Triple vector boson production through Higgs-Strahlung with NLO multijet merging

TL;DR

The paper develops and applies NLO QCD predictions for Higgsstrahlung-induced triple gauge boson production at the LHC, incorporating one-jet corrections via MEPS@NLO merging within a Sherpa/OpenLoops framework. It details S-MC@NLO, MENLOPS, and MEPS@NLO methods and their implementation for signal and dominant backgrounds, including WZ and WWW processes. Through CMS- and ATLAS-inspired trilepton analyses with Z- and jet-veto strategies, it demonstrates a measurable signal excess against backgrounds and shows perturbative uncertainties around the 10% level in key regions. This work underscores the value of combining fixed-order NLO accuracy with parton showers and multijet merging to enable precise Higgs-related measurements and new-physics searches at the LHC.

Abstract

Triple gauge boson hadroproduction, in particular the production of three $W$-bosons at the LHC, is considered at next-to leading order accuracy in QCD. The NLO matrix elements are combined with parton showers. Multijet merging is invoked such that NLO matrix elements with one additional jet are also included. The studies here incorporate both the signal and all relevant backgrounds for $VH$ production with the subsequent decay of the Higgs boson into $W$-- or $τ$--\-pairs. They have been performed using \SherpaOpenLoops in combination with Collier.

Figures (4)

• Figure 1: The trilepton invariant mass after CMS cuts. All contributing processes, grouped as whether considered signal or background, are added incoherently, ordered by relative contribution. The inset displays the same information on a logarithmic scale to better quantify the contributions of the rarer processes. Below the main plot the accumulated relative uncertainties originating from the respective signal and background processes to the total expected cross section are detailed.
• Figure 2: The missing transverse energy spectrum after CMS cuts. For details, see Fig. \ref{['fig:cms_mass']}.
• Figure 3: The missing transverse energy spectrum after ATLAS cuts. For details, see Fig. \ref{['fig:cms_mass']}.
• Figure 4: The angular separation of the closest pair of oppositely charged leptons in the case that no SFOS pair of leptons is found in the event after ATLAS cuts. For details, see Fig. \ref{['fig:cms_mass']}.