相关论文: $R_2$ as a single leptoquark solution to $R_{D^{(*…

If the leptoquarks proposed to account for the intriguing anomalies observed in the $B$-meson decays, $R_{D^{(\ast)}}$ and $R_{K^{(\ast)}}$, as well as in the anomalous magnetic moment of the muon, $(g-2)_\mu$, can be embedded into the…

We consider lepton flavor violating Higgs decay, specifically $h \to \mu\tau$, in a leptoquark model. We introduce two scalar leptoquarks with the $SU(3)_c \times SU(2)_L \times U(1)_Y$ quantum numbers, $(3,2,7/6)$ and $(3,2,1/6)$, which do…

Right-handed neutrinos $\nu_R$ play a crucial role in flavor-changing neutral-current processes with missing energy, such as $b\to s + \slashed{E} $ and $d\to s + \slashed{E} $, where Belle-II reports unexpectedly large branching fraction…

The long-standing anomaly in the anomalous magnetic moment of the muon indicates the presence of chirality violating new physics contributions. A possible solution involves scalar leptoquarks with left- and right-handed couplings to the top…

We investigate the exclusive rare semileptonic decays $ B_c \to D_{s}^{(*)}\,(\ell \ell, \nu \bar{\nu})$ induced by neutral current transition $b \to s (\ell \ell,\nu \bar{\nu})$ in the presence of non-universal $Z^{\prime}$, scalar and…

The most efficient way to extend the Standard Model of particle theory so that it accommodates the observed B anomalies is the hypothesis of a leptoquark which is a color-triplet weak-singlet boson with electric charge $Q=+\frac{2}{3}$. We…

We study potential New Physics effects in the $\bar B \to D^{(*)} \tau \bar\nu$ decays. As a particular example of New Physics models we consider the class of leptoquark models and put the constraints on the leptoquark couplings using the…

We present an economical model where an $S^{}_1$ leptoquark and an anomaly-free $U(1)^{}_X$ gauge symmetry with $X = B^{}_3-2L^{}_\mu/3-L^{}_\tau/3$ are introduced, to account for the muon anomalous magnetic moment $a^{}_\mu \equiv…

Leptoquark (LQ) models can be the solution to the $(g-2)_{\mu}$ anomaly because of the chiral enhancements. In this work, we consider the models extended by the LQ and vector-like quark (VLQ) simultaneously, which can be used to explain the…

Leptoquarks provide some of the simplest explanations to the hints of lepton flavor non-universality in $B$ decays. In particular, a new confining gauge group can provide a natural and appealing origin for the leptoquarks. So far, direct…

Flavor symmetries successfully explain lepton and quark masses and mixings yet it is usually hard to distinguish different models that predict the same mixing angles. Further experimental input could be available, if the agents of flavor…

The puzzle of $R(D^{(*)})$ associated with $B\to D^{(*)}\tau\nu$ decay is addressed in the two-HIggs-doublet model. An anomalous coupling of $\tau$ to the charged Higgs is introduced to fit the data from BaBar, Belle, and LHCb. It is shown…

We investigate the $R_{D}$ and $R_{D^*}$ anomalies in the context of non-minimal $SU(5)$, where Higgs sector is extended by adjoint 45-dimensional multiplet. One of the light spectrum of this model could be the scalar triplet leptoquark…

Most of the popular explanations of the observed anomalies in the semileptonic $B$-meson decays involve TeV scale Leptoquarks (LQs). Among the various possible LQ models, two particular LQs -- $S_{1}(3, 1, 1/3)$ and $U_{1}(3, 1, 2/3)$ seem…

Rare $K \to \pi \nu \bar \nu$ decays, being dominated by short distance contributions within the Standard Model (SM), open a window for New Physics (NP) searches at low energies. The $ K \to \pi \nu \bar\nu $ branching ratios are expected…

Leptoquarks have been suggested to solve a variety of discrepancies between the expected and observed phenomenon. In this paper, we show that the scalar doublet Leptoquark with Hypercharge 7/6 can simultaneously explain the recent…

Semileptonic and leptonic B decays are analyzed in the framework of the relativistic quark model. Special attention is payed to the decays involving $\tau$ lepton. It is found that the calculated particular decay branching fractions are…

We examine various scenarios in which the Standard Model is extended by a light leptoquark state to solve for one or both $B$-physics anomalies, viz. $R_{D^{(\ast)}}^\mathrm{exp}> R_{D^{(\ast)}}^\mathrm{SM}$ or/and…

Several experiments have measured a deviation in $B\to D^{(*)}$ semileptonic decays, that point to new physics at the TeV scale violating lepton flavor universality. A scalar leptoquark $S_1$, with a suitable structure of couplings in…

Motivated by the recent experimental progress on the $B$-meson decay anomalies (in particular the angular observables in $B\to K^\ast\mu\mu$), we rely on a simplified-model approach to study the prospects of vector leptoquarks in what…