Exotic Decays of the 125 GeV Higgs Boson

Abstract

We perform an extensive survey of non-standard Higgs decays that are consistent with the 125 GeV Higgs-like resonance. Our aim is to motivate a large set of new experimental analyses on the existing and forthcoming data from the Large Hadron Collider (LHC). The explicit search for exotic Higgs decays presents a largely untapped discovery opportunity for the LHC collaborations, as such decays may be easily missed by other searches. We emphasize that the Higgs is uniquely sensitive to the potential existence of new weakly coupled particles and provide a unified discussion of a large class of both simplified and complete models that give rise to characteristic patterns of exotic Higgs decays. We assess the status of exotic Higgs decays after LHC Run I. In many cases we are able to set new nontrivial constraints by reinterpreting existing experimental analyses. We point out that improvements are possible with dedicated analyses and perform some preliminary collider studies. We prioritize the analyses according to their theoretical motivation and their experimental feasibility. This document is accompanied by a website that will be continuously updated with further information: exotichiggs.physics.sunysb.edu.

Exotic Higgs Decays

“…Note that at dimension five there are no a couplings to the Higgs doublet. 4 After electroweak symmetry breaking, these two operators will lead to the decays h → aa [56,57] and h → aZ [58], respectively. The corresponding widths are given by…”

“…where we have defined η ≡ /(cos θ 1 − 2 / cos 2 θ). The kinetic mixing also leads to the decay h → Z D Z D , but the width of this decay is suppressed by 4 , making it highly sub-leading. However, if the Z D mass is generated by a dark Higgs mechanism, the dark scalar-Higgs mixing induced by the Lagrangian in Equation 3.1 also contributes to the decay…”

“…Exotic Higgs decays have long been appreciated as potential signals of new physics, beginning with the pioneering work of Suzuki and Shrock [3]. A large body of work on exotic Higgs decays has been motivated by solutions to the hierarchy problem, particularly in the context of extended SUSY models (though see also composite Higgs models) as well as Higgs portal dark matter (see the paper [4] for details about both models and signatures). In this review article, we focus on theoretical motivations for exotic Higgs decays that have been substantially developed since [4] and the major advances in the experimental search for these signatures.…”

Beyond Standard Model Higgs boson physics with the ATLAS experiment at the LHC

“…Enhancement of rare decays, completely new decays and production mechanisms, and different couplings with respect to the SM expectations are possible and may indicate connections to other puzzles, such as dark matter (e.g., see Ref. [20] and references therein).…”

Don't Miss the Displaced Higgs at the LHC Again

“…Ref. [5]). In this letter, we will show that the experimental triggers currently in use at CMS and ATLAS are poorly suited to discover extensions of the Higgs sector involving long-lived particles.…”