{"@context":"http://schema.org","@id":"https://doi.org/10.17182/hepdata.156183.v1","@reverse":{"isBasedOn":[{"@type":"ScholarlyArticle","identifier":{"@type":"PropertyValue","propertyID":"URL","value":"https://inspirehep.net/literature/2908607"}},{"@id":"https://doi.org/10.1103/2ssw-wwyy","@type":"JournalArticle"}]},"@type":"Dataset","additionalType":"Collection","author":{"@type":"Organization","name":"CMS Collaboration"},"creator":{"@type":"Organization","name":"CMS Collaboration"},"datePublished":"2025","description":"The first observation of coherent $\u03d5$(1020) meson photoproduction off heavy nuclei is presented using ultraperipheral lead-lead collisions at a center-of-mass energy per nucleon pair of 5.36 TeV. The data were collected by the CMS experiment and correspond to an integrated luminosity of 1.62 $\u03bc$b$^{-1}$. The $\u03d5$(1020) meson signals are reconstructed via the K$^+$K$^-$ decay channel. The production cross section is presented as a function of the $\u03d5$(1020) meson rapidity in the range 0.3 $\\lt$$\\lvert y\\rvert$$\\lt$ 1.0, probing gluons that carry a fraction of the nucleon momentum ($x$) around $10^{-4}$. The observed cross section exhibits little dependence on rapidity and is significantly suppressed, by a factor of ${\\sim}$5, compared to a baseline model that treats a nucleus as a collection of free nucleons. Theoretical models that incorporate the nuclear shadowing effect generally provide a better description of the $\u03d5$(1020) data than those incorporating gluon saturation. This study establishes a powerful new tool for exploring nuclear effects and nuclear gluonic structure in the small-$x$ regime at a unique energy scale bridging the perturbative and nonperturbative quantum chromodynamics domains.","hasPart":[{"@id":"https://doi.org/10.17182/hepdata.156183.v1/t1","@type":"Dataset","description":"The differential coherent $\\phi$ photoproduction cross section and the nuclear suppression factor as a function of rapidity.","name":"Table 1"}],"identifier":[{"@type":"PropertyValue","propertyID":"HEPDataRecord","value":"https://www.hepdata.net/record/ins2908607?version=1"},{"@type":"PropertyValue","propertyID":"HEPDataRecordAlt","value":"https://www.hepdata.net/record/156183"}],"inLanguage":"en","name":"Observation of coherent $\\phi$(1020) meson photoproduction in ultraperipheral PbPb collisions at $\\sqrt{s_\\text{NN}}$ = 5.36 TeV","provider":{"@type":"Organization","name":"HEPData"},"publisher":{"@type":"Organization","name":"HEPData"},"url":"https://www.hepdata.net/record/ins2908607?version=1","version":1}