The hyperon mean free paths in the relativistic mean field

The Lambda- and Xi(-)-hyperon mean free paths in finite nuclei are firstly calculated in the relativistic mean-field theory. The real optical potentials are derived from the RMF approach, while the imaginary parts are obtained from the assumptions: U-S(IY) = alpha(sigma Y) . U-S(IN) and U-V(IY) = alpha(omega Y) . U-V(IN). With these assumptions, the depth of the imaginary potential for Xi(-) is W-Xi similar or equal to -3.5 MeV, and for Lambda is W-Lambda similar or equal to -7 MeV at low incident energy. We find that the hyperon MFP decreases with the increment of the incident energies of the hyperon (from 200 MeV to 800 MeV); and in the nuclear interior, the MFP is about 2-3 fm for Lambda, and about 4-8 fm for Xi(-), depending on the incident energy of the hyperon.