Charge-symmetry-breaking three-nucleon forces

Leading-order three-nucleon forces that violate isospin symmetry are calculated in heavy-baryon chiral perturbation theory. The effect of the charge-symmetry-breaking three-nucleon force is investigated in the trinucleon systems using Faddeev calculations. We find that the contribution of this force to the ${}^3\mathrm{He}-{}^3\mathrm{H}$ binding-energy difference is given by $\Delta E_{3\mathrm{NF}}^{\mathrm{CSB}}\approx 5$ keV.