Abstract :
Changes in shell closures through nucleon transfer and nucleon knockout reactions as spectroscopic probes are discussed. The intruder s-orbital in the ground and excited states of 12Be is studied through the 11Be(d,p) reaction. Signature of the View the MathML source long-lived state having an s-wave halo-like structure in 12Be is observed. One-neutron knockout from 24O shows a large spectroscopic factor for the s-orbital thereby establishing it as a new doubly magic nucleus at the drip-line.
