Inclusive quarkonium photoproduction selection and the effect of pileup at the LHC

Measurements of inclusive quarkonium photoproduction provide strong constraints on the quarkonium production mechanism; however, this process has not yet been measured at the LHC. We summarise our previously developed selection strategy for isolating inclusive quarkonium photoproduction in $p$Pb collisions at the LHC, which offer an optimal balance of photon flux, luminosity, and low pileup. We further examine the applicability of our selection criteria in different collision systems. While our method can be readily extended to PbPb collisions, $pp$ collisions require additional care due to the significantly higher pileup. We discuss how pileup affects the selection criteria, highlighting that it substantially degrades forward-detector–based selections and reduces the efficiency of rapidity-gap requirements.