A low-background sample of 10 300 events has been collected for the decay mode K+ → π+e+e- by experiment E865 at the Brookhaven Alternating Gradient Synchrotron. The branching ratio is measured to be [2.94±0.05(stat)±0.13(syst)±0.05(model)]×10-7, the vector nature of this decay is firmly established, and the decay form factor f(z)=f0(1+δz)(z = M2ee/m2K) is determined to have δ = 2.14±0.13±0.15. The experiment is described and results discussed in the context of chiral perturbation theory.
|Number of pages||4|
|Journal||Physical Review Letters|
|State||Published - 1999|