학술논문
Measurement of the $K_S \to \pi e \nu$ branching fraction with the KLOE experiment
Document Type
Working Paper
Author
Babusci, D.; Berlowski, M.; Bloise, C.; Bossi, F.; Branchini, P.; Cao, B.; Ceradini, F.; Ciambrone, P.; Curciarello, F.; Czerwiński, E.; D'Agostini, G.; D'Amico, R.; Danè, E.; De Leo, V.; De Lucia, E.; De Santis, A.; De Simone, P.; Di Cicco, A.; Di Domenico, A.; Diociaiuti, E.; Domenici, D.; D'Uffizi, A.; Fantini, G.; Gajos, A.; Gamrat, S.; Gauzzi, P.; Giovannella, S.; Graziani, E.; Kang, X.; Kupsc, A.; Mandaglio, G.; Martini, M.; Miscetti, S.; Moskal, P.; Passeri, A.; del Rio, E. Perez; Schioppa, M.; Selce, A.; Silarski, M.; Sirghi, F.; Solodov, E. P.; Wiślicki, W.; Wolke, M.
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Subject
Language
Abstract
The branching fraction for the decay $K_S \to \pi e \nu$ has been measured with a sample of 300 million $K_S$ mesons produced in $\phi \to K_L K_S$ decays recorded by the KLOE experiment at the DA$\Phi$NE $e^+e^-$ collider. Signal decays are selected by a boosted decision tree built with kinematic variables and time-of-flight measurements. Data control samples of $K_L \to \pi e \nu$ decays are used to evaluate signal selection efficiencies. A fit to the reconstructed electron mass distribution finds 49647$\pm$316 signal events. Normalising to the $K_S \to \pi^+\pi^-$ decay events the result for the branching fraction is $\mathcal{B}(K_S \to \pi e \nu) = (7.211 \pm 0.046_{\rm stat} \pm 0.052_{\rm syst}) \times10^{-4}$. The combination with our previous measurement gives $\mathcal{B}(K_S \to \pi e \nu) = (7.153 \pm 0.037_{\rm stat} \pm 0.043_{\rm syst}) \times10^{-4}$. From this value we derive $f_+(0)|V_{us}| = 0.2170 \pm 0.009$.
Comment: arXiv admin note: substantial text overlap with arXiv:1912.05990
Comment: arXiv admin note: substantial text overlap with arXiv:1912.05990