Related papers: Constraints on Heavy Neutral Leptons interacting w…
We consider an extension of the scalar sector of the Standard Model with a single complex Higgs triplet $X$. Such extensions are the most economic, model-independent way of generating neutrino masses through triplet interactions. We show…
We show that the addition of real scalars (gauge singlets) to the Standard Model can both ameliorate the little hierarchy problem and provide realistic Dark Matter candidates. To this end, the coupling of the new scalars to the standard…
To ascertain the new boson with mass near 125 {GeV} observed recently by ATLAS and CMS Collaborations to be the Standard Model Higgs, and to determine its intrinsic properties, more measurements on its various decay channels are still…
In this article, we study the interactions of stable, hadronizing new states, arising in certain extensions of the Standard Model. A simple model, originally intended for stable gluino hadrons, is developed to describe the nuclear…
In the traditional neutrinophilic two-Higgs doublet model ($\nu$2HDM), there is no non-standard neutrino interaction (NSI) as the interactions between the Standard Model fermions with neutrinos are negligibly small due to the tiny mixing of…
The simplest little Higgs model based on a SU(3) global symmetry contains a $SU(3)_{weak}$ triplet and a singlet per a generation in the lepton sector. A neutral component of the triplet and the singlet turn into a neutral vector-like…
Physics beyond the Standard Model (SM) may manifest itself as small deviations from the SM predictions for Higgs signal strengths at 125 GeV. Then, a plausible and interesting possibility is that the Higgs sector is extended and at the weak…
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…
We consider the collider phenomenology of a singlet Majoron model with softly broken lepton number. Lepton number is spontaneously broken when the real part of a new singlet scalar develops vacuum expectation value. With the additional soft…
Scalar singlets under the Standard Model gauge group appear naturally in many well-motivated New Physics scenarios, such as the composite Higgs models. Unlike the Higgs boson in the Standard Model, they can induce large flavour-changing…
We study a limit of the nearly-Peccei-Quinn-symmetric Next-to-Minimal Supersymmetric Standard Model possessing novel Higgs and dark matter (DM) properties. In this scenario, there naturally co-exist three light singlet-like particles: a…
We point out that the stringent lower bounds on the masses of additional electrically neutral and charged Higgs bosons crucially depend on the flavour structure of their Yukawa interactions. We show that these bounds can easily be evaded by…
We investigate non-standard neutrino interactions (NSIs) in the triplet seesaw model featuring non-trivial correlations between NSI parameters and neutrino masses and mixing parameters. We show that sizable NSIs can be generated as a…
We report new constraints and sensitivities to heavy neutral leptons (HNLs) with transition magnetic moments, also known as dipole-portal HNLs. This is accomplished using data from the T2K ND280 near detector in addition to the projected…
We consider an $SU(3)_L\otimes U(1)_N$ model for the electroweak interactions which includes extra charged leptons which do not mix with the known leptons. These new leptons couple to $Z^0$ only through vector currents. We consider…
Gauge singlet extensions of the Standard Model (SM) scalar sector may help remedy its theoretical and phenomenological shortcomings while solving outstanding problems in cosmology. Depending on the symmetries of the scalar potential, such…
Given the elusive nature of neutrinos, their self-interaction is particularly difficult to probe. Nevertheless, upper limits on the strength of such an interaction can be set by using data from terrestrial experiments. In this work we focus…
After the discovery of the Higgs boson with mass at approximately 125 $GeV$ at the LHC, many studies both from the theoretical and experimental sides have been performed to search for a new Higgs Boson lighter than the 125 $GeV$ Higgs…
Using an effective Lagrangian approach we analyze a generic Higgsless model with composite heavy fermions, transforming as SU(2)_{L+R} Doublets. Assuming that the Standard Model fermions acquire mass through mixing with the new heavy…
Standard thermal leptogenesis in the type-I seesaw model requires very heavy right-handed neutrinos (RHNs). This makes it hard to probe this scenario experimentally and results in large radiative corrections to the Higgs boson mass. In this…