Tai-Fu Feng

Amplitude-level NLO predictions for exclusive $J/\psi+\gamma$ production in ultraperipheral collisions

Exclusive $\gamma\gamma\to J/\psi+\gamma$ production is studied in the color-singlet channel at leading order in the heavy-quark velocity. The conventional next-to-leading-order (NLO) result $B+V$, comprising Born production and its interference with the renormalized one-loop amplitude, is compared with $B+V+Q$, where...