Wang, F (reprint author), Zhengzhou Univ, Dept Phys & Engn, Zhengzhou 450001, Peoples R China.
[Wang, Fei] Zhengzhou Univ, Dept Phys & Engn, Zhengzhou 450001, Peoples R China
; [Wang, Wenyu
; Zhou, Sihong] Beijing Univ Technol, Inst Theoret Phys, Coll Appl Sci, Beijing 100124, Peoples R China
; [Yang, Jin Min] Acad Sinica, Inst Theoret Phys, State Key Lab Theoret Phys, Beijing 100190, Peoples R China
In this work we show that the general singlet extension of the minimal supersymmetric standard model (MSSM) can naturally provide a self-interacting singlino dark matter to solve the small cosmological scale anomalies (a large Sommerfeld enhancement factor can also be obtained). However, we find that the NMSSM (the singlet extension of the MSSM with Z(3) symmetry) cannot achieve this due to the restricted parameter space. In our analysis we introduce the concept of symmetric and antisymmetric viscosity cross sections to deal with the nonrelativistic Majorana-fermion dark matter scattering.