Non-Perturbative Renormalization Group Analysis of the Ohmic Quantum   Dissipation
  We analyze quantum tunneling with the Ohmic dissipation by the non-perturbative renormalization group method. We calculate the localization susceptibility to evaluate the critical dissipation for the quantum-classical transition, and find considerably larger critical dissipation compared to the previous semi-classical arguments. 
Ken-Ichi Aoki and Atsushi Horikoshi (Kanazawa University)