The Higgs boson at high $p_T$

TL;DR

This paper calculates the Higgs boson production with a jet at high transverse momentum, including finite top-mass effects at NLO, and demonstrates the convergence and accuracy of the asymptotic expansion for modeling top-mass effects up to 300 GeV.

Contribution

It provides the first convergent calculation of high-$p_T$ Higgs production including finite top-mass effects at NLO, improving modeling accuracy in this energy regime.

Findings

Convergent behavior for $p_T^H > m_t$ with asymptotic expansion.

Rescaling by $m_t$-exact LO cross section effectively models top-mass effects.

Error from LO rescaling comparable to NNLO scale uncertainty at high energies.

Abstract

We present a calculation of $H+j$ at NLO including the effect of a finite top-mass. Where possible we include the complete dependence on $m_t$. This includes the leading order amplitude, the infrared poles of the two-loop amplitude and the real radiation amplitude. The remaining finite piece of the virtual correction is considered in an asymptotic expansion in $m_t$, which is accurate to $m_t^{-4}$. By successively including more $m_t$-exact pieces, the dependence on the asymptotic series diminishes and we find convergent behavior for $p_T^H>m_t$ for the first time. Our results justify rescaling by the $m_t$-exact LO cross section to model top-mass effects in EFT results up to $p_T$ of 250 to 300 GeV. We show that the error made by using the LO rescaling becomes comparable to the NNLO scale uncertainty for such large energies. We implement our results into the Monte Carlo code MCFM.