Measurement of with NA48/2 at CERN

10th International Conference on Kaon Physics

Khoriauli, Gia^1

Johannes Gutenberg University of Mainz, Staudingerweg 7, Mainz

55128, Germany^1

关键词: Accurate measurement;    Branching ratio;    Chiral perturbation theory;    Electron-positron pairs;    Next-to-leading orders;    Phase space regions;    Radiative decay;    Theoretical values;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/800/1/012035/pdf
DOI  :  10.1088/1742-6596/800/1/012035

来源: IOP

【 摘 要 】

The exclusive branching ratio of the radiative decay K± → μ ± v μe+e-is measured using data collected by the NA48/2 experiment at CERN in 2003-2004. The measurement is performed in the phase-space region of the mass of the electron-positron pair, me+e-≥ 140 MeV=c2. This is the most accurate measurement of the exclusive BR(± → μ ± v μe+e-). The result, BR(K± → μ ± v μe+e-/me+e-≥ 140 MeV/c2) = (7:81 ± 0:23) × 10-8is compatible with the theoretical value, 8:51 7times; 10-8, calculated using the Chiral Perturbation Theory framework at next-to-leading order.