*Article* **Probing Different Characteristics of Shell Evolution Driven by Central, Spin-Orbit, and Tensor Forces**

**Yutaka Utsuno 1,2**


**Abstract:** In this paper, the validity of the shell-evolution picture is investigated on the basis of shell-model calculations for the atomic mass number 25 - *A* - 55 neutron-rich nuclei. For this purpose, the so-called SDPF-MU interaction is used. Its central, two-body spin–orbit, and tensor forces are taken from a simple Gaussian force, the M3Y (Michigan 3-range Yukawa) interaction, and a *π* + *ρ* meson exchange force, respectively. Carrying out almost a complete survey of the predicted effective single-particle energies, it is confirmed here that the present scheme is quite effective for describing shell evolution in exotic nuclei.

**Keywords:** shell evolution; exotic nuclei; shell model; effective interaction; tensor force; spectroscopic factor; effective single-particle energy
