ER -

Extraction of beam-spin asymmetries from the hard exclusive $π^{+}$ channel off protons in a wide range of kinematics

Abstract

Bibliographical note

Keywords

Access to Document

Projects

Nuclear Physics Consolidated Grant 2021-2024

Cite this