Related papers: Extra Quarks and Bileptons in BSM Physics in a $33…
We study the potential effect of anomalous couplings of the third generation quarks to gauge bosons in rare B decays. We focus on the constraints from flavor changing neutral current processes such as $b\to s\gamma$ and $b\to s…
We analyze the collider signatures of models with a vector-like top-prime quark and a massive color-octet boson. The top-prime quark mixes with the top quark in the Standard Model, leading to richer final states than ones that are…
We model tri-bimaximal lepton mixing from first principles in a way that avoids the problem of the vacuum alignment characteristic of such models. This is achieved by using a softly broken A4 symmetry realized with an isotriplet fermion,…
We have searched for evidence of physics beyond the standard model in events that include an energetic photon and an energetic b-quark jet, produced in 85pb of ppbar collisions at 1.8 TeV at the Tevatron Collider at Fermilab. This…
Results are reported from a search for physics beyond-the-standard-model, such as supersymmetry, in final states with at least three charged leptons, in any combination of electrons or muons. The data sample corresponds to an integrated…
Type-II seesaw is a simple scenario in which Majorana neutrino masses are generated by the exchange of a heavy scalar electroweak triplet. When endowed with additional heavy fields, such as right-handed neutrinos or extra triplets, it also…
In this presentation an account of the multi-lepton (electrons and muons) anomalies at the LHC is given. These include the excess production of opposite sign leptons with and without b-quarks, including a corner of the phase-space with a…
We consider the production at the LHC of exotic composite leptons of charge Q=+2e. Such states are allowed in composite models which contain extended isospin multiplets (Iw=1 and Iw=3/2). These doubly charged leptons couple with Standard…
We perform a detailed study of the $\text{b} \to \text{c} \tau \nu$ and $\text{b} \to \text{s} l^+ l^-$ processes in a minimal flipped 331 model based on the $SU(3)_C\times SU(3)_L\times U(1)_N$ gauge symmetry. The non universal $SU(3)_L…
Beyond the Standard Model scenarios introduce additional scalar and fermion multiplets, which influence neutrino mass generation mechanisms and yield distinctive collider signatures. This work focuses on a particular scenario involving a…
Four models are considered which contain heavy leptons beyond the three families of the standard model. Two are fourth-generation extensions of the standard model in which the right-handed heavy leptons are either isosinglets or in an…
An inclusive search for nonresonant signatures of beyond the standard model (SM) phenomena in events with three or more charged leptons, including hadronically decaying $\tau$ leptons, is presented. The analysis is based on a data sample…
This paper explores a simplified extension of the standard model featuring a neutral fermion quintuplet and a scalar quadruplet, which together generate neutrino masses through tree and loop level mechanisms. The quintuplet fermions decay…
Within the framework of supersymmetry, the particle content is extended in a way that each Higgs doublet is in a full generation. Namely in addition to ordinary three generations, there is an extra vector-like generation, and it is the…
We present leading-order (LO) cross sections for the production of three top quarks ($tt\tb$,$t\tb\tb$) at the Large Hadron Collider (LHC). We find a total LO cross section for triple-top production in the Standard Model of $\sigma \approx…
After a brief review of the inclusive and exclusive rare semileptonic decays of B mesons in the standard model (SM), an overview of recent theoretical developments in this field is given. New physics effects on various observables such as…
Sfermion masses and eigenstates in the supersymmetric economical 3-3-1 model are studied. By lepton number conservation, the exotic squarks and superpartners of ordinary quarks are decoupled. Due to the fact that in the 3-3-1 models, one…
We calculate the decay widths and branching ratios of the extra neutral boson $Z^{\prime}$ predicted by the 331 bilepton model in the framework of two different particle contents. These calculations are performed taken into account oblique…
In the so-called 331-models the gauge anomalies cancel only if there are three generations of fermions. This requires one of the quark generations to be in a different representation than the other two. But which generation is treated…
Large fermionic multiplets appear in different extensions of the Standard Model (SM), which are essential to predict small neutrino masses, relic abundance of the dark matter (DM) and the measured value of muon anomalous magnetic moment…