Knots and Contact Geometry

We classify Legendrian torus knots and figure eight knots in the tight contact structure on the 3-sphere up to Legendrian isotopy. As a corollary to this we also obtain the classification of transversal torus knots and figure eight knots up to transversal isotopy

Three dimensional fast tracker for central drift chamber based level 1 trigger system in the Belle II experiment

The Belle II detector at the SuperKEKB accelerator has a level 1 trigger implemented in field-programmable gate arrays. Due to the high luminosity of the beam, a trigger that effectively rejects beam induced background is required. A three dimensional tracking algorithm for the level 1 trigger that uses the Belle II central drift chamber detector response is being developed to reduce the recorded beam background while having a high efficiency for physics of interest. In this paper, we describe the three dimensional track trigger that finds and fits track parameters which we developed.Comment: 4 pages, 7 figure

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

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