Related papers: Analysis of $\Lambda_{b} \rightarrow$ $\Lambda \mu…
In a recent paper, 8 semileptonic parameters were defined to specify the most general Lorentz-invariant spin correlation functions for 2-body tau decays. These parameters can be used to search for anomalous longitudinal-versus transverse…
The semileptonic decays $\bar{B}\to D(D^*)\pi\ell\bar{\nu}$ are analyzed by heavy quark and chiral symmetries. The branching ratio is of order of a few percent for $\dpi$, but it is much smaller for $\dstar$, of order $10^{-4}-10^{-5}$. The…
The Xi^0 muon semi-leptonic decay has been observed for the first time with nine identified events using the KTeV beam line and detector at Fermilab. The decay is normalized to the Xi^0 beta decay mode and yields a value for the ratio of…
Models where the baryon (B) and lepton (L) numbers are local gauge symmetries that are spontaneously broken at a low scale are revisited. We find new extensions of the Standard Model which predict the existence of fermions that carry both…
In terms of ${\cal P}_{c1,c2}={\cal P}_c(4380,4450)^+$ as the hidden charm pentaquark states to consist of $c\bar c uud$, we study the semileptonic $\Lambda_b\to ({\cal P}_{c1,c2}\to)J/\psi p \ell^-\bar \nu_\ell$ decays. In our discussion,…
The flavor changing rare decay $B\to K^{*}(\to K\pi)\ell^+\ell^-$ is one of the most studied modes due to its sensitivity to physics beyond the standard model and several discrepancies have come to light among the plethora of observables…
We present an investigation of the lepton energy distributions in the inclusive semileptonic weak decays of heavy baryons performed within a relativistic quark model formulated on the light front (LF). Using the heavy-quark LF distribution…
The nonleptonic two-body $\Lambda_b\rightarrow \Lambda\psi $ decays with $\psi=J/\psi$ or $\psi(2S)$ are investigated based on the perturbative QCD approach. These are color-suppressed processes in which the nonfactorizable contributions…
We study the semileptonic decays of $B_{cc}$ ${\rightarrow}$ $B_c\ell^+\nu_\ell$ with the bag model, where $\ell$ = $(e, \mu)$, $B_{cc}$ = $(\Xi_{cc}^{++}$, $\Xi_{cc}^+$, $\Omega_{cc}^+$), and $ B_c$ are the singly charmed baryons with…
This study investigates the influence of the fourth generation quarks on the double lepton polarizations in \Lambda_b --> \Lambda \ell^+ \ell^- decay by taking |V^\ast_{t's}V_{t'b}|= 0.005,0.01,0.02,0.03 with phase…
We study the implication of R-parity violating Rp Minimal Supersymmetric Standard Model (MSSM) model in lepton polarization asymmetry ALP in B l l(bar) decays . The analysis show that the ALP is significant in a certain phenomenological…
The existence of R-parity in supersymmetric models can be naturally explained as being a discrete subgroup of gauged baryon minus lepton number (B-L). The most minimal supersymmetric B-L model triggers spontaneous R-parity violation, while…
In this work we study the implication of the fourth generation standard model (SM4) to the single and double lepton polarization asymmetries in the $B\rightarrow K^{\ast}\ell^{+}\ell^{-}$, $(l=\mu,\tau)$ decay. To see the variation in the…
We investigate the weak semileptonic decays of the charmonium $J/\psi$ and bottomonium $\Upsilon(1S)$ into a pseudoscalar meson, namely, the $J/\psi\to D_{(s)}\ell\bar{\nu}_\ell$ and $\Upsilon(1S)\to B_{(c)}\ell\bar{\nu}_\ell$ decays. We…
Using $4.5~\mathrm{fb}^{-1}$ of $e^+e^-$ annihilation data samples collected at the center-of-mass energies ranging from 4.600~GeV to 4.699~GeV with the BESIII detector at the BEPCII collider, a first study of the semileptonic decays…
We present an investigation of the Isgur-Wise form factor relevant for the semileptonic decay Lambda_b -> \Lambda_c + l nu_l performed within a light-front constituent quark model. Adopting different baryon wave functions it is found that…
Searches for $B$ mesons decaying to final states containing a baryon and a lepton are performed, where the baryon is either $\Lambda_c$ or $\Lambda$ and the lepton is a muon or an electron. These decays violate both baryon and lepton number…
The exclusive semileptonic heavy baryon decay \Lambda_b\to p l\bar\nu is investigated using light-cone sum rule method in both full QCD and HQET. The form factors describing the decay are calculated and used to predict the decay width and…
We investigate the decay of $\Lambda_b\to\Lambda\nu\bar{\nu}$ with the polarized baryons of $\Lambda_b$ and $\Lambda$. With the most general hadronic form factors, we first study the decay branching ratio and then derive the longitudinal,…
We study the effect of scalar leptoquarks on some rare decays of $B_s$ mesons involving the quark level transition $b\rightarrow s$ $l^{+} l^{-}.$ In particular we consider the decays $B_{s} \rightarrow \mu^{+} \mu^{-}$, $\bar B_d^0 \to X_s…