Related papers: Vector Leptoquarks Beyond Tree Level II: $\mathcal…
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…
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…
Leptoquarks (LQs) provide very promising solutions to the tensions between the experimental measurements and the SM predictions of $b\to s\ell^+\ell^-$ and $b\to c\tau\nu$ processes. In this case the LQ masses are in general at the TeV…
Motivated by the recent anomalies observed in semileptonic decays of B-mesons, the class of models denoted as "4321" is introduced and analysed. The importance of calculating next-to-leading-order (NLO) effects in performing precise…
Leptoquarks provide viable solutions to the flavour anomalies, i.e. they can explain the tensions between the measurements and the Standard Model predictions of the anomalous magnetic moment of the muon as well as $b\to s\ell^+\ell^-$ and…
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…
We present general formulas for the oblique-correction parameters $S$, $T$, $U$, $V$, $W$, and $X$ in a model of New Physics having arbitrary numbers of scalar leptoquarks of the five permissible types. We allow for a general mixing among…
We present a thorough investigation of the vector leptoquark hypothesis for a combined explanation of the $B$-physics anomalies. We analyze this hypothesis from a twofold perspective, taking into account recent results from $B$-physics…
Leptoquarks (LQs) have been extensively studied in the context of $B$ anomalies. When $U(1)_{L_\mu-L_\tau}$ is introduced to a scalar LQ model with the LQ $S_1$ charged under the new symmetry, $S_1$ primarily couples to the third-generation…
We point out that in extended supersymmetric models such as supersymmetric left-right models, it is possible to have leptoquarks that explain the HERA high $Q^2$ anomaly without giving up R-parity conservation. The leptoquarks belong to…
Scalar leptoquarks (LQ) with masses between 2 TeV and 50 TeV are prime candidates to explain deviations between measurements and Standard-Model predictions in decay observables of $b$-flavored hadrons (``flavor anomalies''). Explanations of…
We scrutinize the impact of various relevant scalar leptoquarks on the physical observables associated with the rare semileptonic decay processes of $B_s$ meson involving $b \to (u, c) l\bar \nu_l$ quark level transitions. We constrain the…
We analyse the constraints on scalar leptoquarks coming from radiative corrections to $Z$ physics. We perform a global fitting to the LEP data including the contributions of the most general effective Lagrangian for scalar leptoquarks,…
The recent measurements of lepton flavor university (LFU) violating observables in semileptonic $b \to c \ell \bar{\nu} $ and $b\to s\ell^+ \ell^-$ transitions by various experiments exhibit $(2-3)\sigma$ deviations from their corresponding…
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…
The anomalies in semileptonic $B$-decays are often attributed to new physics scenarios featuring leptoquark degrees of freedom. Attempts to accommodate all the deviations at once usually result in an elaborate model building way beyond the…
Motivated by the recent measurement of the lepton flavour nonuniversality ratio $R_{K^*}$ by the LHCb Collaboration, we study the implications of vector leptoquarks on the observed anomalies associated with the $\bar B \to \bar K^* l^+ l^-$…
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…
We extend previous computations of the second order QCD corrections to semileptonic b \to c inclusive transitions, to the case where the charged lepton in the final state is massive. This allows accurate description of b \to c \tau \bar…
Experimental data on $ R(D^{(*)}) $, $ R(K^{(*)}) $ and $ R(J/\psi) $, provided by different collaborations, show sizable deviations from the SM predictions. To describe these anomalies many new physics scenarios have been proposed. One of…