Explicit CP Violation in the Higgs Sector of the Next-to-Minimal Supersymmetric Standard Model

We analyze explicit CP violation in the Higgs sector of the next-to-minimal supersymmetric standard model which contains an additional gauge singlet field N . It is shown that there is no mixing among scalar and pseudoscalar Higgs fields in the two Higgs doublets, and scalar-pseudoscalar mixings could exist between two Higgs doublets and the singlet N , and between N itself. CP symmetry is conserved in the extreme limits of 〈N 〉 v, 〈N 〉 v, and tanβ 1. In the region of 〈N 〉 = O(v) and tanβ = O(1), large scalarpseudoscalar mixings are realized, and this effect can reduce the lightest Higgs mass. The mass difference between no mixing and mixing case is about 10 ∼ 30 GeV. The neutron electric dipole moment in this model is consistent with the present experimental upper limit provided that squark and gaugino masses are heavy enough of O(1) TeV. E-mail: [email protected]