Longitudinal polarization in K_L→μ⁺μ^- in MSSM with large tanβ

Abstract

A complete experiment on decay K_L→l⁺l^- will not only consist of measurement of the decay rates but also lepton polarization etc. These additional observations will yield tests of CP invariance in these decays. In K_L and K_S decays, the e mode is slower than the μ mode by roughly (m_e/m_μ)² [4]. As well discussed in literature [5] the Standard Model contribution to the lepton polarization is of order 2×~10^-3. We show that in MSSM with large tanβ and light higgs masses (~2M_W), the longitudinal lepton polarization in K_L→μ⁺μ^- can be enhanced to a higher value, of about 10^-2.