The Electric Dipole Moment of the Muon in a Two Higgs Doublet Model

Abstract

The electric dipole moment of the muon ($d_μ$) is evaluated in a two Higgs doublet model with a softly broken discrete symmetry. The leading contributions from both one loop and two loop diagrams are considered. For $\tanβ\equiv |v_2|/|v_1|$ close to one, contributions from two loop diagrams involving the $t$ quark and the $W$ boson dominate; while for $\tanβ\agt 10$, contributions from two loop diagrams involving the $b$ quark and the $τ$ lepton are dominant. In these two regions, $d_μ\approx (m_μ/m_e) d_e$. For $8 \agt \tanβ\agt 4$, significant cancellation occurs among the contributions from two loop diagrams and the one loop contribution dominates for $\tanβ\sim 7$. For $\tanβ\agt 15$, the calculated $d_μ$ can be close to the reach of a recently proposed experiment at the Brookhaven National Laboratory.