Study of the decay K sup + r arrow. pi. sup + e+ e minus

• Published in: Physical review letters Vol. 68:3
• Main Authors: Alliegro, C., Campagnari, C., Chaloupka, V., Cooper, P.S., Egger, J., Gordon, H.A., Hadley, N.J., Herold, W.D., Kaspar, H., Lee, A.M., Lazarus, D.M., Lubatti, H.J., Rehak, P., Zeller, M.E., Zhao, T.
• Format: Journal Article
• Language: English
• Published: United States 20-01-1992
• Subjects: 662350 - Decays of Mesons- (1992-); BOSONS; BRANCHING RATIO; DATA; DATA ANALYSIS; DECAY; ELECTRONS; ELEMENTARY PARTICLES; EXPERIMENTAL DATA; FERMIONS; HADRONS; INFORMATION; KAONS; KAONS PLUS; LEPTONS; LIMITING VALUES; MASS SPECTRA; MESONS; MONTE CARLO METHOD; NUMERICAL DATA; PARTICLE DECAY; PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; PIONS; PSEUDOSCALAR MESONS; SEMILEPTONIC DECAY; SPECTRA; STRANGE MESONS; STRANGE PARTICLES; WEAK PARTICLE DECAY
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/PhysRevLett.68.278

We present results of an experiment in which approximately 500 events of the decay {ital K}{sup +}{r arrow}{pi}{sup +}{ital e+}{ital e{minus}} were observed. We have measured the branching ratio for {ital K}{sub {pi}{ital e}{ital e}}{sup +} to be (2.75{plus minus}0.23{plus minus}0.13){times}10{sup {minus}7} assuming a vector interaction with a form factor of {lambda}=0.105{plus minus}0.035{plus minus}0.015. We have also found the branching ratio times decay probability for {ital K}{sup +}{r arrow}{pi}{sup +}{ital X0}, {ital X}{sup 0}{r arrow}{ital e}{sup +}{ital e{minus}} to be less than 1.5{times}10{sup {minus}8} (99% C.L.) over an {ital X}{sup 0} invariant mass range from 150 to 340 MeV/{ital c}{sup 2}.