New physics may show itself in vector portal via the kinetic mixing of the ordinary photon with the dark one. For very light dark photon its production in particle collisions occur via oscillations with the ordinary photon. We discuss probability of light dark photon production and its possible signatures at collider experiments.
We presented new technique of the measurement cross section at $e^{+}e^{-}$ collider. This approach base on study angular distribution in laboratory frame as function of energy near threshold, when center mass system has non-zero velocity. Such technique can be used at Super Charm-Tau Factory. Super Charm-Tau Factory has Crab Waist collision scheme of the interaction point. It gives the...
This work is dedicated to measurement of the strong phases difference between the Cabibbo favoured and doubly Cabibbo suppressed decays of the neutral D-meson for extraction of the D0 anti-D0 mixing parameters. Key feature of this new method is the reconstruction of the neutral kaon (D0->K0 pi0) in semileptonic final state. Using this method time-dependent decay rate of the kaon can provide us...
The large data sets a SCTF facility will produce will new opportunities for Partial-Wave Analyses (PWA) of various final states, of which we will study two example cases.
For $\tau$-events, we study the effects of the missing kinematic information due to the escaping neutrinos and their effect on the results of a PWA.
In D meson decays, how PWA can help to extract CP violating effects and...
We present a feasibility study of muon polarization measurement to extract the Michel parameter $\xi’$ in tau decays. We suggest as method using the angular distribution of electron in the rest frame of decayed in the drift chamber muon, as electron momentum correlates with muon polarization. The Monte Carlo simulation of Belle detector with parameters of SCT beams was used to generate signal...
Michel parameters (MP) determine the Lorentz structure of the charged weak interaction, they are in the list of the basic properties of every lepton. The difference of the measured MP from their Standard Model expectation will exhibit clear signature of the New Physics. Feasibility study of Michel parameters at the Super Charm-Tau factory and Belle II with polarized electron beam has been...
Recent results of high-statistics studies of the tau -> K pi nu decays at e+ e- B factories, Belle and BABAR, are reviewed. Complementary searches for CP symmetry violation in the tau -> K_S pi (>= 0 pi0) nu decays at BABAR and tau -> K_S pi nu at Belle are discussed. The new technique to search for CPV in tau -> K_S pi nu decay is proposed where the CPV phase is extracted in the unbinned...
