Shell gap reduction in neutron-rich N=17 nuclei

The spectroscopy of 27Ne has been investigated through the one-neutron transfer reaction 26Ne(d,p)27Ne in inverse kinematics at 9.7 MeV/nucleon. The results strongly support the existence of a low-lying negative parity state in 27Ne, which is a signature of a reduced sd-fp shell gap in the N=16 neutron-rich region, at variance with stable nuclei.