First Measurement of Timelike Compton Scattering

P Chatagnon¹, S Niccolai¹, S Stepanyan², M J Amaryan³, G Angelini⁴, W R Armstrong⁵, H Atac⁶, C Ayerbe Gayoso⁷, N A Baltzell², L Barion⁸, M Bashkanov⁹, M Battaglieri^{10

2}, I Bedlinskiy¹¹, F Benmokhtar¹², A Bianconi^{13

14}, L Biondo^{10

15

16}, A S Biselli¹⁷, M Bondi¹⁰, F Bossù¹⁸, S Boiarinov², W J Briscoe⁴, W K Brooks^{2

19}, D Bulumulla³, V D Burkert², D S Carman², J C Carvajal²⁰, M Caudron¹, A Celentano¹⁰, T Chetry^{21

22}, G Ciullo^{23

8}, L Clark²⁴, P L Cole²⁵, M Contalbrigo⁸, G Costantini^{13

14}, V Crede²⁶, A D'Angelo^{27

28}, N Dashyan²⁹, M Defurne¹⁸, R De Vita¹⁰, A Deur², S Diehl^{30

31}, C Djalali²², R Dupré¹, H Egiyan², M Ehrhart¹, A El Alaoui¹⁹, L El Fassi²¹, L Elouadrhiri², S Fegan⁹, R Fersch³², A Filippi³³, G Gavalian², Y Ghandilyan²⁹, G P Gilfoyle³⁴, F X Girod², D I Glazier²⁴, A A Golubenko³⁵, R W Gothe³⁶, Y Gotra², K A Griffioen⁷, M Guidal¹, L Guo²⁰, H Hakobyan^{19

29}, M Hattawy³, T B Hayward^{30

7}, D Heddle^{32

2}, A Hobart¹, M Holtrop³⁷, C E Hyde³, Y Ilieva³⁶, D G Ireland²⁴, E L Isupov³⁵, H S Jo³⁸, K Joo³⁰, M L Kabir²¹, D Keller³⁹, G Khachatryan²⁹, A Khanal²⁰, A Kim³⁰, W Kim³⁸, A Kripko³¹, V Kubarovsky², S E Kuhn³, L Lanza²⁷, M Leali^{13

14}, S Lee⁴⁰, P Lenisa^{23

8}, K Livingston²⁴, I J D MacGregor²⁴, D Marchand¹, L Marsicano¹⁰, V Mascagna^{13

41}, B McKinnon²⁴, C McLauchlin³⁶, S Migliorati^{13

14}, M Mirazita⁴², V Mokeev², R A Montgomery²⁴, C Munoz Camacho¹, P Nadel-Turonski², P Naidoo²⁴, K Neupane³⁶, T R O'Connell³⁰, M Osipenko¹⁰, M Ouillon¹, P Pandey³, M Paolone^{43

6}, L L Pappalardo^{23

8}, R Paremuzyan^{37

2}, E Pasyuk², W Phelps^{32

4}, O Pogorelko¹¹, J Poudel³, J W Price⁴⁴, Y Prok³, B A Raue²⁰, T Reed²⁰, M Ripani¹⁰, A Rizzo^{27

28}, P Rossi², J Rowley²², F Sabatié¹⁸, A Schmidt⁴, E P Segarra⁴⁰, Y G Sharabian², E V Shirokov³⁵, U Shrestha^{30

22}, D Sokhan^{18

24}, O Soto^{42

19}, N Sparveris⁶, I I Strakovsky⁴, S Strauch³⁶, N Tyler³⁶, R Tyson²⁴, M Ungaro², S Vallarino⁸, L Venturelli^{13

14}, H Voskanyan²⁹, A Vossen^{45

2}, E Voutier¹, D P Watts⁹, K Wei³⁰, X Wei², R Wishart²⁴, B Yale⁷, N Zachariou⁹, J Zhang³⁹, Z W Zhao⁴⁵; CLAS Collaboration

Affiliations

¹ Université Paris-Saclay, CNRS/IN2P3, IJCLab, 91405 Orsay, France.
² Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA.
³ Old Dominion University, Norfolk, Virginia 23529, USA.
⁴ The George Washington University, Washington, D.C. 20052, USA.
⁵ Argonne National Laboratory, Argonne, Illinois 60439, USA.
⁶ Temple University, Philadelphia, Pennsylvania 19122, USA.
⁷ College of William and Mary, Williamsburg, Virginia 23187-8795, USA.
⁸ INFN, Sezione di Ferrara, 44100 Ferrara, Italy.
⁹ University of York, York YO10 5DD, United Kingdom.
¹⁰ INFN, Sezione di Genova, 16146 Genova, Italy.
¹¹ National Research Centre Kurchatov Institute-ITEP, Moscow, 117259, Russia.
¹² Duquesne University, 600 Forbes Avenue, Pittsburgh, Pennsylvania 15282, USA.
¹³ INFN, Sezione di Pavia, 27100 Pavia, Italy.
¹⁴ Università degli Studi di Brescia, 25123 Brescia, Italy.
¹⁵ INFN, Sezione di Catania, 95123 Catania, Italy.
¹⁶ Universit'a degli Studi di Messina, 98166 Messina, Italy.
¹⁷ Fairfield University, Fairfield, Connecticut 06824, USA.
¹⁸ IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France.
¹⁹ Universidad Técnica Federico Santa María, Casilla 110-V Valparaíso, Chile.
²⁰ Florida International University, Miami, Florida 33199, USA.
²¹ Mississippi State University, Mississippi State, Mississippi 39762-5167, USA.
²² Ohio University, Athens, Ohio 45701, USA.
²³ Universita' di Ferrara, 44121 Ferrara, Italy.
²⁴ University of Glasgow, Glasgow G12 8QQ, United Kingdom.
²⁵ Lamar University, 4400 M. L. King, Jr. Boulevard, P.O. Box 10046, Beaumont, Texas 77710, USA.
²⁶ Florida State University, Tallahassee, Florida 32306, USA.
²⁷ INFN, Sezione di Roma Tor Vergata, 00133 Rome, Italy.
²⁸ Universita' di Roma Tor Vergata, 00133 Rome, Italy.
²⁹ Yerevan Physics Institute, 375036 Yerevan, Armenia.
³⁰ University of Connecticut, Storrs, Connecticut 06269, USA.
³¹ II Physikalisches Institut der Universitaet Giessen, 35392 Giessen, Germany.
³² Christopher Newport University, Newport News, Virginia 23606, USA.
³³ INFN, Sezione di Torino, 10125 Torino, Italy.
³⁴ University of Richmond, Richmond, Virginia 23173, USA.
³⁵ Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, 119234 Moscow, Russia.
³⁶ University of South Carolina, Columbia, South Carolina 29208, USA.
³⁷ University of New Hampshire, Durham, New Hampshire 03824-3568, USA.
³⁸ Kyungpook National University, Daegu 41566, Republic of Korea.
³⁹ University of Virginia, Charlottesville, Virginia 22901, USA.
⁴⁰ Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307, USA.
⁴¹ Università degli Studi dell'Insubria, 22100 Como, Italy.
⁴² INFN, Laboratori Nazionali di Frascati, 00044 Frascati, Italy.
⁴³ New Mexico State University, P.O. Box 30001, Las Cruces, New Mexico 88003, USA.
⁴⁴ California State University, Dominguez Hills, Carson, California 90747, USA.
⁴⁵ Duke University, Durham, North Carolina 27708-0305, USA.

PMID: 35029502
DOI: 10.1103/PhysRevLett.127.262501

Free article

First Measurement of Timelike Compton Scattering

P Chatagnon et al. Phys Rev Lett. 2021.

Free article

. 2021 Dec 24;127(26):262501.

doi: 10.1103/PhysRevLett.127.262501.

Authors

Affiliations

¹ Université Paris-Saclay, CNRS/IN2P3, IJCLab, 91405 Orsay, France.
² Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA.
³ Old Dominion University, Norfolk, Virginia 23529, USA.
⁴ The George Washington University, Washington, D.C. 20052, USA.
⁵ Argonne National Laboratory, Argonne, Illinois 60439, USA.
⁶ Temple University, Philadelphia, Pennsylvania 19122, USA.
⁷ College of William and Mary, Williamsburg, Virginia 23187-8795, USA.
⁸ INFN, Sezione di Ferrara, 44100 Ferrara, Italy.
⁹ University of York, York YO10 5DD, United Kingdom.
¹⁰ INFN, Sezione di Genova, 16146 Genova, Italy.
¹¹ National Research Centre Kurchatov Institute-ITEP, Moscow, 117259, Russia.
¹² Duquesne University, 600 Forbes Avenue, Pittsburgh, Pennsylvania 15282, USA.
¹³ INFN, Sezione di Pavia, 27100 Pavia, Italy.
¹⁴ Università degli Studi di Brescia, 25123 Brescia, Italy.
¹⁵ INFN, Sezione di Catania, 95123 Catania, Italy.
¹⁶ Universit'a degli Studi di Messina, 98166 Messina, Italy.
¹⁷ Fairfield University, Fairfield, Connecticut 06824, USA.
¹⁸ IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France.
¹⁹ Universidad Técnica Federico Santa María, Casilla 110-V Valparaíso, Chile.
²⁰ Florida International University, Miami, Florida 33199, USA.
²¹ Mississippi State University, Mississippi State, Mississippi 39762-5167, USA.
²² Ohio University, Athens, Ohio 45701, USA.
²³ Universita' di Ferrara, 44121 Ferrara, Italy.
²⁴ University of Glasgow, Glasgow G12 8QQ, United Kingdom.
²⁵ Lamar University, 4400 M. L. King, Jr. Boulevard, P.O. Box 10046, Beaumont, Texas 77710, USA.
²⁶ Florida State University, Tallahassee, Florida 32306, USA.
²⁷ INFN, Sezione di Roma Tor Vergata, 00133 Rome, Italy.
²⁸ Universita' di Roma Tor Vergata, 00133 Rome, Italy.
²⁹ Yerevan Physics Institute, 375036 Yerevan, Armenia.
³⁰ University of Connecticut, Storrs, Connecticut 06269, USA.
³¹ II Physikalisches Institut der Universitaet Giessen, 35392 Giessen, Germany.
³² Christopher Newport University, Newport News, Virginia 23606, USA.
³³ INFN, Sezione di Torino, 10125 Torino, Italy.
³⁴ University of Richmond, Richmond, Virginia 23173, USA.
³⁵ Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, 119234 Moscow, Russia.
³⁶ University of South Carolina, Columbia, South Carolina 29208, USA.
³⁷ University of New Hampshire, Durham, New Hampshire 03824-3568, USA.
³⁸ Kyungpook National University, Daegu 41566, Republic of Korea.
³⁹ University of Virginia, Charlottesville, Virginia 22901, USA.
⁴⁰ Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307, USA.
⁴¹ Università degli Studi dell'Insubria, 22100 Como, Italy.
⁴² INFN, Laboratori Nazionali di Frascati, 00044 Frascati, Italy.
⁴³ New Mexico State University, P.O. Box 30001, Las Cruces, New Mexico 88003, USA.
⁴⁴ California State University, Dominguez Hills, Carson, California 90747, USA.
⁴⁵ Duke University, Durham, North Carolina 27708-0305, USA.

PMID: 35029502
DOI: 10.1103/PhysRevLett.127.262501

Abstract

We present the first measurement of the timelike Compton scattering process, γp→p^{'}γ^{*}(γ^{*}→e^{+}e^{-}), obtained with the CLAS12 detector at Jefferson Lab. The photon beam polarization and the decay lepton angular asymmetries are reported in the range of timelike photon virtualities 2.25<Q^{'2}<9 GeV^{2}, squared momentum transferred 0.1<-t<0.8 GeV^{2}, and average total center-of-mass energy squared s=14.5 GeV^{2}. The photon beam polarization asymmetry, similar to the beam-spin asymmetry in deep virtual Compton scattering, is sensitive to the imaginary part of the Compton form factors and provides a way to test the universality of the generalized parton distributions. The angular asymmetry of the decay leptons accesses the real part of the Compton form factors and thus the D-term in the parametrization of the generalized parton distributions.

PubMed Disclaimer

LinkOut - more resources

Full Text Sources
- American Physical Society
- White Rose Research Online
Miscellaneous
- NCI CPTAC Assay Portal

Save citation to file

Email citation

Add to Collections

Add to My Bibliography

Your saved search

Create a file for external citation management software

Your RSS Feed

First Measurement of Timelike Compton Scattering

Affiliations

First Measurement of Timelike Compton Scattering

Authors

Affiliations

Abstract

LinkOut - more resources

Full Text Sources

Miscellaneous