Phenomenology of combined resummation for Higgs and Drell-Yan

Abstract We study the phenomenological impact of a recently suggested formalism for the combination of threshold and a so-called threshold-improved transverse momentum resummation, by using it to improve the fixed-order results. This formalism allows for a systematic improvement of the transverse momentum resummation that is valid in the entire range of pT by the inclusion of the threshold contribution. We use the Borel method as a suitable prescription for defining the inverse Mellin and Fourier transforms in the context of combined resummed expression. The study is applied to two QCD processes, namely the Higgs boson produced via gluon fusion and Z boson production via the Drell-Yan mechanism. We compare our results to the standard transverse momentum resummation, as well as to the fixed-order results. We find that the threshold-improved transverse momentum resummation leads to faster perturbative convergence at small pT while the inclusion of threshold resummation improves the agreement with fixed-order calculations at medium and large pT. These effects are more pronounced in the case of Higgs which is known to have slower perturbative convergence.

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Higher-order power corrections in a transverse-momentum cut for colour-singlet production at NLO

The European Physical Journal C ◽

10.1140/epjc/s10052-019-7361-8 ◽

2019 ◽

Vol 79 (10) ◽

Cited By ~ 4

Author(s):

Leandro Cieri ◽

Carlo Oleari ◽

Marco Rocco

Keyword(s):

Higgs Boson ◽

Transverse Momentum ◽

Cross Section ◽

Gluon Fusion ◽

Fourth Power ◽

Power Correction ◽

Boson Production ◽

Higgs Boson Production ◽

Power Corrections ◽

The Impact

Abstract We consider the production of a colourless system at next-to-leading order in the strong coupling constant $$\alpha _{{\displaystyle } {\scriptstyle } {\scriptscriptstyle } {\scriptscriptstyle } \mathrm{S}}$$αS. We impose a transverse-momentum cutoff, $$q_{{\displaystyle } {\scriptstyle } {\scriptscriptstyle } {\scriptscriptstyle } \mathrm{T}}^{{\displaystyle } {\scriptstyle } {\scriptscriptstyle } {\scriptscriptstyle } \mathrm{cut}}$$qTcut, on the colourless final state and we compute the power corrections for the inclusive cross section in the cutoff, up to the fourth power. The study of the dependence of the cross section on $$q_{{\displaystyle } {\scriptstyle } {\scriptscriptstyle } {\scriptscriptstyle } \mathrm{T}}^{{\displaystyle } {\scriptstyle } {\scriptscriptstyle } {\scriptscriptstyle } \mathrm{cut}}$$qTcut allows for an understanding of its behaviour at the boundaries of the phase space, giving hints on the structure at all orders in $$\alpha _{{\displaystyle } {\scriptstyle } {\scriptscriptstyle } {\scriptscriptstyle } \mathrm{S}}$$αS and on the identification of universal patterns. The knowledge of such power corrections is also a required ingredient in order to reduce the dependence on the transverse-momentum cutoff of the QCD cross sections at higher orders, when the $$q_{\mathrm{T}}$$qT-subtraction method is applied. We present analytic results for both Drell–Yan vector boson and Higgs boson production in gluon fusion and we illustrate a process-independent procedure for the calculation of the all-order power corrections in the cutoff. In order to show the impact of the power-correction terms, we present selected numerical results and discuss how the residual dependence on $$q_{{\displaystyle } {\scriptstyle } {\scriptscriptstyle } {\scriptscriptstyle } \mathrm{T}}^{{\displaystyle } {\scriptstyle } {\scriptscriptstyle } {\scriptscriptstyle } \mathrm{cut}}$$qTcut affects the total cross section for Drell–Yan Z production and Higgs boson production via gluon fusion at the LHC.

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

Journal of High Energy Physics ◽

10.1007/jhep11(2021)108 ◽

2021 ◽

Vol 2021 (11) ◽

Author(s):

A. Buckley ◽

X. Chen ◽

J. Cruz-Martinez ◽

S. Ferrario Ravasio ◽

T. Gehrmann ◽

...

Keyword(s):

Higgs Boson ◽

Vector Boson ◽

Gluon Fusion ◽

Boson Production ◽

Vector Boson Fusion ◽

Leading Order ◽

Jet Production ◽

Higgs Boson Production ◽

Fixed Order ◽

The Impact

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.

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