相关论文: Lepton transverse polarization in the B --> D l nu…
We study the longitudinal, transverse, and normal polarization components of the tau lepton in the decays $\bar{B}^0 \to D^{(\ast)} \tau^- \bar\nu_{\tau}$ and discuss their role in searching for new physics (NP) beyond the standard model…
We study the lepton polarization asymmetries in the radiative leptonic B decays of $B^+\to l^+\nu_{l}\gamma$ and $B^+_{c}\to l^+\nu_{l}\gamma$. We concentrate on the transverse component of the $\tau$ lepton asymmetries in the tau decay…
The muon transverse polarization in the $K^+ \to \mu^+ \nu \gamma$ process induced by the electromagnetic final state interaction is calculated in the framework of Standard Model. It is shown that one loop contributions lead to a…
Decays of B mesons into final states containing a tau lepton are sensitive to new charged-current interactions that break lepton-flavor universality. These decays have been studied only at e+e- colliders, where the low-background…
The effective Hamiltonian for the decay $b\to s l^+ l^-$ predicts a characteristic polarization for the final state lepton, which can serve as an important test of the underlying theory. The lepton polarization has, in addition to a…
We calculate the transverse muon polarization in the decay $K^{\pm}\to\pi^0\mu^{\pm}\nu$ induced by the electromagnetic two-photon final-state interaction. For the central part of the Dalitz plot the typical value of this polarization is…
We study the potential of the measurement of the transverse muon polarization P_T in the K->mu nu gamma decay with the sensitivity of \delta P_T ~ 10^{-4}. It is shown that the forthcoming experiment can measure the contribution of the…
In this paper transverse positron polarization in the $\mu^+ \to e^+ \bar {\nu_{\mu}} \nu_e$ decay in the framework of SM is considered. It is shown that the final state interaction effect leads to nonzero transverse polarization. Numerical…
The T violating transverse muon polarizations in $K^+\to \pi^0\mu^+\nu$ and $K^+\to \mu^+\nu\gamma$ decays due to tensor interactions are studied. The magnitudes of these polarizations over the allowed phase space are presented.
The transverse lepton polarization asymmetry in pi_l2gamma decays may probe T-violating interactions beyond the Standard Model. Dalitz plot distributions of the expected effects are presented and compared to the contribution from the…
We report the first measurement of the $\tau$ lepton polarization $P_\tau(D^*)$ in the decay $\bar{B} \rightarrow D^* \tau^- \bar{\nu}_\tau$ as well as a new measurement of the ratio of the branching fractions $R(D^{*}) = \mathcal{B}(\bar…
This article summarizes recent developments in $B\to D^{(\ast)}\tau\nu$ decays. We explain how to extract the tau lepton's production properties from the kinematics of its decay products. The focus is on hadronic tau decays, which are most…
We investigate the longitudinal lepton polarization asymmetry in the exclusive processes $B\to K l^+l^-$ and $B\to K^* l^+l^-$. We include both short and long-distance contributions to the asymmetry in our discussions. We find that average…
We report the first measurement of the $\tau$ lepton polarization in the decay ${\bar B} \rightarrow D^* \tau^- {\bar\nu_{\tau}}$ as well as a new measurement of the ratio of the branching fractions $R(D^{*}) = \mathcal{B}({\bar B}…
We study the longitudinal polarization of the tau lepton in B -> D tau nu decay. After discussing possible sensitivities of tau decay modes to the tau polarization, we examine the effect of charged Higgs boson on the tau polarization in B…
Longitudinal lepton polarization asymmetry in B_q -> l l (q = d, s$ and l = e, mu, tau) decays is investigated. The analysis is done in a general manner by using the effective operators approach. It is shown that the longitudinal lepton…
We show that the transverse polarization asymmetry of the $\tau$-lepton in the decay $t\rightarrow b \tau \nu$ is extremely sensitive to CP violating phases arising from the charged Higgs exchange in the Weinberg model of CP…
We demonstrate that polarization measurements in exclusive semileptonic B decays are powerful tools for unraveling non-standard model sources of T-violation. Measurements of the transverse polarization of the tau lepton in the B to D tau nu…
We give a model-independent analysis of CP violating lepton polarization in the exclusive semileptonic B decay of $B\to D^{(*)}\ell\bar\nu$ including dimension six four-fermion tensor interactions at the heavy quark limit. It is shown that…
A first measurement of the average polarisation P_tau of tau leptons produced in e+e- annihilation at energies significantly above the Z resonance is presented. The polarisation is determined from the kinematic spectra of tau hadronic…