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A new measurement of K+(e4) decay and the s-wave pi-pi-scattering length a00

S. Pislak·R. Appel·G. S. Atoyan·B. Bassalleck·D. R. Bergman·N. Cheung·S. Dhawan·H. Do·J. Egger·S. Eilerts·W. Herold·V. V. Issakov·H. Kaspar·D. E. Kraus·D. M. Lazarus·P. Lichard·J. Lowe·J. Lozano·H. Ma·W. Majid·A. A. Poblaguev·P. Rehak·A. Sher·J. A. Thompson·P. Truol·M. E. Zeller·BNL-E865 Collaboration
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Abstract

A sample of 400000 events from the decay K+->pi+pi-e+nu(e)(K(e4)) has been collected in experiment E865 at the Brookhaven AGS. The analysis of these data yields new measurements of the K(e4) branching ratio (4.11+-0.01+-0.11)*10**(-5)), the s-wave pi-pi scattering length a00=0.228+-0.012+-0.003, and the form factors F, G, and H of the hadronic current and their dependence on the invariant pi-pi mass.

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S. Pislak, R. Appel, G. S. Atoyan, B. Bassalleck, D. R. Bergman, N. Cheung, S. Dhawan, H. Do, J. Egger, S. Eilerts, W. Herold, V. V. Issakov, H. Kaspar, D. E. Kraus, D. M. Lazarus, P. Lichard, J. Lowe, J. Lozano, H. Ma, W. Majid, A. A. Poblaguev, P. Rehak, A. Sher, J. A. Thompson, P. Truol, M. E. Zeller, BNL-E865 Collaboration. 2001-06-19. A new measurement of K+(e4) decay and the s-wave pi-pi-scattering length a00. https://doi.org/10.1103/physrevlett.87.221801%2010.1103%2Fphysrevlett.105.019901

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