Cuts for two-body decays at colliders

Abstract

Fixed-order perturbative calculations of fiducial cross sections for two-body decay processes at colliders show disturbing sensitivity to unphysically low momentum scales and, in the case of $H\to \gamma \gamma$ in gluon fusion, poor convergence. Such problems have their origins in an interplay between the behaviour of standard experimental cuts at small transverse momenta ($p_t$) and logarithmic perturbative contributions. We illustrate how this interplay leads to a factorially divergent structure in the perturbative series that sets in already from the first orders. We propose simple modifications of fiducial cuts to eliminate their key incriminating characteristic, a linear dependence of the acceptance on the Higgs or $Z$-boson $p_t$, replacing it with quadratic dependence. This brings major improvements in the behaviour of the perturbative expansion. More elaborate cuts can achieve an acceptance that is independent of the Higgs $p_t$ at low $p_t$, with a variety of consequent advantages.

49 pages + appendices, 17 figures. Code that implements the cuts and Higgs defiducialisation at https://github.com/gavinsalam/two-body-cuts ; v2, as accepted by JHEP, adds two new appendices, on perturbative sensitivity to low scales and on defiducialisation, as well as various further clarifications and small fixes to some numerical values

References in corpus (7)

• An NNLO subtraction formalism in hadron collisions and its application to Higgs boson production at the LHC
• Higgs boson gluon-fusion production in N3LO QCD
• Higgs $p_T$ Spectrum and Total Cross Section with Fiducial Cuts at Third Resummed and Fixed Order in QCD
• Precise predictions for the angular coefficients in Z-boson production at the LHC
• Spin correlations in final-state parton showers and jet observables
• Angular distribution of leptons from the decay of massive vector bosons
• Matching N3LO QCD calculations to parton showers

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