## Coherent photoproduction of $\rho^{0}$ vector mesons in ultra-peripheral Pb-Pb collisions at $\sqrt{{\mathrm{s}}_{\mathrm{NN}}}$ = 5.02 TeV

### Abstract

International audienceCross sections for the coherent photoproduction of ρ$^{0}$ vector mesons in ultra-peripheral Pb-Pb collisions at $\sqrt{{\mathrm{s}}_{\mathrm{NN}}}$ = 5.02 TeV are reported. The measurements, which rely on the π$^{+}$π$^{−}$ decay channel, are presented in three regions of rapidity covering the range |y| < 0.8. For each rapidity interval, cross sections are shown for different nuclear-breakup classes defined according to the presence of neutrons measured in the zero-degree calorimeters. The results are compared with predictions based on different models of nuclear shadowing. Finally, the observation of a coherently produced resonance-like structure with a mass around 1.7 GeV/c$^{2}$ and a width of about 140 MeV/c$^{2}$ is reported and compared with similar observations from other experiments.[graphic not available: see fulltext

Topics: Heavy Ion Experiments, Heavy-ion collision, Particle and resonance production, rho(770)0: photoproduction, heavy ion: scattering, nucleus: shadowing, calorimeter: forward spectrometer, vector meson, coherence, rapidity, experimental results, 5020 GeV-cms/nucleon, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]
Publisher: 'Springer Science and Business Media LLC'
Year: 2020
DOI identifier: 10.1007/JHEP06(2020)035
OAI identifier: oai:HAL:hal-02504650v1