Exclusive $J/\psi+\gamma$ production in ultraperipheral ion collisions

TL;DR

This paper calculates the cross section for exclusive $J/c+b$ production in ultraperipheral ion collisions at the LHC, including higher-order corrections, and finds these effects significantly reduce the leading-order prediction, aiding future experimental studies.

Contribution

It provides the first detailed calculation of $c+b$ production in UPCs at $c$-colliders, incorporating $c(c ext{ corrections and relativistic effects within NRQCD.

Findings

Higher-order corrections reduce the LO cross section by about 66%.

The corrections show good convergence in $c_s$ and $v^2$ expansions.

Results indicate future measurements are feasible and important for understanding quarkonium production.

Abstract

Ultraperipheral collisions (UPCs) of ions provide new opportunities to study the quarkonium production mechanism in photon-photon scattering. In this paper, we investigate the exclusive process $\gamma+\gamma\to J/\psi+\gamma$ up to $\mathcal{O}(\alpha_s v^2)$ accuracy within the nonrelativistic quantum chromodynamics factorization framework. We evaluate the corresponding cross sections for Pb-Pb and p-p UPCs at the Large Hadron Collider. Numerical results show that the $\mathcal{O}(\alpha_s)$, $\mathcal{O}(v^2)$, and $\mathcal{O}(\alpha_s v^2)$ corrections are about $-50\%$, $-33\%$, and $15\%$ of the leading-order (LO) contribution, respectively, showing reasonable convergence in both $\alpha_s$ and $v^2$ expansion. Collectively, these corrections suppress the LO cross section by a factor of about $1/3$, which is a crucial effect for reliable phenomenological analysis. Our results suggest that future experimental measurements of this process are feasible.