Isospin dependence of the single-particle potential of the Σ hyperon in nuclear matter

The isospin dependence of the real part of the single-particle potential of a Σ hyperon in nuclear matter, V_Σ is investigated. The isospin-dependent part V₁ of V_Σ is expressed in terms of an effective ΣN interaction in nuclear matter, which depends on proton and neutron densities. With suitable approximations numerical results for V₁ are obtained for four models of the Nijmegen baryon-baryon interaction. A comparison with recent (K^-,π^±) experiments favors model F as a realistic representation of the ΣN interaction.