NuFact 2021: The 22nd International Workshop on Neutrinos from Accelerators

Measurement of the very rare K+→π+νν¯ decay at the NA62 experiment at CERN

Not scheduled

20m

Online

Poster Poster session NB: do not use Safari; use Firefox, Chrome or Edge

Speaker

Renato Fiorenza (Universita e sezione INFN di Napoli (IT))

Description

The NA62 experiment reports the branching ratio measurement BR(K+→π+νν) at 68% CL, based on the observation of 20 signal candidates with an expected background of 7.0 events from the total data sample collected at the CERN SPS during 2016-2018. This provides evidence for the very rare K+→π+νν decay, observed with a significance of 3.4σ. The experiment achieves a single event sensitivity of (0.839±0.054)×10−11, corresponding to 10.0 events assuming the Standard Model branching ratio of (8.4±1.0)×10−11. The result represents the most accurate measurement achieved so far of this ultra-rare decay. Future prospects and plans for data taking from 2021 will also be presented.