{"@context":"http://schema.org","@id":"https://doi.org/10.17182/hepdata.110173.v1","@reverse":{"isBasedOn":[{"@type":"ScholarlyArticle","identifier":{"@type":"PropertyValue","propertyID":"URL","value":"https://inspirehep.net/literature/1736890"}},{"@id":"https://doi.org/10.1103/PhysRevLett.123.072001","@type":"JournalArticle"}]},"@type":"Dataset","additionalType":"Collection","author":{"@type":"Organization","name":"GlueX Collaboration"},"creator":{"@type":"Organization","name":"GlueX Collaboration"},"datePublished":"2021","description":"We report on the measurement of the $\\gamma p \\rightarrow J/\\psi p$ cross section from $E_\\gamma = 11.8$ GeV down to the threshold at $8.2$ GeV using a tagged photon beam with the GlueX experiment. We find the total cross section falls toward the threshold less steeply than expected from two-gluon exchange models. The differential cross section $d\\sigma /dt$ has an exponential slope of $1.67 \\pm 0.39$ GeV$^{-2}$ at $10.7$ GeV average energy. The LHCb pentaquark candidates $P_c^+$ can be produced in the $s$-channel of this reaction. We see no evidence for them and set model-dependent upper limits on their branching fractions $\\mathcal{B}(P_c^+ \\rightarrow J/\\psi p)$ and cross sections $\\sigma(\\gamma p \\to P_c^+)\\times\\mathcal{B}(P_c^+ \\to J/\\psi p) $.","hasPart":[{"@id":"https://doi.org/10.17182/hepdata.110173.v1/t1","@type":"Dataset","description":"$\\gamma p \\rightarrow J/\\psi p$ total cross-sections, statistical and systematic errors of the individual points in bins of beam energy....","name":"Total Cross Section"},{"@id":"https://doi.org/10.17182/hepdata.110173.v1/t2","@type":"Dataset","description":"$\\gamma p \\rightarrow J/\\psi p$ differential cross-sections, statistical and systematic errors of the individual points in bins of $-(t-t_{min})$. There...","name":"Differential Cross Section"}],"identifier":[{"@type":"PropertyValue","propertyID":"HEPDataRecord","value":"https://www.hepdata.net/record/ins1736890?version=1"},{"@type":"PropertyValue","propertyID":"HEPDataRecordAlt","value":"https://www.hepdata.net/record/110173"}],"inLanguage":"en","name":"First measurement of near-threshold J/$\\psi $ exclusive photoproduction off the proton","provider":{"@type":"Organization","name":"HEPData"},"publisher":{"@type":"Organization","name":"HEPData"},"url":"https://www.hepdata.net/record/ins1736890?version=1","version":1}