PoS - Proceedings of Science
Volume 414 - 41st International Conference on High Energy physics (ICHEP2022) - Quark and Lepton Flavour Physics
A new $K_S \to \pi e \nu$ branching fraction measurement from KLOE-2
A. Passeri
Full text: pdf
Pre-published on: November 30, 2022
Published on:
Abstract
A new measurement of the branching fraction for the decay $K_S \to \pi e \nu$ is presented, based on a sample of 300 million $K_S$ mesons recorded by the KLOE experiment at the DA$\Phi$NE $e^+e^-$ collider. A two-step signal selection strategy is used, exploiting first kinematic variables and then time-of-flight measurements. Data control samples of $K_L \to \pi e \nu$ decays are used to evaluate signal selection efficiencies. Normalizing the selected sample to the $K_S \to \pi^+ \pi^-$ decay events the result for the branching fraction is $B(K_S \to \pi e \nu) = (7.211 \pm 0.046_{stat} \pm 0.052_{syst}) × 10^{−4}$. The combination with our previous measurement gives $B(K_S\to \pi e \nu) = (7.153 \pm 0.037_{stat} \pm 0.043_{syst} ) x 10^{-4} = (7.153 \pm 0.057) x 10^{-4}$. From this value we derive $f_+ (0)|V_{us} |=0.2170 \pm 0.0009$.
DOI: https://doi.org/10.22323/1.414.0710
How to cite

Metadata are provided both in "article" format (very similar to INSPIRE) as this helps creating very compact bibliographies which can be beneficial to authors and readers, and in "proceeding" format which is more detailed and complete.

Open Access
Creative Commons LicenseCopyright owned by the author(s) under the term of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.