The single particle (s.p.) potential felt by nucleons in nuclear medium is a basic ingredient of the transport models (such as BUU and QMD) for HIC.Nucleon effective mass stems from the non-local nature of the s.p.potential felt by a nucleon propagating in nuclear medium and The single particle (sp) potential felt by nucleons in nuclear medium is a basic ingredient of the transport models (such as BUU and QMD) for HIC. Nucleon effective mass stems from the non-local nature of the sppotential felt by a nucleon propagating in nuclear medium and