The NA62/P326 Experiment at CERN

The rare decay (K+ to pi+ nu nubar) plays a crucial role in searching for physics beyond the Standard Model. Its branching ratio can be computed with a precision much higher than any other flavour changing neutral current process involving quarks both in K and B physics. The SM predicts a branching ratio of 8.22x10^(-11). The total theoretical uncertainty is reducible down to 5\% in view of the experimental and theoretical improvements expected in the near future. For these reasons already a 10% precision measurement of the BR may give rise to a very precise test of the Standard Model. Within the Minimal Supersimmetry Model the (K+ to pi+ nu nubar) is the best observable to determine or constrain from data the size of the scalar up-type trilinear interaction terms which enter in the soft-susy symmetry breaking sector of the model. Depending on the MSSM scenario, these effects can be as large as 20-25\% on the branching ratio with respect to effects more than two times lower for other rare decays like (B to mu mu). The experiment NA62 at CERN aims to collect about 100 (K+ to pi+ nu nubar) events with 10% background in 3 years of data taking. The experimental technique and the status of the R&D will be revised.

Event resources