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| Publications [#383431] of Haiyan Gao
Papers Published
- Pybus, JR; Ehinger, L; Kolar, T; Devkota, B; Sharp, P; Yu, B; Dalton, MM; Dutta, D; Gao, H; Hen, O; Piasetzky, E; Santiesteban, SN; Schmidt, A; Somov, A; Szumila-Vance, H; Adhikari, S; Asaturyan, A; Austregesilo, A; Ayerbe Gayoso, C; Barlow, J; Berdnikov, VV; Bhatt, HD; Bhetuwal, D; Black, T; Briscoe, WJ; Chung, G; Cole, PL; Deur, A; Dotel, R; Egiyan, H; Eugenio, P; Fanelli, C; Gan, L; Gasparian, A; Guo, J; Hernandez, K; Higinbotham, DW; Hurck, P; Jaegle, I; Jones, RT; Kakoyan, V; Karki, A; Li, H; Li, WB; Linera, GR; Lyubovitskij, V; Marukyan, H; McCaughan, MD; McCracken, M; Mizutani, K; Nguyen, D; Oresic, S; Ostrovidov, AI; Papandreou, Z; Paudel, C; Peters, K; Ritman, J; Schick, A; Schwiening, J; Smith, A; Somov, S; Strakovsky, I; Suresh, K; Tarasov, VV; Taylor, S; Xiao, T; Zhang, Z; Zhou, X, First Measurement of Near-Threshold and Subthreshold J/ψ Photoproduction off Nuclei.,
Physical review letters, vol. 134 no. 20
(May, 2025),
pp. 201903 [doi]
(last updated on 2026/01/15)
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.
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