High statistic measurement of the K- -> pi0 e- nu decay form-factors

• Published in: arXiv.org 2004-04
• Main Authors: Yushchenko, O P, Akimenko, S A, Britvich, G I, Datsko, K V, Filin, A P, Inyakin, A V, Konstantinov, A S, Konstantinov, V F, Korolkov, I Y, Khmelnikov, V A, Leontiev, V M, Novikov, V P, Obraztsov, V F, Polyakov, V A, Romanovsky, V I, Ronjin, V M, Shelikhov, V I, Smirnov, N E, Tchikilev, O G, Uvarov, V A, Bolotov, V N, Laptev, S V, A Yu Polyarush
• Format: Article
• Language: English
• Subjects: Couplings; Decay; Tensors
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.0404030

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).