High statistic measurement of the K−→π0e−ν decay form-factors

Autor: S. V. Laptev, V. M. Ronjin, Alexander Inyakin, V. M. Leontiev, V. I. Romanovsky, A. Yu. Polyarush, V.A. Polyakov, A. P. Filin, G. I. Britvich, V. P. Novikov, I. Y. Korolkov, V. F. Konstantinov, S. A. Akimenko, Oleg Yushchenko, O. G. Tchikilev, N. E. Smirnov, V. N. Bolotov, V. Obraztsov, A. S. Konstantinov, V. A. Khmelnikov, K. V. Datsko, V. I. Shelikhov, V. A. Uvarov
Rok vydání: 2004
Předmět:
Zdroj: Physics Letters B. 589:111-117
ISSN: 0370-2693
DOI: 10.1016/j.physletb.2004.03.069
Popis: The decay K- -> pi0 e- nu is studied using in-flight decays detected with the ISTRA+ spectrometer. About 920K events are collected for the analysis. The lambda+ slope parameter of the decay form-factor f+(t) in the linear approximation (average slope) is measured: lambda+(lin)= 0.02774 +- 0.00047(stat) +- 0.00032(syst). The quadratic contribution to the form-factor was estimated to be lambda'+ = 0.00084 +- 0.00027(stat) +- 0.00031(syst). The linear slope, which has a meaning of df+(t)/dt|_{t=0} for this fit, is lambda+ = 0.02324 +- 0.00152(stat) +- 0.00032(syst). The limits on possible tensor and scalar couplings are derived: f_{T}/f_{+}(0)=-0.012 +- 0.021(stat) +- 0.011$(syst), f_{S}/f_{+}(0)=-0.0037^{+0.0066}_{-0.0056}(stat) +- 0.0041(syst).
Comment: 11 pages, 8 figures. Accepted by Phys.Lett. B
Databáze: OpenAIRE
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