A comparative study of Higgs boson production from vector-boson fusion

Abstract

The data taken in Run II at the Large Hadron Collider have started to probe Higgs boson production at high transverse momentum. Future data will provide a large sample of events with boosted Higgs boson topologies, allowing for a detailed understanding of electroweak Higgs boson plus two-jet production, and in particular the vector-boson fusion mode (VBF). We perform a detailed comparison of precision calculations for Higgs boson production in this channel, with particular emphasis on large Higgs boson transverse momenta, and on the jet radius dependence of the cross section. We study fixed-order predictions at next-to-leading order and next-to-next-to-leading order QCD, and compare the results to NLO plus parton shower (NLOPS) matched calculations. The impact of the NNLO corrections on the central predictions is mild, with inclusive scale uncertainties of the order of a few percent, which can increase with the imposition of kinematic cuts. We find good agreement between the fixed-order and matched calculations in non-Sudakov regions, and the various NLOPS predictions also agree well in the Sudakov regime. We analyze backgrounds to VBF Higgs boson production stemming from associated production, and from gluon-gluon fusion. At high Higgs boson transverse momenta, the ∆yjj and/or mjj cuts typically used to enhance the VBF signal over background lead to a reduced efficiency. We examine this effect as a function of the jet radius and using different definitions of the tagging jets. QCD radiative corrections increase for all Higgs production modes with increasing Higgs boson pT, but the proportionately larger increase in the gluon fusion channel results in a decrease of the gluon-gluon fusion background to electroweak Higgs plus two jet production upon requiring exclusive two-jet topologies. We study this effect in detail and contrast in particular a central jet veto with a global jet multiplicity requirement.

Event Generators for High-Energy Physics Experiments

“…Moreover, the presence of small but non-vanishing masses also presents numerical challenges in evaluating higher-order corrections. These issues, together with tools for the computation of hard processes at lepton Higgs H [67,68,80,81] [70, 76, 82, 83] W ± H [84][85][86] ZH [86,87] H (VBF) [72,88] HH [89] HHH [90] H+jet [91][92][93][94][95][96][97][98] W ± H+jet [99] ZH+jet [100] SM candles W ± [70,74,101,102] Z [68,70,74,102,103] γγ [74,[104][105][106][107] W ± γ [74,[108][109][110] Zγ [74,111,111] W + W − [74,[112][113][114]…”

A Study of QCD Radiation in VBF Higgs Production with Vincia and Pythia

“…We consider only VBF topologies, neglecting Higgsstrahlung contributions which appear at the same order in the strong and electroweak coupling. Identical-flavour interference effects are neglected in events generated with POWHEG-BOX and PYTHIA, but are included in events obtained with SHERPA, although their impact was found to be small [9]. At NLO, the process is calculated in the structure function approximation, neglecting interferences between the two quark lines.…”

“…For more exclusive event properties, such as bremsstrahlung and hadronisation corrections, the most detailed description is offered by combinations of fixed-order and parton-shower calculations. To this end, two recent phenomelogical studies [8,9] compared different NLO+PS simulations among each other as well as to NLO and NNLO calculations. These comparative studies catered to two needs; firstly, the reliability of matched calculations was tested in regions where resummation effects are small.…”

“…The more recent study [9] highlighted a number of interesting aspects of vector boson fusion that can be exploited to enhance the signal-to-background ratio in future measurements: Firstly, if the Higgs boson is boosted, the t-channel structure of the VBF matrix elements leads to less QCD radiation when compared to the irreducible background from gluon-gluon fusion. Secondly, it was found that a global jet veto provides a similarly effective cut as a central jet veto, leading to much reduced theoretical uncertainties, and in particular eliminating the need to resum non-global logarithms associated with inhibited radiation in the rapidity gap.…”

NNLO QCD corrections to weak boson fusion Higgs boson production in the H → b$$ \overline{b} $$ and H → WW* → 4l decay channels

“…2 This statement does not hold for interference contributions to the qq → Hqq amplitude squared. However, these contributions are known to be tiny when WBF cuts are applied [10,12,13]. 3 A recent summary on progress in this direction was given in ref.…”