Scaling behavior in the adiabatic Dicke Model
  We analyze the quantum phase transition for a set of $N$-two level systems interacting with a bosonic mode in the adiabatic regime. Through the Born-Oppenheimer approximation, we obtain the finite-size scaling expansion for many physical observables and, in particular, for the entanglement content of the system. 
G. Liberti, F. Plastina and F. Piperno