Collectivity-induced quenching of signatures for shell closures
  Mass differences are an often used as signature and measure for shell closure. Using the angular-momentum projected Generator Coordinate Method and the Skyrme interaction SLy4, we analyze the modification of mass differences due to static deformation and dynamic fluctuations around the mean-field ground state. 
M. Bender, G.F. Bertsch and P.-H. Heenen