Cuts for two-body decays at colliders

Autor: Gavin P. Salam, Emma Slade
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Journal of High Energy Physics, Vol 2021, Iss 11, Pp 1-61 (2021)
Journal of High Energy Physics
ISSN: 1029-8479
Popis: 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.
Comment: 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
Databáze: OpenAIRE
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