Soft gluon resummation in the signal-background interference process of $gg(\to h^*) \to ZZ$

TL;DR

This paper provides a precise theoretical prediction for the gluon-gluon to ZZ process involving Higgs interference, incorporating soft gluon resummation and NNLO corrections to improve accuracy for Higgs property measurements.

Contribution

It introduces a comprehensive calculation including soft gluon resummation and approximate NNLO corrections for the $gg o h^* o ZZ$ process, enhancing the precision of Higgs interference predictions.

Findings

Approximate NNLO $K$-factor ranges from 2.05 to 2.45 at 8 TeV and 1.85 to 2.25 at 13 TeV.

Soft gluon resummation increases NNLO results by about 10%.

Theoretical uncertainties are around 10% at NNLL'.

Abstract

We present a precise theoretical prediction for the signal-background interference process of $gg(\to h^*) \to ZZ$, which is useful to constrain the Higgs boson decay width and to measure Higgs couplings to the SM particles. The approximate NNLO $K$-factor is in the range of $2.05-2.45$ ($1.85-2.25$), depending on $M_{ZZ}$, at the 8 (13) TeV LHC. And the soft gluon resummation can increase the approximate NNLO result by about $10\%$ at both the 8 TeV and 13 TeV LHC. The theoretical uncertainties including the scale, uncalculated multi-loop amplitudes of the background and PDF$+\alpha_s$ are roughly $\mathcal{O}(10\%)$ at ${\rm NNLL'}$. We also confirm that the approximate $K$-factors in the interference and the pure signal processes are the same.