Kiyoshi Shiraishi

Design, construction, and initial performance of SciBar detector in K2K experiment

A new near detector for the K2K long baseline neutrino experiment, the SciBar, was constructed and started data taking to study neutrino interactions. In K2K, neutrino oscillation is studied by comparing the number of neutrino interactions and energy spectrum between near and far detectors. In order to study neutrino oscillations more precisely, it is necessary to improve the measurement of neutrino spectrum and interactions below 1 GeV, where the latest K2K results suggest maximum oscillation. For that purpose, SciBar is designed to be fully active with fine segmentation. We present the design and basic performance. All detector components have been working as expected. Also presented are the measurements of charged current interactions which are used in the latest K2K oscillation analysis

Newtonian analysis of multiscalar boson stars with large self-couplings

We study solutions for boson stars in the multi-scalar field theory with global symmetry

Analytical study of charged boson stars with large scalar self-couplings

[U(1)]^N

Integrable higher-dimensional cosmology with separable variables in an Einstein-dilaton-antisymmetric field theory

. The properties of the boson stars are investigated by the Newtonian approximation with the large coupling limit. Our purpose is to study the models bringing about exotic mass distributions which explain flat rotation curves of galaxies. We propose plausible models in which coupling matrices are associated with various graphs in graph theory.

Induced Gravity in Deconstructed Space at Finite Temperature -- Self-consistent Einstein Universe

We give good approximate analytic solutions for spherical charged boson stars in the large scalar-self-coupling limit in general relativity. We show that if the charge e and mass m of the scalar field nearly satisfy the critical relation