Related papers: Chasing Long-Lived Doubly Charged Scalars at Futur…
We consider a rather minimal extension of the Standard Model involving just one extra particle, namely a single $SU(2)_L$ singlet scalar $S^{++}$ and its antiparticle $S^{--}$. We propose a model independent effective operator, which yields…
The Inert Doublet Model (IDM) is one of the simplest extensions of the Standard Model (SM), providing a dark matter candidate. It is a two Higgs doublet model with a discrete $Z_2$ symmetry, that prevents the scalars of the second doublet…
We consider a neutrinophilic $U(1)$ extension of the Standard Model (SM) under which only a second Higgs doublet and SM singlet scalars and fermions are charged. The new gauge boson $Z'$ couples to SM minimally, generated by $Z-Z'$ mixing.…
We investigate phenomenological implications of a supersymmetric left-right model based on $SU(2)_L\times SU(2)_R\times U(1)_{B-L}\,$ gauge symmetry testable in the next generation linear colliders. We concentrate in particular on the…
Many new physics scenarios beyond the Standard Model often necessitate the existence of a (light) neutral scalar $H$, which might couple to the charged leptons in a flavor violating way, while evading all existing constraints. We show that…
In the context of a strongly coupled Electroweak Symmetry Breaking, composite triplet of heavy vectors degenerate in mass belonging to the $SU(2)_{L+R}$ adjoint representation may arise from a new strong interaction invariant under the…
We point out how future lepton colliders can provide unique insight into the scalar sector of TeV scale models for neutrino masses with local $B-L$ symmetry. Our specific focus is on the TeV scale left-right model, which naturally embeds…
Long-lived particles (LLPs) provide an unambiguous signal for physics beyond the Standard Model (BSM). They have a distinct detector signature, with decay lengths corresponding to lifetimes of around nanoseconds or longer. Lepton colliders…
We study a renormalizable theory that includes a heavy weak-singlet vectorlike lepton, $\tau^\prime$, that decays into a pseudoscalar boson and a tau lepton. We show that this can be the dominant decay mode of $\tau^\prime$ provided the…
We investigate the implications of a minimal $SU(2)$ gauge symmetry extension of the standard model at the LHC. To achieve the spontaneous symmetry breaking, a heavy Higgs doublet of the $SU(2)$ is introduced. To obtain an anomaly free…
We construct a new gauged $U(1)_\ell$ lepton number model which is anomaly-free for each SM generation. The active neutrino masses are radiatively generated with a minimal scalar sector. The phenomenology and collider signals are studied.…
Long-lived particles have become a new frontier in the exploration of physics beyond the Standard Model. In this paper, we present the implementation of four types of long-lived particle searches, viz. displaced leptons, disappearing track,…
Charged Higgs phenomenology and detection chance at future linear colliders through the production process $e^{-}e^{+} \ra H^{+}H^{-} \ra \tau^{+}\nu \tau \bar{\nu}$ is studied. Both charged Higgs bosons are considered to decay to $\tau\nu$…
We study the non-standard interactions of neutrinos with light leptonic scalars ($\phi$) in a global $(B-L)$-conserved ultraviolet (UV)-complete model. The model utilizes Type-II seesaw motivated neutrino interactions with an…
A search new phenomena giving rise to pairs of opposite electrically charged muons with impact parameters in the millimetre range is presented, using 139 fb$^{-1}$ of $\sqrt{s} = 13$ TeV $pp$ collision data from the ATLAS detector at the…
The diverse and distinct collider phenomenology of color-sextet scalars motivates thorough investigation of their effective couplings to the Standard Model at the LHC. Some of the more unique sextet signals involve not only jets but also…
The pattern of quantum numbers in the leptons and quarks indicate that precisely two fixed hypercharge splittings are observed in nature. The $|\Delta Y|=1$ splitting corresponds to the $SU(2)_L$ scalar and doublet spacing, indicative of…
This paper presents results of the first full simulation study addressing prospects for observation of long-lived particles (LLPs) with the International Large Detector (ILD), operating at the International Linear Collider (ILC) at…
Several extended supersymmetric models, motivated by either grand unification, or by neutrino mass generation, predict light doubly charged higgsinos. We study the production of a single doubly charged higgsino and its decay channels at the…
Color-sextet scalars could have an array of possible couplings to the Standard Model beyond their well known renormalizable couplings to quark pairs. The next-largest couplings these scalars might enjoy have mass dimension six, and some…