Pseudoscalar heavy quarkonium production in heavy ion ultraperipheral collision

Abstract

The inclusive production of pseudoscalar heavy quarkoniua ($\eta_c,~\eta_b$ and $B_c$) via photon-photon fusion in heavy ion ultraperipheral collision (UPC) are calculated to QCD next-to-leading order in the framework of non-relativistic QCD (NRQCD). The total cross section of $\eta_c$ produced in Pb-Pb UPC is 194 $\mathrm{nb}$ and 1275 $\mathrm{nb}$ at nucleon-nucleon c.m. energies $\sqrt{S_{\mathrm{NN}}}=$ 5.52 TeV and 39.4 TeV, respectively. The cross sections for $\eta_b$ and $B_c$ mesons are more than two to three orders of magnitude smaller. We make a detailed phenomenological analysis on the $\eta_c$ production; the uncertainties caused by the renormalization scale and the charm quark mass, the cross sections in other ultraperipheral nucleon-nucleon colliding systems, and the transverse momentum distribution are discussed. At the coming HL-LHC and future FCC, the heavy ion UPC opens another door of the study on the production of heavy quarkonium.