Related papers: Measurement of tau polarization in e+ e- annihilat…
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 report the first measurement of the $D^{\ast -}$ meson polarization in the decay $B^0 \to D^{*-} \tau^+\nu_{\tau}$ using the full data sample of 772$\times 10^6$ $B\bar{B}$ pairs recorded with the Belle detector at the KEKB…
Energy and angular distributions of the tau decay products in the CERN-to-Gran Sasso $\nu_\tau$ appearance experiments are studied for the decay modes $\tau\to\pi\nu$ and $\tau\to l\bar\nu\nu$ (l=e or mu). We find that the decay particle…
We present a study for the measurement of of radiative decays, tau -> l gamma nu nu, l=e, mu, and tau -> pi gamma nu using 500 fb-1 of electron-positron annihilations recorded by the BaBar detector at the PEP-II asymmetric B-factory.
The first measurement of inclusive J/psi polarization at mid-rapidity (|y^{J/psi}| < 0.8) in 200 GeV Ru+Ru and Zr+Zr collisions at sqrt(s_NN) = 200 GeV with the STAR experiment at RHIC is presented. J/psi mesons are reconstructed through…
The electromagnetic and weak dipole moments of the Tau-lepton have been measured by experiments at e+e- colliders. Data samples of e+e- --> tau+tau-, e+e- --> tau+tau- gamma and e+e- --> e+e-tau+tau- events collected at centre-of-mass…
With data samples collected with the BESIII detector at seven energy points at $\sqrt{s}= 3.68 - 3.71$ GeV, corresponding to an integrated luminosity of 333 pb$^{-1}$, we present a study of the $\Lambda$ transverse polarization in the…
A method for measuring the average longitudinal polarization of the electron beam at an electron-positron collider operating near the $J/\psi$ resonance is proposed. The method utilizes the differential cross-section of $J/\psi\to…
Semileptonic decays of polarised $\tau$ leptons are investigated. Predictions for the rate, based on CVC and chiral Lagrangians, are contrasted with experiments. Predictions for the angular distributions of three meson final states are…
Rare $B$ decays provide an opportunity to probe for new physics beyond the Standard Model. In this paper, we propose to measure the tau polarization in the inclusive decay $B\to X_s\tau^+\tau^-$ and discuss how it can be used, in…
We investigate the spin polarization of \tau^{\pm} leptons produced in \nu_{\tau} and \bar{\nu}_{\tau} nucleon scattering via charged currents. Quasi-elastic scattering, \Delta resonance production and deep inelastic scattering processes…
We discuss a few possible strategies for measuring the polarization of the $\Lambda_{\mathrm{b}}$ baryons produced in $e^+e^-$-annihilation at the $\mathrm{Z}$ resonance through their inclusive semileptonic decays. After reviewing the…
A novel method for the direct measurement of the elusive magnetic and electric dipole moments of the tau lepton is presented. The experimental approach relies on the production of tau+ leptons from Ds+ -> tau+ nu_tau decays, originated in…
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 excitation curve for the $\tau^+ \, \tau^-$ production in electron positron annihilation near the threshold is revisited with the aim of updating and extending a previous work. We find that the corrections of the relative magnitude…
We search for lepton flavour violating events (e mu, e tau and mu tau) that could be directly produced in e+e- annihilations, using the full available data sample collected with the OPAL detector at centre-of-mass energies between 189 GeV…
We perform a measurement of the tau -> l gamma nu anti-nu (l = e, mu) branching fractions for a minimum photon energy of 10 MeV in the tau rest frame, using 431fb^-1 of e^+e^- collisions collected at the center-of-mass energy of the…
In this work we will study the polarizations of both leptons ($\tau$) in the decay channel $B\to K^* \tau^- \tau^+$. In the case of the dileptonic inclusive decay $B\to K^* \ell^- \ell^+$, where apart from the polarization asymmetries of…
We studied the radiative muon decay $\mu^+ \to e^+\nu\bar{\nu}\gamma$ by using for the first time an almost fully polarized muon source. We identified a large sample (~13000) of these decays in a total sample of 1.8x10^14 positive muon…
A new result for the transverse mu^+ polarization, P_T, in the decay K^+ --> pi^0 mu^+ nu has been obtained in the KEK E246 experiment. Combined with our earlier result, P_T = (-1.12 +- 2.17(stat) +- 0.90(syst))x10^{-3} and Im(\xi) = (-0.28…