Status of the B -> pi K puzzle and its relation to B_s -> phi pi and B_s   -> phi rho decays
  Some discrepancies between theory and experiment in the B -> pi K decays suggest the possibility of a new physics contribution with the structure of an electroweak penguin amplitude. If such a scenario is realised in nature, the branching ratios of the decays B_s -> phi pi and B_s -> phi rho can be enhanced by about one order of magnitude. We review and update the current status of the B -> pi K puzzle and its implications for the decays B_s -> phi pi and B_s -> phi rho. 
Lars Hofer and Leonardo Vernazza
hep-ph