Associated production of a Higgs boson decaying into bottom quarks and a weak vector boson decaying leptonically at NNLO in QCD

Abstract

We present the calculation of next-to-next-to-leading order (NNLO) corrections in perturbative QCD for the production of a Higgs boson decaying into a pair of bottom quarks in association with a leptonically decaying weak vector boson: pp → V H+X → ¯ bb + X. We consider the corrections to both the production and decay sub-processes, retaining a fully differential description of the final state including off-shell propagators of the Higgs and vector boson. The calculation is carried out using the antenna subtraction formalism and is implemented in the NNLOJET framework. Clustering and identification of b-jets is performed with the flavour-k t algorithm and results for fiducial cross sections and distributions are presented for the LHC at √ s = 13 TeV. We assess the residual theory uncertainty by varying the production and decay scales independently and provide scale uncertainty bands in our results, yielding percent-level accurate predictions for observables in this Higgs production mode computed at NNLO. Confronting a naïve perturbative expansion of the cross section against the customary re-scaling procedure to a fixed branching ratio reveals that starting from NNLO, the latter could be inadequate in estimating missing higher-order effects through scale variations.arXiv:1907.05836v1 [hep-ph]

Higgs decay into massive b-quarks at NNLO QCD in the nested soft-collinear subtraction scheme

“…We note that the calculation presented in this paper is an important step towards a broader phenomenological goal, namely, combining a description of Higgs boson production with its decay into massive b-quarks. In the context of associated Higgs production, where large radiative corrections for important observables have been reported [17,18,21], a thorough study of b-quark mass effects is an interesting topic for future research.…”

“…Recently, a set of two-loop master integrals required for mixed QCD-electroweak corrections has been computed [14]. In the limit of massless b-quarks a number of fully differential next-to-next-to-leading order (NNLO) calculations of the H → bb decay have been presented [15][16][17][18] with first N 3 LO QCD results appearing recently [19]. The b-quark mass effects for differential observables have been studied at NNLO QCD in Ref.…”

“…[20], it is also an essential step towards studying mass effects in associated Higgs production with a vector boson, pp → HV → bbV . NNLO QCD corrections to this process have already been studied in the limit of massless b-quarks [17,18,21], and large effects, related to radiative corrections, have been reported. The impact of the b-quark mass may be sizeable in certain regions of the phase space.…”

LHC observables with NNLOJET

“…It is the aim of this report to present a computation of V H observables for all three processes (V = Z, W ± ) including NNLO corrections to both production and decay sub-processes retaining a fully differential description of the final state including offshell propagators of the Higgs and vector boson. Those results have been described in [4].…”

“…[6] (for V = W − ). Unlike the computation presented here and in [4], a scaling procedure to a fixed branching ratio is used in these aforementioned computations to define the cross section expressions at each perturbative order. By explicitly comparing the fiducial cross sections in these two frameworks, we argue furthermore in this work, that starting from NNLO the latter scaling procedure could be inadequate in estimating missing higher-order effects through scale variations.…”