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The contributions of the chiral gauge leptoquarks $V^{L,R}$ induced by the chiral four color quark-lepton symmetry to the branching ratios of $ K_L^0, B^0, B_s to l_1 , l_2 $ decays are calculated and analysed using the general parametrizations of the fermion mixing matrices in the leptoguark currents. From the current experimental data on these decays under assumption $ m_{V^L} ll m_{V^R} $ the lower mass limit $ m_{V^L} cos{gamma_L} > 5.68 ,, mbox{TeV}$ is found, which in particular case of equal gauge coupling constants gives $ m_{V^L} > 8.03 ,, mbox{TeV} $. The branching ratios of the decays under consideration predicted by the chiral gauge leptoquarks are calculated and analysed in dependence on the leptoquark masses and the mixing parameters. It is shown that in consistency with the current experimental data these branching ratios for $ B_s, B^0 to mu e $ decays can be close to their experimental limits and those for $ B_s, B^0 to tau e, tau mu $ decays can be of order of~$10^{-7}$. The calculated branching ratios will be useful in the further experimental searches for these decays.
In this work, we analyze the semi-leptonic decays $bar B^0/D^0 to (a_0(980)^{pm}topi^{pm}eta) l^{mp} u$ within light-cone sum rules. The two and three-body light-cone distribution amplitudes (LCDAs) of the $B$ meson and the only available two-body L
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 mixing in the int
The recent observation of the mass difference in $B_s$ system seems to be not in complete agreement with the corresponding standard model value. We consider the model with an extra vector like down quark to explain this discrepancy and obtain the con
Inclusive semileptonic B_s^0 -> X^+ l^- u decays are studied for the first time using a 23.6 fb^{-1} data sample collected on the Y(5S) resonance with the Belle detector at the KEKB asymmetric energy e^+ e^- collider. These decays are identified by
We analyze the mixing between $Sigma^0$ and $Lambda^0$ based on the baryon masses. We distinguish the contributions from QCD and QED in the baryon mass splittings. We find that the mixing angle between $Sigma^0$ and $Lambda^0$ is $(2.07pm 0.03)times