Conveners
Tuesday afternoon: LFV, Dark, Polarization
- Kiyoshi Hayasaka (Niigata University)
Rates of lepton-flavor violation in charged lepton decays are enhanced in many beyond-the-standard-model theories. The low-background samples of $e^+e^- \to \tau^+\tau^-$ events collected by Belle and Belle II allow world-leading searches for such decays with tau leptons. We present results for the decays $\tau \to \ell V^0$, where $V^0$ is a neutral vector meson, $\tau\to\ell \gamma$, and...
The discovery of neutrino oscillations provided conclusive evidence for lepton flavor violation (LFV). LFV in the neutrino sector is expected to induce charged lepton flavor violation (CLFV), although it is highly suppressed by the small neutrino masses. However, a wide variety of new physics beyond the Standard Model can lead to enhanced rates for CLFV processes within the reach of current...
The existence and unknown nature of dark matter motivate dark sector searches at accelerators. The Belle and Belle II experiments enable dark sector searches in the sub-GeV mass region. We search for lepton-flavor-violating tau decays of type $\tau \to \ell \alpha$, where $\ell = e, \mu$ and $\alpha$ is an invisible particle. We also search for the existence of a heavy neutrino in tau decays....
We present the most recent $BABAR$ searches for reactions that could simultaneously explain the presence of dark matter and the matter-antimatter asymmetry in the Universe. This scenario predicts exotic $B$-meson decays into an ordinary-matter baryon and a dark-sector anti-baryon $\psi_D$ with branching fractions accessible at the $B$ factories.
The results are based on the full data set of...
We report on a measurement of the tau lepton polarisation using leptonic and hadronic tau lepton decays in Z -> di-tau events. A sample of pp collisions corresponding to an integrated luminosity of 36.3 fb-1 at a centre of mass energy of 13 TeV is used. The analysis method using template fitting techniques will be described for different decay modes. The measured average polarisation corrected...
Belle II is considering upgrading SuperKEKB with a polarized electron beam. The introduction of beam polarization to the experiment would significantly expand the physics program of Belle II in the electroweak, dark , and lepton flavor universality sectors. For all of these future measurements a robust method of determining the average beam polarization is required to maximize the level of...
