Related papers: Charged Scalar Particles and $\tau$ Leptonic Decay
The Standard Model, if extended to the energy scale of $\mathcal{O}(1)$ TeV, the known particle spectrum could be augmented with a scalar leptoquark. Within this minimally extended framework, explaining the anomalous magnetic moment and…
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…
Popular extensions of the standard model of particle physics feature new fields and symmetries which could, for example, dynamically generate neutrino masses from $B-L$ spontaneous symmetry breaking. If a new light scalar that decays into…
We explore a gauged $U(1)_{B-L}$ extension of standard model with inclusion of three right-handed neutrinos of exotic $B-L$ charges to cancel the gauge anomaly. Non-trivial transformation of new particles under $B-L$ symmetry forbids the…
We study decays of superheavy particles $X$ into leptons. We show that they initiate cascades similar to QCD parton jets, if $m_X\gsim 10^6$ GeV. Electroweak cascading is studied and the energy spectra of the produced leptons are calculated…
The present work introduces new scalar and fermionic degrees of freedom to the Standard Model. While the scalar sector is augmented by a complex scalar triplet and a doubly charged scalar singlet, the fermionic sector is extended by two…
The \tau \to \omega,\phi \pi^- \nu_\tau decays of the \tau lepton are studied using the method of phenomenological SU(3) * SU(3) chiral Lagrangians. It is shown that the obtained value for the \tau \to \phi \pi \nu_\tau decay probability is…
We demonstrate that in a recently proposed unified leptoquark model based on the gauge group $SU(4)_C\times SU(2)_L \times U(1)_R$ significant deviations from the Standard Model values of $R_K$ and $R_{K^*}$ can be accommodated without any…
A colored weak singlet scalar state with hypercharge 4/3 is one of the possible candidates for the explanation of the unexpectedly large forward-backward asymmetry in t tbar production as measured by the CDF and D0 experiments. We…
The supersymmetric decays of the top quark into charged Higgs plus bottom, $\thb$, and into the supersymmetric partner of the top (${\wti u}_1$) plus the lightest neutralino (${\wti \chi}_1^0$), $\tstopneu$, are discussed within the…
We consider a neutrino mass generating model which employs a scalar leptoquark, $\Delta$, and a scalar diquark, $S$. The new scalars $\Delta$ and $S$ carry the standard model $SU(3)_c\times SU(2)_L\times U(1)_Y$ quantum numbers $(3,1,-1/3)$…
We consider a simple scalar dark matter model within the frame of gauged $L_{\mu}-L_{\tau}$ symmetry. A gauge boson $Z'$ as well as two scalar fields $S$ and $\Phi$ are introduced to the Standard Model (SM). $S$ and $\Phi$ are SM singlet…
We discuss a possibility to explain the LHC diphoton excesses at $750$GeV by the new scalar $X$ that couples to the gauge bosons through the loop of new massive particles with Standard Model charges. We assume that the new particles decay…
A simple extension of the Standard Model (SM), based on the gauge group $SU(3)_C\otimes SU(3)_L\otimes U(1)_Y$ with $Y$ being the hypercharge, is considered. We show that, by imposing an approximate global $SU(2)_L\times SU(2)_R$ custodial…
Analytic expressions are given for the $\tau$ decays into three charged leptons, $\tau\rta \ell\ell\overline \ell\nu_\tau\overline \nu_\ell$, where the $\ell$ are combinations of electrons and muons, and for the radiative decays $\tau\rta…
The radiative leptonic $B_{c}\to\tau\bar{\nu_{\tau}}\gamma$ decay is analysed in context of 2HDM. It is shown that with large values of $tan\beta$, the contributions of Model II to the decay rate exceeds considerably the Standard Model…
The polarization effects in the one-meson radiative decay of the polarized $\tau$ lepton, $\tau^-\to\pi^-\gamma\nu_{\tau}$, have been investigated. We present the analytical results for the $t-$distribution of the partial differential…
We study the one-loop induced muon number processes when the standard model is minimally extended to include a $\rm SU(2)$ singlet of a charged scalar $h^+$ and a neutral fermion $N$. We find that $\mu \rightarrow e \gamma$ is more…
During the past few years, hints of Lepton Flavour Universality (LFU) violation have been observed in $b \to c \tau \bar\nu$ and $b \to s \ell^+ \ell^-$ transitions. Recently, the $D^*$ and $\tau$ polarization fractions $P_L^{D^*}$ and…
Together with any Beyond the Standard Model ultraviolet complete, renormalizable model, one or several exotic particles are usually hypothesized. $C\!P$-even neutral and doubly-charged scalars are common, well known examples which can…