First Measurement of Near-Threshold and Subthreshold J/ψ Photoproduction off Nuclei

J R Pybus¹, L Ehinger¹, T Kolar², B Devkota³, P Sharp⁴, B Yu⁵, M M Dalton⁶, D Dutta³, H Gao⁵, O Hen¹, E Piasetzky², S N Santiesteban⁷, A Schmidt⁴, A Somov⁶, H Szumila-Vance⁶, S Adhikari⁸, A Asaturyan⁶, A Austregesilo⁶, C Ayerbe Gayoso³, J Barlow⁹, V V Berdnikov⁶, H D Bhatt³, D Bhetuwal³, T Black¹⁰, W J Briscoe⁴, G Chung¹¹, P L Cole¹², A Deur⁶, R Dotel¹³, H Egiyan⁶, P Eugenio⁹, C Fanelli¹⁴, L Gan¹⁰, A Gasparian¹⁵, J Guo¹⁶, K Hernandez¹⁷, D W Higinbotham⁶, P Hurck¹⁸, I Jaegle⁶, R T Jones¹⁹, V Kakoyan²⁰, A Karki³, H Li¹⁴, W B Li²¹, G R Linera⁹, V Lyubovitskij²², H Marukyan²⁰, M D McCaughan⁶, M McCracken²³, K Mizutani²⁴, D Nguyen²⁵, S Oresic²⁶, A I Ostrovidov⁹, Z Papandreou²⁶, C Paudel¹³, K Peters²⁷, J Ritman^{27

28}, A Schick²⁹, J Schwiening²⁷, A Smith⁶, S Somov³⁰, I Strakovsky⁴, K Suresh²⁶, V V Tarasov³¹, S Taylor⁶, T Xiao³², Z Zhang³³, X Zhou³³

Affiliations

¹ Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
² Tel Aviv University, School of Physics and Astronomy, Tel Aviv 69978, Israel.
³ Mississippi State University, Mississippi State, Mississippi 39762, USA.
⁴ The George Washington University, Washington, DC 20052, USA.
⁵ Duke University, and Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708, USA.
⁶ Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA.
⁷ University of New Hampshire, Durham, New Hampshire 03824, USA.
⁸ Old Dominion University, Norfolk, Virginia 23529, USA.
⁹ Florida State University, Tallahassee, Florida 32306, USA.
¹⁰ University of North Carolina Wilmington, Wilmington, North Carolina 28403, USA.
¹¹ Virginia Tech, Blacksburg, Virginia 24061, USA.
¹² Lamar University, Beaumont, Texas 77705, USA.
¹³ Florida International University, Miami, Florida 33199, USA.
¹⁴ College of William and Mary, Williamsburg, Virginia 23185, USA.
¹⁵ North Carolina Agricultural and Technical State University, Greensboro, North Carolina 27411, USA.
¹⁶ Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.
¹⁷ Arizona State University, Tempe, Arizona 85287, USA.
¹⁸ University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom.
¹⁹ University of Connecticut, Storrs, Connecticut 06269, USA.
²⁰ A. I. Alikhanyan National Science Laboratory (Yerevan Physics Institute), 0036, Yerevan, Armenia.
²¹ Stony Brook University, Stony Brook, New York 11794, USA.
²² Tomsk State University, 634050 Tomsk, Russia.
²³ Washington and Jefferson College, Washington, Pennsylvania 15301, USA.
²⁴ Osaka University, Osaka, Japan.
²⁵ The University of Tennessee, Knoxville, Tennessee 37996, USA.
²⁶ University of Regina, Regina, Saskatchewan S4S 0A2, Canada.
²⁷ GSI Helmholtz Centre for Heavy Ion Research, Darmstadt, Germany.
²⁸ Ruhr University Bochum, Bochum, Germany.
²⁹ University of Massachusetts Amherst, Amherst, Massachusetts 010031, USA.
³⁰ National Research Nuclear University MEPhI, Moscow 115409, Russia.
³¹ National Research Centre Kurchatov Institute, Moscow 123182, Russia.
³² University of North Texas, Denton, Texas 76201, USA.
³³ Wuhan University, Wuhan, Hubei, China.

PMID: 40479695
DOI: 10.1103/PhysRevLett.134.201903

First Measurement of Near-Threshold and Subthreshold J/ψ Photoproduction off Nuclei

J R Pybus et al. Phys Rev Lett. 2025.

. 2025 May 23;134(20):201903.

doi: 10.1103/PhysRevLett.134.201903.

Authors

Affiliations

¹ Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
² Tel Aviv University, School of Physics and Astronomy, Tel Aviv 69978, Israel.
³ Mississippi State University, Mississippi State, Mississippi 39762, USA.
⁴ The George Washington University, Washington, DC 20052, USA.
⁵ Duke University, and Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708, USA.
⁶ Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA.
⁷ University of New Hampshire, Durham, New Hampshire 03824, USA.
⁸ Old Dominion University, Norfolk, Virginia 23529, USA.
⁹ Florida State University, Tallahassee, Florida 32306, USA.
¹⁰ University of North Carolina Wilmington, Wilmington, North Carolina 28403, USA.
¹¹ Virginia Tech, Blacksburg, Virginia 24061, USA.
¹² Lamar University, Beaumont, Texas 77705, USA.
¹³ Florida International University, Miami, Florida 33199, USA.
¹⁴ College of William and Mary, Williamsburg, Virginia 23185, USA.
¹⁵ North Carolina Agricultural and Technical State University, Greensboro, North Carolina 27411, USA.
¹⁶ Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.
¹⁷ Arizona State University, Tempe, Arizona 85287, USA.
¹⁸ University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom.
¹⁹ University of Connecticut, Storrs, Connecticut 06269, USA.
²⁰ A. I. Alikhanyan National Science Laboratory (Yerevan Physics Institute), 0036, Yerevan, Armenia.
²¹ Stony Brook University, Stony Brook, New York 11794, USA.
²² Tomsk State University, 634050 Tomsk, Russia.
²³ Washington and Jefferson College, Washington, Pennsylvania 15301, USA.
²⁴ Osaka University, Osaka, Japan.
²⁵ The University of Tennessee, Knoxville, Tennessee 37996, USA.
²⁶ University of Regina, Regina, Saskatchewan S4S 0A2, Canada.
²⁷ GSI Helmholtz Centre for Heavy Ion Research, Darmstadt, Germany.
²⁸ Ruhr University Bochum, Bochum, Germany.
²⁹ University of Massachusetts Amherst, Amherst, Massachusetts 010031, USA.
³⁰ National Research Nuclear University MEPhI, Moscow 115409, Russia.
³¹ National Research Centre Kurchatov Institute, Moscow 123182, Russia.
³² University of North Texas, Denton, Texas 76201, USA.
³³ Wuhan University, Wuhan, Hubei, China.

PMID: 40479695
DOI: 10.1103/PhysRevLett.134.201903

Abstract

We report on the first measurement of J/ψ photoproduction from nuclei in the photon energy range of 7 to 10.8 GeV, extending above and below the photoproduction threshold in the free proton of ∼8.2 GeV. The experiment used a tagged photon beam incident on deuterium, helium, and carbon, and the GlueX detector at Jefferson Lab to measure the semi-inclusive A(γ,e^{+}e^{-}p) reaction with a dilepton invariant mass M(e^{+}e^{-})∼m_{J/ψ}=3.1 GeV. The incoherent J/ψ photoproduction cross sections in the measured nuclei are extracted as a function of the incident photon energy, momentum transfer, and proton-reconstructed missing light-cone momentum fraction. Comparisons with theoretical predictions assuming a dipole form factor allow for extracting a gluonic radius for bound protons of sqrt[⟨r^{2}⟩]=0.85±0.14 fm. The data also suggest an excess of the measured cross section for subthreshold production and for interactions with high missing light-cone momentum fraction protons. The measured enhancement can be explained by modified gluon structure for high-virtuality bound protons.

PubMed Disclaimer

LinkOut - more resources

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 Near-Threshold and Subthreshold J/ψ Photoproduction off Nuclei

Affiliations

First Measurement of Near-Threshold and Subthreshold J/ψ Photoproduction off Nuclei

Authors

Affiliations

Abstract

LinkOut - more resources

Miscellaneous