Direct CP violation in charm at Belle

Using the full data sample collected with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider, we have searched for CP violation of charmed mesons in $D^+\rightarrow K^0_S\pi^+$ and $D^0\rightarrow h^+h^-$ decays, where $h$ denotes $K$ and $\pi$. We observe evidence for CP violation in $D^+\rightarrow K^0_S\pi^+$ decay with 3.2 standard deviations away from zero, $(-0.363\pm0.094\pm0.067)$, while the asymmetry is consistent with the expected CP violation due to the neutral kaon in the final state. No evidence for CP violation in $D^0\rightarrow h^+h^-$ is observed with $A^{KK}_{CP}=(-0.32\pm0.21\pm0.09)$ and $A^{\pi\pi}_{CP}=(+0.55\pm0.36\pm0.09)$. The CP asymmetry difference between $D^0\rightarrow K^+K^-$ and $D^0\rightarrow\pi^+\pi^-$ decays is also measured with $\Delta A^{hh}_{CP}=(-0.87\pm0.41\pm0.06)$, which is 2.1 standard deviations away from zero and supports recent LHCb and CDF measurements.Comment: Proceedings of the 36th International Conference on High Energy Physics - ICHEP 2012; July 4-11 2012; Melbourne, Australi

First Axion Dark Matter Search with Toroidal Geometry

We report the first axion dark matter search with toroidal geometry. Exclusion limits of the axion-photon coupling $g_{a\gamma\gamma}$ over the axion mass range from 24.7 to 29.1 $\mu$eV at the 95\% confidence level are set through this pioneering search. Prospects for axion dark matter searches with larger scale toroidal geometry are also given.Comment: Contributed to the 13th Patras Workshop on Axions, WIMPs and WISPs, Thessaloniki, May 15 to 19, 201

A numerical study of diffusive shock acceleration of cosmic rays in supernova shocks

The evolution of the energy spectrum of cosmic rays accelerated by the first order Fermi mechanism, by a supernova remnant shock wave, including adiabatic deceleration effects behind the front, is carried out by means of a time-dependent numerical code. The calculations apply to the adiabatic stage (or Sedov stage) of the supernova explosion, and the energetic particle spectrum is calculated in the test particle limit (i.e., the back reaction of the cosmic rays on the flow is not included). The particles are injected mono-energetically at the shock. The radial distribution, The radial distribution, and the spectrum of the accelerated and decelerated particles is shown