Next-to-next-to-leading order event generation for $VH$ production with $H\to b\bar{b}$ decay

TL;DR

This paper presents advanced NNLO event generators for Higgsstrahlung processes with $H\to b\bar{b}$ decay, achieving high precision in production and decay simulations, validated against experimental data.

Contribution

It introduces the first NNLO+PS accurate simulations for $W^{\pm}H$ production including decay, using the MiNNLO$_{\rm PS}$ method, improving upon previous NNLOPS approaches.

Findings

Predictions agree well with recent experimental measurements.

First NNLO+PS accuracy achieved for $W^{\pm}H$ production with decay.

New generators evaluate NNLO corrections dynamically during event generation.

Abstract

We consider the Higgsstrahlung process in hadronic collisions and present the computation of next-to-next-to-leading order predictions matched to parton showers for both production and $H\to b\bar{b}$ decay employing the MiNNLO$_{\rm PS}$ method. We present predictions for $ZH$ and $W^{\pm}H$ production including spin correlations and off-shell effects by calculating the full processes $pp \to \ell^+\ell^-H \to \ell^+\ell^-b\bar{b}$, $pp \to \nu_\ell\bar\nu_\ell H \to \nu_\ell\bar\nu_\ell b\bar{b}$ and $pp \to \ell^\pm \nu_\ell H \to \ell^\pm \nu_\ell b\bar{b}$ in the narrow-width approximation for the Higgs boson. For the $W^{\pm}H$ process, NNLO+PS accuracy in production and decay is achieved for the first time. Our calculations are validated against earlier simulations in the NNLOPS approach that includes NNLO corrections via multi-differential reweighting. The new MiNNLO$_{\rm PS}$ generators for these processes, which evaluate NNLO corrections on-the-fly in the event generation, will supersede those earlier calculations. Our predictions are in good agreement with recent measurements of the Higgsstrahlung cross sections.