Toshikazu Kuniya

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The Belle detector was designed and constructed to carry out quantitative studies of rare B-meson decay modes with very small branching fractions using an asymmetric e þ e À collider operating at the U(4S) resonance, the KEK-B-factory. Such studies require data samples containing B10 7 B-meson decays. The Belle detector is configured around a 1:5 T(More)
We present a measurement of the standard model CP violation parameter sin2 phi(1) based on a 29.1 fb(-1) data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. One neutral B meson is fully reconstructed as a J/psi K(S), psi(2S)K(S), chi(c1)K(S), eta(c)K(S), J/psi K(L), or J/psi K(*0) decay(More)
In this paper, we investigate the dynamics of a five-dimensional virus model with immune responses and an intracellular delay which describes the interactions of the HIV virus, CD4 cells and CTLs within host, which is an improvement of some existing models by incorporating (i) two distributed kernels reflecting the variance of time for virus to invade into(More)
In this paper, by extending well-known Lyapunov function techniques, we establish sufficient conditions for the global stability of an endemic equilibrium of a multi-group SIRS epidemic model with varying population sizes which has cross patch infection between different groups. Our proof no longer needs such a grouping technique by graph theory commonly(More)
>IJH=?J In this paper, we study the long-time behavior of a nonautonomous SEIRS epidemic model. We obtain new sucient conditions for the permanence (uniform persistence) and extinction of infectious population of the model. By numerical examples we show that there are cases such that our results improve the previous results obtained in [T. We discuss a(More)
We have studied the performance of a CCD tracker using minimum ionizing particles (MIP's) from KEK PS beam line. The detector consists of three layers of CCD sensors manufactured by Hamamatsu Photonics, which suppress the dark current at surface by one order of magnitude compared with that of the conventional ones. We have observed MIP's can be detected(More)
We have developed a Monte-Carlo simulation code for an aerogelČerenkov Counter which is operated under a strong magnetic field such as 1.5T. This code consists of two parts: photon transportation inside aerogel tiles, and one-dimensional amplification in a fine-mesh photomultiplier tube. It simulates the output photo-electron yields as accurately as 5% with(More)
In this paper, applying Lyapunov functional approach, we establish sufficient conditions under which each equilibrium is globally asymptotically stable for a class of multi-group SIR epidemic models. The incidence rate is given by nonlinear incidence rates and distributed delays incorporating not only an exchange of individuals between patches through(More)