The properties of the three-nucleon system with the dressed-bag model for $NN$ interaction. II: Coulomb and CSB effects

Coulomb and charge-symmetry breaking effects in the ${}^3$He ground state within the dressed dibaryon model developed recently for $2N$ and $3N$ forces are examined in detail. Particular attention has been paid to the Coulomb displacement energy $\mathrm{\Delta }{E}_C=E_B{(}^3\mathrm{H})-E_B{(}^3\mathrm{H}\mathrm{e})$ and rms charge radii of ${}^3$H and ${}^3$He. A new scalar $3N$ force between the third nucleon a$ dibaryon is found to be very important for a correct description of the Coulomb energy and rms charge radius in ${}^3$He. In view of the new results for $\Delta E_C$ obtained here, the role of the effects of charge symmetry breaking in the nuclear force is discussed.