Doubly charged Higgs at LHC

Abstract

We have investigated production of doubly charged Higgs particles $\Delta_{L,R}^{++}$ via WW fusion process in proton-proton collisions at LHC energies in the framework of the left-right symmetric model. The production cross section of the right-triplet Higgs is for representative values of model parameters at femtobarn level. The discovery reach depends on the mass of the right-handed gauge boson W_R. At best $\Delta_R^{++}$ mass up to 2.4 TeV are achievable within one year run. For $\Delta^{++}_L$ the corresponding limit is 1.75 TeV which depends on the value of the left-triplet vev v_L. Comparison with Drell-Yan pair production processes shows that studies of the WW fusion processes extend the discovery reach of LHC roughly by a factor of two. The main experimental signal of a produced Higgs would be a hard same-sign lepton pair. There will be no substantial background due to the Standard Model (SM) interactions, since in the SM a same-sign lepton pair will always be associated with missing energy, i.e. neutrinos, due to lepton number conservation.Comment: Revised version, some results changed, to appear in NP

Electroweak phase transition in left-right symmetric models

“…1 we plot the ratio k(T c )/T c against the lightest scalar mass m 1 , corresponding to a sample of 500 points in the parameter space which passed our selection criterion. As we see, there is a sizeable fraction which satisfies the condition for preserving the baryon asymmetry, k(T c )/T c > 1, and corresponds to experimentally allowed values of the lightest scalar mass, m 1 > 50 GeV [29]. We find this result to be particularly interesting, given the relatively large number of potential signatures of such a model in future experiments [22] and the small number of free parameters to adjust the remaining phenomenology [30].…”

Doubly charged scalar decays in a type II seesaw scenario with two Higgs triplets

“…On the other hand, in the scenario with two scalar triplets with charged mass eigenstates H ++ k and H + l (k, l = 1, 2), the decay amplitude for H ++ 1 → H + 2 W + , if kinematically allowed, is controlled by the SU(2) gauge coupling. Therefore, if one identifies regions of the parameter space where it dominates, one needs to devise new search strategies at the LHC [36][37][38][39][40][41][42][43][44], including ways of eliminating backgrounds.…”

Search for neutral and charged BSM Higgs Bosons with the ATLAS detector

“…In all cases, branching to final states other than a lepton pair was assumed to be negligible. The left panel of Figure 11 gives the 95% CL limit on H ±± L mass as a function of branching ratio Br(H ±± L → l ± l ± ), where l stands for either e or µ. H ±± L in the LRSM is the H ±± state coupling to the left-handed fermions and has a few times larger predicted production cross-section than its right-handed counterpart (H ±± R ) [31].…”