Measurement of the J/$\psi$ photoproduction cross section over the full near-threshold kinematic region

Abstract

We report the total and differential cross sections for $J/\psi$ photoproduction with the large acceptance GlueX spectrometer for photon beam energies from the threshold at 8.2~GeV up to 11.44~GeV and over the full kinematic range of momentum transfer squared, $t$. Such coverage facilitates the extrapolation of the differential cross sections to the forward ($t=0$) point beyond the physical region. The forward cross section is used by many theoretical models and plays an important role in understanding $J/\psi$ photoproduction and its relation to the $J/\psi -$proton interaction. These measurements of $J/\psi$ photoproduction near threshold are also crucial inputs to theoretical models that are used to study important aspects of the gluon structure of the proton, such as the gluon Generalized Parton Distribution (GPD) of the proton, the mass radius of the proton, and the trace anomaly contribution to the proton mass. We observe possible structures in the total cross section energy dependence and find evidence for contributions beyond gluon exchange in the differential cross section close to threshold, both of which are consistent with contributions from open-charm intermediate states.

15 pages 18 figures

References in corpus (17)

• Observation of a narrow pentaquark state, $P_c(4312{)}^{+}$, and of two-peak structure of the $P_c(4450{)}^{+}$
• The mass radius of the proton
• The GlueX Beamline and Detector
• QCD Analysis of Near-Threshold Photon-Proton Production of Heavy Quarkonium
• Studying the P_c(4450) resonance in J/psi photoproduction off protons
• Deciphering the mechanism of near-threshold $J/\psi$ photoproduction
• Nucleon mass radii and distribution: Holographic QCD, Lattice QCD and GlueX data
• Parameterization and applications of the low-$Q^2$ nucleon vector form factors
• Accessing the real part of the forward $J/\psi$-p scattering amplitude from $J/\psi$ photo-production on protons around threshold
• Near Threshold Heavy Quarkonium Photoproduction at Large Momentum Transfer
• Extraction of the proton mass radius from the vector meson photoproductions near thresholds
• J/$\psi$p Scattering Length from GlueX Threshold Measurements
• $\varphi$-meson lepto-production near threshold and the strangeness $D$-term
• $J/\psi$-$p$ Scattering Length from the Total and Differential Photoproduction Cross Sections
• The GlueX Start Counter Detector
• Mass structure of hadrons and light-front sum rules in t' Hooft model
• Electroproduction of heavy vector mesons using holographic QCD: from near threshold to high energy regimes

Cited by in corpus (21)

• Gravitational form factors of the proton from lattice QCD
• The Present and Future of QCD
• Pion gravitational form factors in the QCD instanton vacuum II
• Molecular $P_{\psi }$ pentaquarks from light-meson exchange saturation
• Interpretation of near-threshold peaks using the method of independent S-matrix poles
• Photo-production of ${\eta }_{c,b}$ near Threshold
• Prospects for detecting the hidden-strange pentaquarklike state $N^{\ast }(2080)$ in the ${\pi }^{-}p\to \varphi n$ reaction
• Momentum Flow Mechanisms and Color-Lorentz Forces on Quarks in the Nucleon
• Exclusive Charmonium Production at the Electron-ion collider in China
• First Measurement of Near- and Sub-Threshold $J/\psi$ Photoproduction off Nuclei
• "Rosenbluth" separation of the $J/\psi$ near-threshold photoproduction -- an access to the gluon Gravitational Form Factors at high $t$
• Deciphering the mechanism of $J/\psi$-nucleon scattering
• XYZ spectroscopy at electron-hadron facilities III: Semi-inclusive processes with vector exchanges
• Photoproduction of the $X(3872)$ beyond vector meson dominance: the open-charm coupled-channel mechanism
• Subthreshold production of $J/\psi$ mesons from the deuteron with SoLID
• Measurement of the near-threshold J$/\psi$ photoproduction cross section with the CLAS12 experiment
• Analysis of the hidden-charm pentaquark candidates in the $J/\psi p$ mass spectrum with QCD sum rules
• Gluon distributions and mass decompositions of the pion and kaon
• Target-Mass Corrections in the OPE Sum-Rule Approach to Quarkonium-Nucleon Interactions with Global-Fit PDFs: an $x$-Resolved Analysis
• Learning Pole Structures of Hadronic States using Predictive Uncertainty Estimation
• Near-Threshold OPE Constraints and High-Energy Diffractive Dynamics in J/psi Photoproduction