Charged Higgs bosons in the extended supersymmetric scenario at the LHC

We investigate an extension of the Minimal Supersymmetric Standard Model (MSSM) containing a $SU(2)$ Higgs triplet of zero hypercharge and a gauge singlet. We focus on a scenario of this model which allows a light pseudoscalar and/or a scalar below $100$ GeV in the spectrum, consistent with the most recent data from the LHC and the earlier data from the LEP experiments. The triplet extension gives rise to two additional charged Higgs bosons which do not couple to fermions but can decay into $Z W^\pm$. The presence of a very light pseudoscalar opens $a_1 W^\pm$ decay mode for the light charged Higgs boson just like $Z_3$ symmetric singlet-extension (NMSSM). A triplet type charged Higgs can be produced via vector boson fusion at the tree-level which is absent in 2HDM and MSSM and NMSSM. If such charged Higgs boson is pair produced both $Z W^\pm$ and $a_1 W^\pm$ decay modes can be probed which can prove the existence of triplet and singlet both.Comment: 10 pages, 7 figures, contribution to LHCP 2016 conference proceeding

Distinguishing charged Higgs bosons from different representations at the LHC

Extending the Standard Model (SM) scalar sector via one or multiple Higgs field(s) in higher representation brings one or more charged Higgs bosons in the spectrum. Some of these gauge representations with appropriate hypercharge can bring up doubly charged Higgs boson and can be easily distinguished from the existing models with only singly charged Higgs boson. In this study we focus on distinguishing the singly charged Higgs bosons from different representations, viz. doublets and triplets of $SU(2)_L$ gauge group. We consider a supersymmetric extension of SM with a gauge singlet and $SU(2)_L$ triplet with $Y=0$ as a benchmark scenario with the possibility of rich phenomenology due to existence of light pseudoscalar for $Z_3$ symmetric superpotential. A detailed collider simulation considering all the SM backgrounds has been carried out in order to classify the final states which are favourable to charged Higgs boson from one particular representation than others. We show that such different representations can be probed an distinguished via looking at single charged Higgs boson phenomenology at the LHC with 14 TeV center of mass energy within $\sim 50$ fb$^{-1}$ of integrated luminosity.Comment: 28 pages, 14 figures, 14 tables. updated version with references reordere

Displaced lepton flavour violating signatures of right-handed sneutrinos in U(1)′ supersymmetric models

We consider a U(1)' extended supersymmetric model with a right-handed neutrino superfield which can generate light neutrino mass by Type I seesaw mechanism. The lighter superpartner of the right-handed neutrino could be the scalar dark matter. These right-handed sneutrinos can come from the decay of (Z) over tilde', superpartner of the extra gauge boson Z'. Left-right handed sneutrino mixings affect their decays further, giving rise to displaced "lepton flavour violating" signatures. A wino-like chargino NLSP (next to lightest supersymmetric particle) creates even more interesting decay topology. We investigate such displaced multi-leptonic final states with "lepton flavour violation" from the supersymmetric cascade decays of third generation squarks at the LHC

Perspectives on a Supersymmetric Extension of the Standard Model with a Y=0Y=0 Higgs Triplet and a Singlet at the LHC

We investigate a supersymmetric extension of the Minimal Supersymmetric Standard Model (MSSM), called the TNMSSM, containing a $SU(2)$ Higgs triplet $(\hat{T})$ of $Y=0$ hypercharge and a singlet superfields $(\hat{S})$ in the corresponding superpotential. The model can be viewed, equivalently, as an extension of the NMSSM with the addition of a $\hat{T}-\hat{S}$ interaction and of an extra coupling of the triplet to the two Higgs doublets of the NMSSM. In this scenario the Higgs particle spectrum at tree-level gets additional mass contributions from the triplet and singlet scalar components respect to the MSSM, which are particularly enhanced at low $\tan{\beta}$. We calculate the one-loop Higgs masses for the neutral physical Higgs bosons by a Coleman-Weinberg effective potential approach. In particular, we investigate separately the impact of the radiative corrections due to the electroweak, gauge-gaugino-higgsino, fermion-sfermion and Higgs self-interactions to the Higgs masses. Due to the larger number of scalars and of triplet and singlet couplings, the Higgs corrections can be larger than the strong corrections. This reduces the amount of fine-tuning required to fit the recent Higgs data. Using the expressions of the beta-functions of the model, we show that the large triplet singlet coupling remains perturbative up to $\sim10^{8-10}$ GeV. The model is also characterized by a light pseudoscalar in the spectrum, which is a linear combination of the triplet, doublet and singlet CP-odd components. We discuss the production and decay signatures of the Higgs bosons in this model, including scenarios with hidden Higgses, which could be investigated at the LHC in the current run.Comment: 39 pages, 37 figures, comments added for the published versio

Higgs bosons: discovered and hidden, in extended Supersymmetric Standard Models at the LHC

We investigate an extension of the Minimal Supersymmetric Standard Model (MSSM) containing a $SU(2)$ Higgs triplet of zero hypercharge and a gauge singlet. We focus on a scenario of this model which allows a light pseudoscalar and/or a scalar below $100$ GeV in the spectrum, consistent with the most recent data from the LHC and the earlier data from the LEP experiments. We analyze the exotic decay of the discovered Higgs $(h_{125})$ into two light (hidden) Higgs bosons present in the extension. The latter are allowed by the uncertainties in the Higgs decay $h_{125}\to WW^*$, $h_{125}\to ZZ^*$ and $h_{125}\to \gamma\gamma$. We have searched for such light Higgs bosons in the $2b+2\tau$, $\geq 3\tau$, $2b+2\mu$ and $2\tau+2\mu$ final states at the LHC with 13 and 14 TeV. A region of such parameter space can be explored with an integrated luminosity of 25 fb$^{-1}$ at the LHC.Comment: 12 pages, 10 figures, CORFUR2015. arXiv admin note: text overlap with arXiv:1506.0363

Phenomenology of Higgs bosons in inverse seesaw model with Type-X two Higgs doublet at the LHC

Type-X two Higgs doublet model is known to explain the muon $g-2$ anomaly with a relatively light charged Higgs boson at large $\tan\beta$. The light charged Higgs boson has been searched in the main $\tau \nu$ mode at the colliders. Invoking a scenario of inverse seesaw as the origin of neutrino masses and mixing, the charged Higgs boson can decay additionally to right-handed neutrinos which leads to interesting phenomenology. Considering generic lepton flavour violating signatures at the final states, a $5\sigma$ discovery can be achieved with the early data of LHC, at 14 TeV, for relatively large inverse seesaw Yukawa coupling $Y_N$. The very light pseudoscalar and charged Higgs boson mass reconstruction are performed using the new modes and the results look promising. The inverse seesaw Yukawa coupling is shown to be probed down to $Y_N \sim 0.2$ at HL LHC with 3000 fb$^{-1}$.Comment: 20 pages, 8 figures and 9 tables, reference adde