Measurement of the absolute branching ratio of the K+ -> pi+ pi0 (gamma)   decay with the KLOE detector
  We have measured the absolute branching ratio of the K+ -> pi+ pi0 (gamma) decay, using about 20 million tagged K+ mesons collected with the KLOE detector at DAFNE, the Frascati phi-factory. Signal counts are obtained from the fit of the distribution of the momentum of the charged decay particle in the kaon rest frame. The result, inclusive of final-state radiation, is BR(K+ -> pi+ pi0 (gamma))=0.2065+/-0.0005_{stat}+/- 0.0008_{syst}. 
F. Ambrosino, A. Antonelli, M. Antonelli, F. Archilli, C. Bacci, P.   Beltrame, G. Bencivenni, S. Bertolucci, C. Bini, C. Bl...