Allowed slepton intergenerational mixing in light of light element abundances

作者：Kohri Kazunori^*; Ohta Shingo; Sato Joe; Shimomura Takashi; Yamanaka Masato

来源：Physical Review D - Particles, Fields, Gravitation and Cosmology, 2012, 86(9): 095024.

DOI：10.1103/PhysRevD.86.095024

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, Li-7 and Li-6 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 X 10(-11) less than or similar to c(e) less than or similar to 2 x 10(-9) with solving both the Li-7 and Li-6 problems. Similarly, the ratio for smuon, c(mu), is allowed in c(mu) less than or similar to 5 X 10(-5) for mass difference between slepton and neutralino, which is smaller than muon mass, and c(mu) less than or similar to 2 X 10(-10) 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.

• 出版日期2012-11-19