title: Longitudinal target-spin asymmetries for deeply virtual compton scattering.
abstract: A measurement of the electroproduction of photons off protons in the deeply inelastic regime was performed at Jefferson Lab using a nearly 6 GeV electron beam, a longitudinally polarized proton target, and the CEBAF Large Acceptance Spectrometer. Target-spin asymmetries for ep→e^{'}p^{'}γ events, which arise from the interference of the deeply virtual Compton scattering and the Bethe-Heitler processes, were extracted over the widest kinematics in Q^{2}, x_{B}, t, and ϕ, for 166 four-dimensional bins. In the framework of generalized parton distributions, at leading twist the t dependence of these asymmetries provides insight into the spatial distribution of the axial charge of the proton, which appears to be concentrated in its center. These results also bring important and necessary constraints for the existing parametrizations of chiral-even generalized parton distributions.
authors: University of Connecticut, Storrs, Connecticut 06269, USA and CEA, Centre de Saclay, Irfu/Service de Physique Nucléaire, 91191 Gif-sur-Yvette, France.
authors: E
authors: E
authors: Seder
authors: Fairfield University, Fairfield, Connecticut 06824, USA.
authors: A
authors: A
authors: Biselli
authors: INFN, Laboratori Nazionali di Frascati, 00044 Frascati, Italy and Institut de Physique Nucléaire Orsay, 91406 Orsay, France.
authors: S
authors: S
authors: Pisano
authors: Institut de Physique Nucléaire Orsay, 91406 Orsay, France.
authors: S
authors: S
authors: Niccolai
authors: University of Glasgow, Glasgow G12 8QQ, United Kingdom and Edinburgh University, Edinburgh EH9 3JZ, United Kingdom.
authors: G D
authors: GD
authors: Smith
authors: University of Connecticut, Storrs, Connecticut 06269, USA.
authors: K
authors: K
authors: Joo
authors: Old Dominion University, Norfolk, Virginia 23529, USA.
authors: K
authors: K
authors: Adhikari
authors: Old Dominion University, Norfolk, Virginia 23529, USA.
authors: M J
authors: MJ
authors: Amaryan
authors: University of Glasgow, Glasgow G12 8QQ, United Kingdom.
authors: M D
authors: MD
authors: Anderson
authors: INFN, Laboratori Nazionali di Frascati, 00044 Frascati, Italy.
authors: S
authors: S
authors: Anefalos Pereira
authors: Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA.
authors: H
authors: H
authors: Avakian
authors: INFN, Sezione di Genova, 16146 Genova, Italy.
authors: M
authors: M
authors: Battaglieri
authors: Institute of Theoretical and Experimental Physics, Moscow 117259, Russia.
authors: I
authors: I
authors: Bedlinskiy
authors: Florida International University, Miami, Florida 33199, USA.
authors: J
authors: J
authors: Bono
authors: Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA.
authors: S
authors: S
authors: Boiarinov
authors: Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA and College of William and Mary, Williamsburg, Virginia 23187-8795, USA.
authors: P
authors: P
authors: Bosted
authors: The George Washington University, Washington, D.C. 20052, USA.
authors: W
authors: W
authors: Briscoe
authors: Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA.
authors: J
authors: J
authors: Brock
authors: Universidad Técnica Federico Santa María, Casilla 110-V Valparaíso, Chile.
authors: W K
authors: WK
authors: Brooks
authors: Old Dominion University, Norfolk, Virginia 23529, USA.
authors: S
authors: S
authors: Bültmann
authors: Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA.
authors: V D
authors: VD
authors: Burkert
authors: Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA.
authors: D S
authors: DS
authors: Carman
authors: Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA.
authors: C
authors: C
authors: Carlin
authors: INFN, Sezione di Genova, 16146 Genova, Italy.
authors: A
authors: A
authors: Celentano
authors: Ohio University, Athens, Ohio 45701, USA.
authors: S
authors: S
authors: Chandavar
authors: Institut de Physique Nucléaire Orsay, 91406 Orsay, France.
authors: G
authors: G
authors: Charles
authors: INFN, Sezione di Roma Tor Vergata, 00133 Roma, Italy.
authors: L
authors: L
authors: Colaneri
authors: Idaho State University, Pocatello, Idaho 83209, USA.
authors: P L
authors: PL
authors: Cole
authors: INFN, Sezione di Ferrara, 44100 Ferrara, Italy.
authors: M
authors: M
authors: Contalbrigo
authors: University of Virginia, Charlottesville, Virginia 22901, USA.
authors: D
authors: D
authors: Crabb
authors: University of Virginia, Charlottesville, Virginia 22901, USA.
authors: V
authors: V
authors: Crede
authors: INFN, Sezione di Roma Tor Vergata, 00133 Roma, Italy and Università di Roma Tor Vergata, 00133 Roma, Italy.
authors: A
authors: A
authors: D'Angelo
authors: Yerevan Physics Institute, 375036 Yerevan, Armenia.
authors: N
authors: N
authors: Dashyan
authors: INFN, Sezione di Genova, 16146 Genova, Italy.
authors: R
authors: R
authors: De Vita
authors: INFN, Laboratori Nazionali di Frascati, 00044 Frascati, Italy.
authors: E
authors: E
authors: De Sanctis
authors: Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA.
authors: A
authors: A
authors: Deur
authors: University of South Carolina, Columbia, South Carolina 29208, USA.
authors: C
authors: C
authors: Djalali
authors: Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA and Christopher Newport University, Newport News, Virginia 23606, USA.
authors: D
authors: D
authors: Doughty
authors: Institut de Physique Nucléaire Orsay, 91406 Orsay, France and Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors: R
authors: R
authors: Dupre
authors: Old Dominion University, Norfolk, Virginia 23529, USA.
authors: L
authors: L
authors: El Fassi
authors: Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA.
authors: L
authors: L
authors: Elouadrhiri
authors: Florida State University, Tallahassee, Florida 32306, USA.
authors: P
authors: P
authors: Eugenio
authors: University of South Carolina, Columbia, South Carolina 29208, USA and Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, 119234 Moscow, Russia.
authors: G
authors: G
authors: Fedotov
authors: University of Glasgow, Glasgow G12 8QQ, United Kingdom and INFN, Sezione di Genova, 16146 Genova, Italy.
authors: S
authors: S
authors: Fegan
authors: INFN, Sezione di Torino, Torino, Italy.
authors: A
authors: A
authors: Filippi
authors: Edinburgh University, Edinburgh EH9 3JZ, United Kingdom.
authors: J A
authors: JA
authors: Fleming
authors: Institut de Physique Nucléaire Orsay, 91406 Orsay, France.
authors: A
authors: A
authors: Fradi
authors: Institut de Physique Nucléaire Orsay, 91406 Orsay, France.
authors: B
authors: B
authors: Garillon
authors: CEA, Centre de Saclay, Irfu/Service de Physique Nucléaire, 91191 Gif-sur-Yvette, France.
authors: M
authors: M
authors: Garçon
authors: Yerevan Physics Institute, 375036 Yerevan, Armenia.
authors: N
authors: N
authors: Gevorgyan
authors: Yerevan Physics Institute, 375036 Yerevan, Armenia.
authors: Y
authors: Y
authors: Ghandilyan
authors: James Madison University, Harrisonburg, Virginia 22807, USA.
authors: K L
authors: KL
authors: Giovanetti
authors: CEA, Centre de Saclay, Irfu/Service de Physique Nucléaire, 91191 Gif-sur-Yvette, France and Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA.
authors: F X
authors: FX
authors: Girod
authors: Ohio University, Athens, Ohio 45701, USA.
authors: J T
authors: JT
authors: Goetz
authors: University of Connecticut, Storrs, Connecticut 06269, USA.
authors: W
authors: W
authors: Gohn
authors: University of South Carolina, Columbia, South Carolina 29208, USA.
authors: R W
authors: RW
authors: Gothe
authors: College of William and Mary, Williamsburg, Virginia 23187-8795, USA.
authors: K A
authors: KA
authors: Griffioen
authors: Institut de Physique Nucléaire Orsay, 91406 Orsay, France.
authors: B
authors: B
authors: Guegan
authors: Institut de Physique Nucléaire Orsay, 91406 Orsay, France.
authors: M
authors: M
authors: Guidal
authors: Florida International University, Miami, Florida 33199, USA.
authors: L
authors: L
authors: Guo
authors: Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors: K
authors: K
authors: Hafidi
authors: Universidad Técnica Federico Santa María, Casilla 110-V Valparaíso, Chile and Yerevan Physics Institute, 375036 Yerevan, Armenia.
authors: H
authors: H
authors: Hakobyan
authors: University of Virginia, Charlottesville, Virginia 22901, USA.
authors: C
authors: C
authors: Hanretty
authors: University of Connecticut, Storrs, Connecticut 06269, USA.
authors: N
authors: N
authors: Harrison
authors: Institut de Physique Nucléaire Orsay, 91406 Orsay, France.
authors: M
authors: M
authors: Hattawy
authors: Rensselaer Polytechnic Institute, Troy, New York 12180-3590, USA.
authors: N
authors: N
authors: Hirlinger Saylor
authors: University of New Hampshire, Durham, New Hampshire 03824-3568, USA.
authors: M
authors: M
authors: Holtrop
authors: Edinburgh University, Edinburgh EH9 3JZ, United Kingdom.
authors: S M
authors: SM
authors: Hughes
authors: University of South Carolina, Columbia, South Carolina 29208, USA.
authors: Y
authors: Y
authors: Ilieva
authors: University of Glasgow, Glasgow G12 8QQ, United Kingdom.
authors: D G
authors: DG
authors: Ireland
authors: Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, 119234 Moscow, Russia.
authors: B S
authors: BS
authors: Ishkhanov
authors: Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, 119234 Moscow, Russia.
authors: E L
authors: EL
authors: Isupov
authors: Institut de Physique Nucléaire Orsay, 91406 Orsay, France.
authors: H S
authors: HS
authors: Jo
authors: Temple University, Philadelphia, Pennsylvania 19122, USA.
authors: S
authors: S
authors: Joosten
authors: Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA.
authors: C D
authors: CD
authors: Keith
authors: Ohio University, Athens, Ohio 45701, USA and University of Virginia, Charlottesville, Virginia 22901, USA.
authors: D
authors: D
authors: Keller
authors: Yerevan Physics Institute, 375036 Yerevan, Armenia.
authors: G
authors: G
authors: Khachatryan
authors: Idaho State University, Pocatello, Idaho 83209, USA and Norfolk State University, Norfolk, Virginia 23504, USA.
authors: M
authors: M
authors: Khandaker
authors: Kyungpook National University, Daegu 702-701, Republic of Korea.
authors: A
authors: A
authors: Kim
authors: Kyungpook National University, Daegu 702-701, Republic of Korea.
authors: W
authors: W
authors: Kim
authors: Old Dominion University, Norfolk, Virginia 23529, USA.
authors: A
authors: A
authors: Klein
authors: Catholic University of America, Washington, D.C. 20064, USA.
authors: F J
authors: FJ
authors: Klein
authors: Old Dominion University, Norfolk, Virginia 23529, USA.
authors: S
authors: S
authors: Koirala
authors: Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA.
authors: V
authors: V
authors: Kubarovsky
authors: Old Dominion University, Norfolk, Virginia 23529, USA.
authors: S E
authors: SE
authors: Kuhn
authors: INFN, Sezione di Ferrara, 44100 Ferrara, Italy.
authors: P
authors: P
authors: Lenisa
authors: University of Glasgow, Glasgow G12 8QQ, United Kingdom.
authors: K
authors: K
authors: Livingston
authors: University of South Carolina, Columbia, South Carolina 29208, USA.
authors: H Y
authors: HY
authors: Lu
authors: University of Glasgow, Glasgow G12 8QQ, United Kingdom.
authors: I J D
authors: IJ
authors: MacGregor
authors: University of Connecticut, Storrs, Connecticut 06269, USA.
authors: N
authors: N
authors: Markov
authors: Old Dominion University, Norfolk, Virginia 23529, USA.
authors: M
authors: M
authors: Mayer
authors: University of Glasgow, Glasgow G12 8QQ, United Kingdom.
authors: B
authors: B
authors: McKinnon
authors: Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA.
authors: D G
authors: DG
authors: Meekins
authors: University of Connecticut, Storrs, Connecticut 06269, USA.
authors: T
authors: T
authors: Mineeva
authors: INFN, Laboratori Nazionali di Frascati, 00044 Frascati, Italy.
authors: M
authors: M
authors: Mirazita
authors: Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA and Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, 119234 Moscow, Russia.
authors: V
authors: V
authors: Mokeev
authors: INFN, Laboratori Nazionali di Frascati, 00044 Frascati, Italy.
authors: R
authors: R
authors: Montgomery
authors: Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors: C I
authors: CI
authors: Moody
authors: CEA, Centre de Saclay, Irfu/Service de Physique Nucléaire, 91191 Gif-sur-Yvette, France.
authors: H
authors: H
authors: Moutarde
authors: INFN, Sezione di Ferrara, 44100 Ferrara, Italy.
authors: A
authors: A
authors: Movsisyan
authors: Institut de Physique Nucléaire Orsay, 91406 Orsay, France.
authors: C
authors: C
authors: Munoz Camacho
authors: Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA and Catholic University of America, Washington, D.C. 20064, USA.
authors: P
authors: P
authors: Nadel-Turonski
authors: James Madison University, Harrisonburg, Virginia 22807, USA.
authors: I
authors: I
authors: Niculescu
authors: INFN, Sezione di Genova, 16146 Genova, Italy.
authors: M
authors: M
authors: Osipenko
authors: Florida State University, Tallahassee, Florida 32306, USA.
authors: A I
authors: AI
authors: Ostrovidov
authors: Temple University, Philadelphia, Pennsylvania 19122, USA.
authors: M
authors: M
authors: Paolone
authors: INFN, Sezione di Ferrara, 44100 Ferrara, Italy.
authors: L L
authors: LL
authors: Pappalardo
authors: Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA and University of South Carolina, Columbia, South Carolina 29208, USA.
authors: K
authors: K
authors: Park
authors: Florida State University, Tallahassee, Florida 32306, USA.
authors: S
authors: S
authors: Park
authors: Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA and Arizona State University, Tempe, Arizona 85287-1504, USA.
authors: E
authors: E
authors: Pasyuk
authors: University of Virginia, Charlottesville, Virginia 22901, USA.
authors: P
authors: P
authors: Peng
authors: Florida International University, Miami, Florida 33199, USA.
authors: W
authors: W
authors: Phelps
authors: Institute of Theoretical and Experimental Physics, Moscow 117259, Russia.
authors: O
authors: O
authors: Pogorelko
authors: California State University, Dominguez Hills, Carson, California 90747, USA.
authors: J W
authors: JW
authors: Price
authors: Old Dominion University, Norfolk, Virginia 23529, USA.
authors: Y
authors: Y
authors: Prok
authors: University of Glasgow, Glasgow G12 8QQ, United Kingdom.
authors: D
authors: D
authors: Protopopescu
authors: University of Connecticut, Storrs, Connecticut 06269, USA.
authors: A J R
authors: AJ
authors: Puckett
authors: INFN, Sezione di Genova, 16146 Genova, Italy.
authors: M
authors: M
authors: Ripani
authors: INFN, Sezione di Roma Tor Vergata, 00133 Roma, Italy.
authors: A
authors: A
authors: Rizzo
authors: University of Glasgow, Glasgow G12 8QQ, United Kingdom.
authors: G
authors: G
authors: Rosner
authors: INFN, Laboratori Nazionali di Frascati, 00044 Frascati, Italy and Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA.
authors: P
authors: P
authors: Rossi
authors: Florida State University, Tallahassee, Florida 32306, USA.
authors: P
authors: P
authors: Roy
authors: CEA, Centre de Saclay, Irfu/Service de Physique Nucléaire, 91191 Gif-sur-Yvette, France.
authors: F
authors: F
authors: Sabatié
authors: Norfolk State University, Norfolk, Virginia 23504, USA.
authors: C
authors: C
authors: Salgado
authors: Florida International University, Miami, Florida 33199, USA and The George Washington University, Washington, D.C. 20052, USA.
authors: D
authors: D
authors: Schott
authors: Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.
authors: R A
authors: RA
authors: Schumacher
authors: Arizona State University, Tempe, Arizona 85287-1504, USA.
authors: I
authors: I
authors: Senderovich
authors: Yerevan Physics Institute, 375036 Yerevan, Armenia.
authors: A
authors: A
authors: Simonyan
authors: University of South Carolina, Columbia, South Carolina 29208, USA.
authors: I
authors: I
authors: Skorodumina
authors: University of Glasgow, Glasgow G12 8QQ, United Kingdom and Edinburgh University, Edinburgh EH9 3JZ, United Kingdom.
authors: D
authors: D
authors: Sokhan
authors: Temple University, Philadelphia, Pennsylvania 19122, USA.
authors: N
authors: N
authors: Sparveris
authors: Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA.
authors: S
authors: S
authors: Stepanyan
authors: Rensselaer Polytechnic Institute, Troy, New York 12180-3590, USA.
authors: P
authors: P
authors: Stoler
authors: The George Washington University, Washington, D.C. 20052, USA.
authors: I I
authors: II
authors: Strakovsky
authors: University of South Carolina, Columbia, South Carolina 29208, USA.
authors: S
authors: S
authors: Strauch
authors: Universidad Técnica Federico Santa María, Casilla 110-V Valparaíso, Chile.
authors: V
authors: V
authors: Sytnik
authors: INFN, Sezione di Genova, 16146 Genova, Italy and Università di Genova, 16146 Genova, Italy.
authors: M
authors: M
authors: Taiuti
authors: Ohio University, Athens, Ohio 45701, USA.
authors: W
authors: W
authors: Tang
authors: University of South Carolina, Columbia, South Carolina 29208, USA.
authors: Y
authors: Y
authors: Tian
authors: University of Connecticut, Storrs, Connecticut 06269, USA and Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA.
authors: M
authors: M
authors: Ungaro
authors: Yerevan Physics Institute, 375036 Yerevan, Armenia.
authors: H
authors: H
authors: Voskanyan
authors: LPSC, Université Grenoble-Alps, CNRS/IN2P3, Grenoble, France.
authors: E
authors: E
authors: Voutier
authors: Catholic University of America, Washington, D.C. 20064, USA.
authors: N K
authors: NK
authors: Walford
authors: Edinburgh University, Edinburgh EH9 3JZ, United Kingdom.
authors: D P
authors: DP
authors: Watts
authors: Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA.
authors: X
authors: X
authors: Wei
authors: Old Dominion University, Norfolk, Virginia 23529, USA.
authors: L B
authors: LB
authors: Weinstein
authors: University of South Carolina, Columbia, South Carolina 29208, USA and Canisius College, Buffalo, New York 14208, USA.
authors: M H
authors: MH
authors: Wood
authors: University of South Carolina, Columbia, South Carolina 29208, USA.
authors: N
authors: N
authors: Zachariou
authors: Edinburgh University, Edinburgh EH9 3JZ, United Kingdom.
authors: L
authors: L
authors: Zana
authors: Old Dominion University, Norfolk, Virginia 23529, USA and Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA.
authors: J
authors: J
authors: Zhang
authors: INFN, Sezione di Roma Tor Vergata, 00133 Roma, Italy.
authors: I
authors: I
authors: Zonta