0000000000052124
AUTHOR
Masafumi Koike
showing 5 related works from this author
Big-bang nucleosynthesis and the relic abundance of dark matter in a stau-neutralino coannihilation scenario
2008
A scenario of the Big-Bang Nucleosynthesis is analyzed within the Minimal Supersymmetric Standard Model which is consistent with a stau-neutralino coannihilation scenario to explain the relic abundance of dark matter. We find that we can account for the possible descrepancy of the abundance of $\mathrm{^{7}Li}$ between the observation and the prediction of the Big-Bang Nucleosynthesis by taking the mass of the neutralino as $300 \mathrm{GeV}$ and the mass difference between the stau and the neutralino as $(100 -- 120) MeV$. We can therefore simultaneously explain the abundance of the dark matter and that of $\mathrm{^{7}Li}$ by these values of parameters. The lifetime of staus in this scena…
Stau relic density at the big-bang nucleosynthesis era in the coannihilation scenario and a solution to theLi7problem
2010
The work of K. K. was supported in part by PPARC Grant No. PP/D000394/1, EU Grant No. MRTN-CT-2006-035863, the European Union through the Marie Curie Research and Training Network "UniverseNet," MRTN-CT-2006-035863, and Grant-in-Aid for Scientific research from the Ministry of Education, Science, Sports, and Culture, Japan (No. 18071001). The work of M. K. was supported in part by the Grant-in-Aid for the Ministry of Education, Culture, Sports, Science, and Technology, Government of Japan (No. 22740140). The work of J. S. was supported in part by the Grant-in-Aid for the Ministry of Education, Culture, Sports, Science, and Technology, Government of Japan (Nos. 20025001, 20039001, and 205402…
Model building by coset space dimensional reduction in ten dimensions with direct product gauge symmetry
2009
14 pages.-- ISI article identifier:000264762400083.-- ArXiv pre-print avaible at:http://arxiv.org/abs/0812.0910
GAUGE-HIGGS UNIFICATION MODELS WITH COSET SPACE DIMENSIONAL REDUCTION SCHEME
2009
We investigate the gauge-Higgs unification models within the scheme of the coset space dimensional reduction, beginning with two types of set up; fourteen-dimensional gauge theory with simple gauge groups and ten-dimensional gauge theory with direct product gauge groups. We found some phenomenologically acceptable models through an exhaustive search for the candidates of the coset spaces, the gauge group in higher dimension, and fermion representation.
Cosmological promising parameters of stau in the minimal supersymmetric standard model
2009
We find that we can account for the possible descrepancy of the primordial abundance of 7 Li between the observation and the prediction of the Big-Bang Nucleosynthesis in a scenario of the Big-Bang Nucleosynthesis with the Minimal Supersymmetric Standard Model. This scenario is consistent with a stau-neutralino coannihilation scenario to explain the relic abundance of dark matter. The solution to the discrepancy is given by taking the values of parameters; the mass of the neutralino as 300 GeV and the mass difference between the stau and the neutralino as (100 – 120) MeV.