Allowed slepton intergenerational mixing in light of light element abundances

We studied allowed region on the intergenerational mixing parameters of sleptons from a viewpoint of big-bang nucleosynthesis in a slepton-neutralino coannihilation scenario. In this scenario, $^7$Li and $^6$Li problems can be solved by considering exotic reactions caused by bound-state effects with a long-lived slepton. Light element abundances are calculated as functions of the relic density and lifetime of the slepton which considerably depend on the intergenerational mixing parameters. Compared with observational light element abundances, we obtain allowed regions on the intergenerational mixing. Ratio of selectron component to stau component, $c_e$, is allowed in $2\times 10^{-11} \lesssim c_e \lesssim 2\times 10^{-9}$ with solving both the $^7$Li and $^6$Li problems. Similarly, the ratio for smuon, $c_{\mu}$, is allowed in $10^{-7} \lesssim c_{\mu} \lesssim 5\times 10^{-5}$ for mass difference between slepton and neutralino, which is smaller than muon mass, and $$ for the mass difference in range between muon mass and 125 MeV. We also discuss collider signatures of the slepton decays. We find characteristic double peaks in momentum distribution of event number of the slepton decays with allowed mixing parameters. Discoveries of the double peaks at future collider experiments should confirm our scenario.Comment: 10 pages, 6 figure

Running Test of VVVF Inverter Type Railcar Using Lithium Ion Battery

Lithium ion battery was applied to the running of VVVF inverter type railcar. 15kWh of Mn type lithium ion battery was used. The relation between running time and voltage, current and integrating watt was investigated. The running test was also carried out using VVVF inverter type railcar to investigate charge performance due to regenerative energy. Lithium ion battery module was quickly charged for three times at rate of 4.68C by regenerative braking system. It was estimated that the effect of energy saving was about 22% by the charge of lithium ion battery from regenerative energy

Application of rubber artificial muscle manipulator as a rehabilitation robot

The application of robot to rehabilitation has become a matter of great concern. This study deals with an exercise for restoration of function being one of important rehabilitation tasks. An exercise of single joint has already been achieved with some automatically controlled machines. Now, the multijoint exercise becomes desirable, which requires the exercise robot with multi ple degrees of freedom to generate more realistic motion pattern. This kind of robot has to be absolutely safe for humans. A pneumatic calculator may be so effective for such a robot because of the flexibility from air compressibility that a rubber artificial muscle manipulator pneumatically driven is applied to construct the exercise robot with two degrees of freedom. Also an impedance control strategy is employed to realize various exercise motion modes. Further, an identification method of the recovery condition is proposed to execute the effective rehabilitation. Some experiments show the availability of proposed rehabilitation robot system </p

Long life stau in the minimal supersymmetric standard model

We study the stau lifetime in a scenario with the LSP taken to be a neutralino and the NLSP being a stau, based on the minimal supersymmetric Standard Model. The mass difference between the LSP and NLSP, $\delta m$, must satisfy $\delta m/m_{\tilde{\chi}} \sim$ a few % or less for coannihilation to occur, where $m_{\tilde{\chi}}$ is the neutralino mass. We calculate the stau lifetime from the decay modes $\tilde{\tau}\to \tilde{\chi}\tau$, $\tilde{\chi}\nu_\tau\pi$, and $\tilde{\chi}\nu_\tau\mu(e)\nu_{\mu(e)}$ and discuss its dependence on various parameters. We find that the lifetime is in the range $10^{-22}$--$10^{16}$ sec for $10^{-2} \le \delta m \le 10$ GeV. We also discuss the connection with lepton flavor violation if there is mixing between sleptons.Comment: 15 pages, 5 figure