S. Pislak et al., New measurement of Ke4(+) decay and the s-wave pi pi-scattering length a(0)(0) - art. no. 221801, PHYS REV L, 8722(22), 2001, pp. 1801
A sample of 4 x 10(5) events from the decay K+ --> pi (+) pi (-) e(+)nu (e)
(K-e4) has been collected in experiment E865 at the Brookhaven Alternating
Gradient Synchrotron. The analysis of these data yields new measurements o
f the K-e4 branching ratio [(4.11 +/- 0.01 +/- 0.11) x 10(-5)], the s-wave
pi pi scattering length [a(0)(0) = 0.216 +/- 0.013(stat) +/- 0.004(syst) +/
- 0.005(theor)], and the form factors F, G, and H of the hadronic current a
nd their dependence on the invariant pi pi mass.