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Article
Report number	arXiv:2307.09992 ; MPP-2023-103 ; PSI-PR-23-26 ; TIF-UNIMI-2023-16
Title	Taming a leading theoretical uncertainty in HH measurements via accurate simulations for $ \textrm{b}\overline{\textrm{b}}\textrm{H} $ production
Author(s)	Manzoni, Stefano (CERN) ; Mazzeo, Elena (Milan U.) ; Mazzitelli, Javier (PSI, Villigen) ; Wiesemann, Marius (Munich, Max Planck Inst.) ; Zaro, Marco (Milan U.)
Publication	2023-09-26
Imprint	2023-07-19
Number of pages	26
In:	JHEP 2309 (2023) 179
DOI	10.1007/JHEP09(2023)179
Subject category	hep-ex ; Particle Physics - Experiment ; hep-ph ; Particle Physics - Phenomenology
Abstract	We present a new simulation for Higgs boson production in association with bottom quarks ($b\bar{b}H$) at next-to-leading order (NLO) accuracy matched to parton showers in hadronic collisions. Both contributions, the standard one proportional to the bottom-quark Yukawa coupling and the loop-induced one proportional to the top-quark Yukawa coupling from the gluon-fusion process, are taken into account in a scheme with massive bottom quarks. Therefore, we provide the full simulation of the $b\bar{b}H$ final state in the Standard Model, which constitutes also a crucial background to measurements for Higgs-boson pair ($HH$) production at the Large Hadron Collider when at least one of the Higgs bosons decays to bottom quarks. So far, the modeling of the $b\bar{b}H$ final state induced one of the dominant theoretical uncertainties to $HH$ measurements, as the gluon-fusion component was described only at the leading order (LO) with uncertainties of $\mathcal{O}(100\%)$. Including NLO corrections in its simulation allows us to reduce the scale dependence to $\mathcal{O}(50\%)$ so that it becomes subdominant with respect to other systematic uncertainties. As a case study, we provide an in-depth analysis of the $b\bar{b}H$ background to $HH$ measurements with realistic selection cuts in the $2b2\gamma$ channel. We also compare our novel simulation with the currently-employed ones, discussing possible issues and shortcomings of a scheme with massless bottom quarks. Finally, we propagate the effect of the new $b\bar{b}H$ simulation to $HH$ searches in the $2b2\gamma$ and $2b2\tau$ final states, and we find an improvement of up to 10% (20%) on the current (HL-LHC) limits on the $HH$ cross section.
Copyright/License	preprint: (License: arXiv nonexclusive-distrib 1.0) publication: © 2023-2025 The Authors (License: CC-BY-4.0), sponsored by SCOAP³

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