Kinematics
Reconstructing the incoming kaon and outgoing charged track constrains the invisible part of the event through missing momentum.
CERN · Super Proton Synchrotron
NA62
NA62 is a fixed-target experiment built to study extremely rare charged-kaon decays. Its precision measurements test the Standard Model and probe for indirect signs of new physics.
- SPS
- high-energy proton beam
- Fixed target
- kaon-rich secondary beam
- Rare decays
- precision Standard Model tests
Scientific purpose
Learning from an exceptionally rare decay
A central goal of NA62 is to measure how often a positively charged kaon decays into a positively charged pion and a neutrino–antineutrino pair. The Standard Model predicts this process very precisely, but it happens extraordinarily rarely. A measured rate that differs from the prediction could point to particles or interactions not yet included in the theory.
Measurement strategy
How a rare signal is isolated
Particle identification
Cherenkov detectors and complementary subsystems distinguish kaons, pions, muons, electrons, and photons in a high-rate environment.
Background rejection
Redundant measurements and broad veto coverage exclude ordinary kaon decays that could otherwise imitate the rare signal.