New Result on K+→π+νν¯ from the NA62 Experiment. (April 2020)

• Record Type: Journal Article
• Authors: Ruggiero, G
• Is Part Of: Journal of physics. Volume 1526(2020)
• Publication Date: 2020-04
• Subjects: Physics -- Congresses; 530.5
• DOI: 10.1088/1742-6596/1526/1/012003
• Languages: English
• ISSNs: 1742-6588

Abstract

Abstract: The NA62 experiment at the CERN SPS is designed to measure the branching ratio of the K + → π + ν ν ¯ with a decay-in-flight technique and took data in 2016–2018. The statistics collected in 2017 allows NA62 to achieve the best up–to–date single event sensitivity for K + → π + ν ν ¯ corresponding to more than 2 Standard Model K + → π + ν ν ¯ expected events. The analysis of the 2017 data has revealed 2 candidate K + → π + ν ν ¯ events, while 1.5 background were expected. Together with the candidate found on the 2016 data, this result leads to 1.85 × 10 −10 as preliminary upper limit at 90% C.L. on the branching ratio of the K + → π + ν ν ¯ decay. The 2017 data also allow NA62 to achieve the best up–to–date sensitivity on the search for the π 0 → invisible decay.