Revisiting the non-resonant Higgs pair production at the HL-LHC

Adhikary, Amit and Banerjee, Shankha and Barman, Rahool Kumar and Bhattacherjee, Biplob and Niyogi, Saurabh (2018) Revisiting the non-resonant Higgs pair production at the HL-LHC. In: JOURNAL OF HIGH ENERGY PHYSICS (7).

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Abstract

We study the prospects of observing the non-resonant di-Higgs pair production in the Standard Model (SM) at the high luminosity run of the 14TeV LHC (HL-LHC), upon combining multiple final states chosen on the basis of their yield and cleanliness. In particular, we consider the b (b) over bar gamma gamma; b (b) over bar (tau+tau-), b (b) over bar WW*;WW*gamma gamma and 4W channels mostly focusing on final states with photons and/or leptons and study 11 final states. We employ multivariate analyses to optimise the discrimination between signal and backgrounds and find it performing better than simple cut-based analyses. The various differential distributions for the Higgs pair production have non-trivial dependencies on the Higgs self-coupling (lambda(hhh)). We thus explore the implications of varying lambda(hhh) for the most sensitive search channel for the double Higgs production, viz., b (b) over bar gamma gamma gamma. The number of signal events originating from SM di-Higgs production in each final state is small and for this reason measurement of differential distributions may not be possible. In order to extract the Higgs quartic coupling, we have to rely on the total number of events in each final state and these channels can be contaminated by various new physics scenarios. Furthermore, we consider various physics beyond the standard model scenarios to quantify the effects of contamination while trying to measure the SM di-Higgs signals in detail. In particular, we study generic resonant heavy Higgs decays to a pair of SM-like Higgs bosons or to a pair of top quarks, heavy pseudoscalar decaying to an SM-like Higgs and a Z-boson, charged Higgs production in association with a top and a bottom quark and also various well-motivated supersymmetric channels. We set limits on the cross-sections for the aforementioned new physics scenarios, above which these can be seen as excesses over the SM background and affect the measurement of Higgs quartic coupling. We also discuss the correlations among various channels which can be useful to identify the new physics model.

Item Type:	Journal Article
Publication:	JOURNAL OF HIGH ENERGY PHYSICS
Publisher:	SPRINGER, 233 SPRING ST, NEW YORK, NY 10013 USA
Additional Information:	Copyright of this article belong to SPRINGER, 233 SPRING ST, NEW YORK, NY 10013 USA
Department/Centre:	Division of Physical & Mathematical Sciences > Centre for High Energy Physics
Date Deposited:	09 Aug 2018 15:40
Last Modified:	09 Aug 2018 15:40
URI:	http://eprints.iisc.ac.in/id/eprint/60386

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