Searching for a light Higgs boson via the Yukawa process at lepton colliders

Abstract

We explore the prospect of Yukawa production of a light boson which can exist in an extended Higgs sector. A particularly interesting case is the light pseudoscalar in Type-X two Higgs doublet model which can explain the anomalous magnetic moment of muon at large tan β. Considering ILC Higgs factory with √ s = 250 GeV, we show that the available parameter space can be fully examined by the (tau) Yukawa process at 5σ. We also demonstrate the mass reconstruction of such a light particle which helps to sizably minimize the background events.

Comparative studies of 2HDMs under the Higgs boson precision measurements

“…There have been many studies in the literature on the implications of the Higgs precision measurements at current and future colliders on the 2HDMs [39][40][41][42][43][44][45][46][47]. In recent works [48][49][50][51][52][53], we examined the achievable sensitivity of the Higgs and Z factories to probe the virtual effects of the two Higgs doublet model (2HDM) of Type-II and Type-I.…”

Explaining g − 2 anomalies in two Higgs doublet model with vector-like leptons

“…Hence a dedicated collider study is necessary to look for the VLL within 2HDM scenario and is beyond the scope of this paper. It is also remarkable that such a light pseudo-scalar can be readily probed by future linear colliders through the Yukawa process [72].…”

Leptophilic bosons and muon g-2 at lepton colliders

“…Limit from ILC is shown in red and black curves where solid and dashed line corresponds to exclusion(2σ) and discovery(5σ) limit at ILC250 with 2ab −1 of data. Limit of conventional analysis is taken from ref [46].…”

“…The purpose of this paper is to see how far in the lower mass range future collider experiments can reach and check whether the muon (g − 2) region of a scalar and pseudoscalar can be covered. At a lepton collider, a leptophilic boson can be produced via the Yukawa process [40][41][42][43][44][45][46] where a tau lepton radiates a boson, and then decays almost exclusively to a pair of leptons. If allowed kinematically, it leads to the conventional signal of four tau-lepton final states.…”

“…If allowed kinematically, it leads to the conventional signal of four tau-lepton final states. It is possible to probe the four-tau final state and use collinear approximation to reconstruct the mass at the ILC [46]. However, for a lighter boson, such a search method is not feasible as the decay products will be too collimated to be distinguished as two separate tau-tagged jets.…”