Explaining dark matter and neutrino mass in the light of TYPE-II seesaw model

Abstract

With the motivation of simultaneously explaining dark matter and neutrino masses, mixing angles, we have invoked the Type-II seesaw model extended by an extra SU (2) doublet Φ. Moreover, we have imposed a Z 2 parity on Φ which remains unbroken as the vacuum expectation value of Φ is zero. Consequently, the lightest neutral component of Φ becomes naturally stable and can be a viable dark matter candidate. On the other hand, light Majorana masses for neutrinos have been generated following usual Type-II seesaw mechanism. Further in this framework, for the first time we have derived the full set of vacuum stability and unitarity conditions, which must be satisfied to obtain a stable vacuum as well as to preserve the unitarity of the model respectively. Thereafter, we have performed extensive phenomenological studies of both dark matter and neutrino sectors considering all possible theoretical and current experimental constraints. Finally, we have also discussed a qualitative collider signatures of dark matter and associated odd particles at the 13 TeV Large Hadron Collider.

Reconciling dark matter, $$ {R}_{K^{\left(\ast \right)}} $$ anomalies and (g − 2)μ in an Lμ − Lτ scenario

“…strongly correlated with the physics of rare B-decays and anomalous magnetic moment of µ, where the role of new gauge boson Z µτ is extremely crucial. Moreover, it also helps us to evade the strong bound coming from the experiments of direct detection [109], indirect detection [145] and also from the collider on Higgs invisible branching [110] for the low mass scalar dark matter [146][147][148], where bb final state is the principal annihilation channel. Therefore, in spite of being a gauge singlet Z 2 -odd scalar field, the mixing with another Z 2 -odd field (part of an SU(2) L doublet) having nonzero L µ − L τ charge, makes the entire dynamics of our dark matter candidate ρ 1 strikingly different from the standard Scalar Singlet dark matter scenario [105][106][107][108].…”

“…is clearly visible in the right panel of figure 10, where we have shown the allowed range of θ D with respect to M ρ 1 . However, in the high mass regime (M ρ 1 ≥ 500 GeV), large values of θ D 0.3 rad are still allowed because for such large θ D , ρ 1 is mostly an SU(2) L doublet like state (similar to the Inert Doublet dark matter in high mass range [148][149][150]) which attains the present abundance of dark matter through co-annihilations with other Z 2 -odd fields into various bosonic final states (both vector and scalar). Moreover, we have also seen from the figure 9 that the magnitude of ∆C 9 (eq.…”

Reconciling dark matter, $R_{K^{(*)}}$ anomalies and $(g-2)_μ$ in an ${L_μ-L_τ}$ scenario

“…This actually makes dark matter physics strongly correlated with the physics of rare B-decays and anomalous magnetic moment of µ, where the role of new gauge boson Z µτ is extremely crucial. Moreover, it also helps us to evade the strong bound coming from the experiments of direct detection [109], indirect detection [145] and also from the collider on Higgs invisible branching [110] for the low mass scalar dark matter [146][147][148], where b b final state is the principal annihilation channel. Therefore, in spite of being a gauge singlet Z 2 -odd scalar field, the mixing with another Z 2 -odd field (part of an SU(2) L doublet) having nonzero L µ − L τ charge, makes the entire dynamics of our dark matter candidate ρ 1 strikingly different from the standard Scalar Singlet dark matter scenario [105][106][107][108].…”

“…10, where we have shown the allowed range of θ D with respect to M ρ 1 . However, in the high mass regime (M ρ 1 ≥ 500 GeV), large values of θ D > ∼ 0.3 rad are still allowed because for such large θ D , ρ 1 is mostly an SU(2) L doublet like state (similar to the Inert Doublet dark matter in high mass range [148][149][150]) which attains the present abundance of dark matter through co-annihilations with other Z 2 -odd fields into various bosonic final states (both vector and scalar). Moreover, we have also seen from the Fig.…”

Type I + II seesaw in a Two Higgs Doublet Model

“…In particular, we show that one can combine the type I and type II seesaw, and assess under which conditions one seesaw dominates over the other. Several type I+II seesaw studies have been performed in the past [40,[46][47][48][49], but in our work we discuss the type I, type II, and type I+II seesaw realizations embedded in the well motivated 2HDM-U (1) model which has become an experimental benchmark at the LHC [50][51][52], and investigate the implications for neutrino masses.…”