Toponium hadroproduction at next-to-next-to-leading order in NRQCD

Abstract

We present the first next-to-next-to-leading-order (NNLO) predictions for inclusive color-singlet toponium hadroproduction within NRQCD in the zero-width limit for the top quark. The central new result is the NNLO QCD correction to the short-distance coefficient for pseudoscalar toponium production. The predictions include electroweak and relativistic corrections, additional production channels, and perturbatively evaluated bound-state matrix elements. At the Large Hadron Collider proton-proton center-of-mass energy of $13\,\mathrm{TeV}$, we obtain a cross section of $4.87^{+0.63}_{-0.65}\,\mathrm{pb}$, with scale and parametric uncertainties combined. The NNLO corrections reduce the renormalization- and factorization-scale uncertainties by approximately a factor of four relative to NLO, to the few-percent level. The dominant remaining uncertainty arises from the Coulomb-scale dependence of the bound-state matrix elements.