text: πZo 
  2 
  
  ω + ωo 
  Σ′′A(ω) = 
  λnωo Re 
  (ω + ωo)2 − ∆2 ! 
  
  comes from the interaction with the resonance and 
  p 
  
  2 
  1 − 4∆ 
  x2  x 
  ωsf 
  
  K2 
  2 
  (cid:16) 
  + 
  
  E 
  
  ω + x 
  (ω + x)2 − ∆2 
  
  |  | 
  Σ′′B(ω) = −λn 
  dx Re 
  
  (cid:17) 
  K2 
  
  1 − 4∆2 
  xωsf 
  h 
  
  4∆2 
  x2  1 − 4∆2 
  x2  x 
  ωsf 
  2∆ 
  D 
  Z 
  
  p 
  (cid:1)i 
  h 
  (cid:1)i  (cid:0)  (cid:0) 
  
  comes from the interaction with the gaped continuum.  The real part of Σ is obtained by Kramers-Kr¨onig trans- 