New measurement of the K+→π+νν¯ branching ratio at NA62
Abstract
A new measurement of the K + → π + ν ν ¯ decay by the NA62 experiment at the CERN SPS is presented, using data collected in 2021 and 2022 at higher instantaneous beam intensity with respect to the 2016–2018 data taking. Combining NA62 data collected in 2016–2022, 51 signal candidates were observed with an expected background of 18 − 2 + 3 events. The resulting branching ratio B ( K + → π + ν ν ¯ ) = ( 13 . 0 − 3.0 + 3.3 ) × 10 − 11 is the smallest one measured with a signal significance above 5 σ .
Fields of Study & Subjects
Particle physics theoretical and experimental studies
Particle Detector Development and Performance
Neutrino Physics Research
Publication details
- Journal / source
- Journal of subatomic particles and cosmology.
- Volume
- 5
- Pages
- 100287–100287
- Publication date
- 14 January 2026
- Language
- EN