Related papers: Simplified models of vector $SU(4)$ leptoquarks at…
Building on our recent proposal to explain the experimental hints of new physics in $B$ meson decays within the framework of Pati-Salam quark-lepton unification, through the interactions of the $(3,1)_{2/3}$ vector leptoquark, we construct…
The Standard Model is extended by a SU(2)L singlet of vector leptoquarks. An additional SU(4) gauge symmetry between right-handed up quarks and right-handed leptons is introduced to render the model renormalizable. The arrangement is made…
A vector-like extension of the standard model for heavier quarks and leptons with $SU(2)\times U(1)$ gauge symmetry and only one Higgs doublet is examined. This scheme incorporates infinitely many fermions and avoids the appearance of a…
Lepton number as a fourth color is an intriguing theoretical idea which is combined with a possible left-right symmetry within the famous Pati-Salam (PS) model. In the conventional PS model, a spontaneous breaking of the PS gauge group down…
Models with massive vector leptoquarks, resulting from an $SU(4)$ gauge symmetry spontaneously broken at the TeV scale, are of great phenomenological interest given the current "anomalies" in semileptonic $B$ decays. We analyze the…
Several experiments revealed intriguing hints for lepton flavor universality (LFU) violating new physics (NP) in semi-leptonic $B$ meson decays, mainly in $b \to c \tau \nu$ and $b \to s \ell^+ \ell^-$ transitions at the $3-5\,\sigma$…
Extending previous work on this subject, we evaluate the impact of vector-like fermions at next-to-leading order accuracy in models with a massive vector leptoquark embedded in the $SU(4)\times SU(3)^\prime\times SU(2)_L\times U(1)_X$ gauge…
We propose a quark-lepton symmetric Pati-Salam (PS) model based on the gauge group $SU(2)_L \times SU(2)_R \times SU(4)_C$ with an $E_6$-inspired particle spectrum which naturally accommodates a multi-TeV leptoquark gauge boson…
We consider the phenomenological signatures of Simplified Models of Flavourful Leptoquarks, whose Beyond-the-Standard Model (SM) couplings to fermion generations occur via textures that are well motivated from a broad class of ultraviolet…
The low-energy manifestations of a minimal extension of the electroweak standard model based on the quark-lepton symmetry $SU(4)_V \otimes SU(2)_L \otimes G_R$ of the Pati--Salam type are analyzed. Given this symmetry the third type of…
I report the recent studies\cite{1,2} on the low--energy manifestations of a minimal extension of the Standard Model based on the quark-lepton symmetry $SU(4)_V \otimes SU(2)_L \otimes G_R$ of the Pati-Salam type. Given this symmetry the…
Recently reported anomalies in various $B$ meson decays and also in the anomalous magnetic moment of muon $(g-2)_\mu$ motivate us to consider a particular extension of the standard model incorporating new interactions in lepton and quark…
The Standard Model (SM) is amended by one generation of quarks and leptons which are vector-like (VL) under the SM gauge group but chiral with respect to a new $\mathrm{U}(1)_{3-4}$ gauge symmetry. We show that this model can simultaneously…
We consider the Standard Model (SM) with the addition of a $\mathrm{U(1)^\prime}$ gauge symmetry and a complete fourth family of quarks and leptons which are vector-like with respect to the full $\mathrm{SU(3)_C}\times \mathrm{SU(2)_L}…
The vector leptoquark representation, $U_\mu = (3,1,2/3)$, was recently identified as an exceptional single mediator model to address experimental hints on lepton flavour universality violation in semileptonic $B$-meson decays, both in…
In this talk, we discuss a simplified version of a recently proposed twin Pati-Salam (PS) theory of flavour broken to the $G_{4321}$ gauge group at high energies, then to the Standard Model at low energies, yielding a TeV scale vector…
The collection of a few anomalies in semileptonic $B$-decays, especially in $b\rightarrow c \tau \bar{\nu}$, invites to speculate about the emergence of some striking new phenomena, perhaps interpretable in terms of a weakly broken $U(2)^n$…
In this paper, we show an explicit way to realize a TeV-scale vector leptoquark from the Pati-Salam (PS) unification with extra vectorlike families. The leptoquark mass is constrained to be heavier than PeV-scale by the measurement of a…
The Standard Model fermion sector is enlarged by either one light singlet vector-like down-type quark or one light vector-like lepton doublet, which might be accommodated within a five-dimensional representation of SU(5). At low energies…
We address the recent anomalies in semi-leptonic $B$-meson decays using a model of fermion masses based on the $U(2)$ flavor symmetry. The new contributions to $b \to s \ell \ell$ transitions arise due to a tree-level exchange of a…