https://doi.org/10.1140/epjc/s2005-02365-y
Theoretical Physics
Analysis of 
decay mode with supersymmetry
1
Physics Department, National Tsing Hua University, Hsinchu 300, Taiwan
2
University of Hyderabad, School of Physics, Hyderabad 500 046, India
Motivated by the recent measurement of a low longitudinal polarization fraction in the decay mode , which appears not to be in agreement with the standard model expectation, we analyze this mode in the minimal supersymmetric standard model with the mass insertion approximation. Within the standard model, with the factorization approximation, the longitudinal polarization is expected to be 
. We find that this anomaly can be explained in the minimal supersymmetric standard model with either the LR or the RL mass insertion approximation.
PACS. 13.25.Hw, 11.30.Er, 12.60.Jv
© Springer-Verlag, 2005
