HW/HZ + 0 and 1 jet at NLO with the POWHEG BOX interfaced to GoSam and their merging within MiNLO

TL;DR

This paper introduces an automated NLO generator for Higgs and vector boson production with zero and one jet, interfaced with GoSam and MiNLO, enhancing precision and automation in particle physics simulations.

Contribution

It develops a fully automated POWHEG generator for HV + 1 jet production using GoSam and MiNLO, improving accuracy and integration in theoretical calculations.

Findings

Automated virtual correction computation with GoSam.

NLO accuracy achieved for both inclusive and exclusive distributions.

Successful application of MiNLO in HV production context.

Abstract

We present a generator for the production of a Higgs boson H in association with a vector boson V=W or Z (including subsequent V decay) plus zero and one jet, that can be used in conjunction with general-purpose shower Monte Carlo generators, according to the POWHEG method, as implemented within the POWHEG BOX framework. We have computed the virtual corrections using GoSam, a program for the automatic construction of virtual amplitudes. In order to do so, we have built a general interface of the POWHEG BOX to the GoSam package. With this addition, the construction of a POWHEG generator within the POWHEG BOX is now fully automatized, except for the construction of the Born phase space. Our HV + 1 jet generators can be run with the recently proposed MiNLO method for the choice of scales and the inclusion of Sudakov form factors. Since the HV production is very similar to V production, we were able to apply an improved MiNLO procedure, that was recently used in H and V production, also in the present case. This procedure is such that the resulting generator achieves NLO accuracy not only for inclusive distributions in HV + 1 jet production but also in HV production, i.e. when the associated jet is not resolved, yielding a further example of matched calculation with no matching scale.