{"@context":"http://schema.org","@id":"https://doi.org/10.17182/hepdata.138867.v2","@reverse":{"isBasedOn":[{"@type":"ScholarlyArticle","identifier":{"@type":"PropertyValue","propertyID":"URL","value":"https://inspirehep.net/literature/2648536"}},{"@id":"https://doi.org/10.1103/PhysRevLett.131.262301","@type":"JournalArticle"}]},"@type":"Dataset","additionalType":"Collection","author":{"@type":"Organization","name":"CMS Collaboration"},"creator":{"@type":"Organization","name":"CMS Collaboration"},"datePublished":"2024","description":"Quasireal photons exchanged in relativistic heavy ion interactions are powerful probes of the gluonic structure of nuclei. The coherent J/$\\psi$ photoproduction cross section in ultraperipheral lead-lead collisions is measured as a function of photon-nucleus center-of-mass energies per nucleon (W$^\\text{Pb}_{\\gamma\\text{N}}$), over a wide range of 40 $\\lt$ W$^\\text{Pb}_{\\gamma\\text{N}}$$\\lt$ 400 GeV. Results are obtained using data at the nucleon-nucleon center-of-mass energy of 5.02 TeV collected by the CMS experiment at the CERN LHC, corresponding to an integrated luminosity of 1.52 nb$^{-1}$. The cross section is observed to rise rapidly at low W$^\\text{Pb}_{\\gamma\\text{N}}$, and plateau above W$^\\text{Pb}_{\\gamma\\text{N}}$$\\approx$ 40 GeV, up to 400 GeV, a new regime of small Bjorken-$x$ ($\\approx$ 6 $\\times$ 10$^{-5}$) gluons being probed in a heavy nucleus. The observed energy dependence is not predicted by current quantum chromodynamic models.","hasPart":[{"@id":"https://doi.org/10.17182/hepdata.138867.v2/t1","@type":"Dataset","description":"The differential coherent $\\mathrm{J}/\\psi$ photoproduction cross section as a function of rapidity, in different neutron multiplicity classes: 0n0n, 0nXn, XnXn...","name":"Table 1"},{"@id":"https://doi.org/10.17182/hepdata.138867.v2/t2","@type":"Dataset","description":"The total coherent $\\mathrm{J}/\\psi$ photoproduction cross section as a function of photon-nuclear center-of-mass energy per nucleon $W_{\\gamma \\mathrm{N}}^{\\mathrm{Pb}}$, measured in...","name":"Table 2"},{"@id":"https://doi.org/10.17182/hepdata.138867.v2/t3","@type":"Dataset","description":"The nuclear gluon suppression factor $R_{\\mathrm{g}}^{\\mathrm{Pb}}$ as a function of Bjorken $x$ extracted from the CMS measurement of the coherent...","name":"Table 3"},{"@id":"https://doi.org/10.17182/hepdata.138867.v2/t4","@type":"Dataset","description":"The photon flux values from STARLight as a function of rapidity, in different neutron multiplicity classes: 0n0n, 0nXn, and XnXn.","name":"Table 4"},{"@id":"https://doi.org/10.17182/hepdata.138867.v2/t5","@type":"Dataset","description":"The covariance matrix for the flux in the 0n0n neutron multiplicity class.","name":"Flux Covariance Matrix 0n0n"},{"@id":"https://doi.org/10.17182/hepdata.138867.v2/t6","@type":"Dataset","description":"The covariance matrix for the flux in the 0nXn neutron multiplicity class.","name":"Flux Covariance Matrix 0nXn"},{"@id":"https://doi.org/10.17182/hepdata.138867.v2/t7","@type":"Dataset","description":"The covariance matrix for the flux in the XnXn neutron multiplicity class.","name":"Flux Covariance Matrix XnXn"},{"@id":"https://doi.org/10.17182/hepdata.138867.v2/t8","@type":"Dataset","description":"The total covariance matrix of the total coherent photoproduction cross section as a function of photon-nuclear center-of-mass energy per nucleon...","name":"Total covariance matrix"},{"@id":"https://doi.org/10.17182/hepdata.138867.v2/t9","@type":"Dataset","description":"The experimental covariance matrix of the total coherent photoproduction cross section as a function of photon-nuclear center-of-mass energy per nucleon...","name":"Experimental covariance matrix"},{"@id":"https://doi.org/10.17182/hepdata.138867.v2/t10","@type":"Dataset","description":"The theoretical (photon flux) covariance matrix of the total coherent photoproduction cross section as a function of photon-nuclear center-of-mass energy...","name":"Theoretical covariance matrix"}],"identifier":[{"@type":"PropertyValue","propertyID":"HEPDataRecord","value":"https://www.hepdata.net/record/ins2648536?version=2"},{"@type":"PropertyValue","propertyID":"HEPDataRecordAlt","value":"https://www.hepdata.net/record/138867"}],"inLanguage":"en","name":"Probing small Bjorken-$x$ nuclear gluonic structure via coherent J/$\\psi$ photoproduction in ultraperipheral PbPb collisions at $\\sqrt{s_\\mathrm{NN}}$ = 5.02 TeV","provider":{"@type":"Organization","name":"HEPData"},"publisher":{"@type":"Organization","name":"HEPData"},"url":"https://www.hepdata.net/record/ins2648536?version=2","version":2}