Related papers: Vector Leptoquarks Could Be Rather Light?
The vertex corrections to the leptonic partial widths of the $Z$ induced by leptoquarks that couple leptons to the top quark are considered. We obtain stringent bounds on the parameter space of the masses and Yukawa couplings of these…
Recently, several anomalies in flavor physics have been observed, and it was noticed that leptoquarks might account for the deviations from the Standard Model. In this work, we examine the effects of new physics originating from a scalar…
We present constraints on products of two leptoquark (LQ) coupling constants. The bounds are obtained from meson decays, in particular leptonic \pi, K, D, D_s, B, B_s decays. Furthermore semileptonic meson decays and mixing in neutral meson…
If electroweak symmetry breaking arises via strongly-coupled physics, the observed suppression of flavour-changing processes suggests that fermion masses should arise via mixing of elementary fermions with composite fermions of the strong…
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…
We address the issue of model dependence of partial proton decays due to exchange of a single scalar leptoquark within a minimal viable SU(5) framework. The minimal setup predicts a flavor part of the proton decay widths for channels with…
In a vector-like extension of the minimal standard model with mirror fermions leptoquarks can be bound states of fermion-mirror-fermion pairs held together by a new strong interaction at the TeV scale. The small couplings of leptoquarks to…
Searches for first generation scalar and vector leptoquarks, and for squarks in R-parity violating SUSY models with the direct decay of the squark into Standard Model particles, have been performed using e+e- collisions collected with the…
Two models incorporating different forms of spontaneously broken quark-lepton symmetry are discussed. Both models are constructed so that quark-lepton symmetry can be broken at as low an energy scale as phenomenology allows, thus maximising…
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…
We derive bounds on vector leptoquarks coupling to the first generation, using data from low energy experiments as well as from high energy accelerators. Similarly to the case of scalar leptoquarks, we find that the strongest indirect…
The contributions of scalar and gauge leptoquarks into widths of $K^0_L \to e^{\mp} \mu^{\pm}$, $B^0 \to e^{\mp} \tau^{\pm}$ decays are calculated in the models with the vectorlike and chiral four color symmetry and with the Higgs mechanism…
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…
The contributions of the scalar leptoquark doublets into widths of the $K^0_L \to e^{\mp} \mu^{\pm}$, $B^0 \to e^{\mp} \tau^{\pm}$ decays are calculated in MQLS model with Higgs mechanism of the quark-lepton mass splitting. The resulted…
Leptoquarks with mass in the region of $550-650$ GeV are a possible candidate for the recent excess seen by CMS in the $eejj$ and $e \nu jj$ channels. We discuss models where leptoquarks decay primarily to dark matter and jets, thereby…
The results of a previous search by the CMS Collaboration for squarks and gluinos are reinterpreted to constrain models of leptoquark (LQ) production. The search considers jets in association with a transverse momentum imbalance, using the…
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…
We propose a chiral Pati-Salam theory based on the gauge group $SU(4)_C\times SU(2)_L\times SU(2)_R$. The left-handed quarks and leptons are unified into a fundamental representation of $SU(4)_C$, while right-handed quarks and leptons have…
Recent hints for lepton-flavor non-universality in $B$-meson decays can be interpreted as hints for the existence of leptoquarks. We show that scalar leptoquarks unavoidably arise in grand unified theories, using the well-known Pati-Salam…
We construct a model of quark-lepton unification at the TeV scale based on an $SU(4)$ gauge symmetry, while still having acceptable neutrino masses and enough suppression in flavor changing neutral currents. An approximate $U(2)$ flavor…