B→πKpuzzle and new physics

The present $B\ensuremath{\rightarrow}\ensuremath{\pi}K$ data is studied in the context of the standard model (SM) and with new physics (NP). We confirm that the SM has difficulties explaining the $B\ensuremath{\rightarrow}\ensuremath{\pi}K$ measurements. By adopting an effective-lagrangian parametrization of NP effects, we are able to rule out several classes of NP. Our model-independent analysis shows that the $B\ensuremath{\rightarrow}\ensuremath{\pi}K$ data can be accommodated by NP in the electroweak penguin sector.