Searches for Physics beyond the Standard Model with Kaons at NA48 and NA62 at CERN

TL;DR

This paper discusses precision measurements of kaon decay ratios at CERN's NA48 and NA62 experiments to test the Standard Model and search for signs of New Physics, including plans for rare decay measurements.

Contribution

It introduces the development and status of methods for measuring kaon decay ratios and proposes a new measurement of the ultra rare decay $K^+ o\pi^+ uar u$ at CERN.

Findings

High-precision calculation of $R_K$ within the Standard Model.

Development of experimental methods based on 2003-04 test data.

Proposal for measuring the ultra rare decay $K^+ o\pi^+ uar u$.

Abstract

The ratio $R_K = \Gamma(K^{\pm}\to e^{\pm}\nu(\gamma)) / \Gamma(K^{\pm}\to\mu^{\pm}\nu(\gamma))$ provides a powerful probe of the structure of weak interactions. It is calculated with very high precision within the Standard Model, but corrections due to the presence of New Physics could be in a few percent range. Development of NA48/NA62 method based on test data samples of 2003-04, and the status of analysis based on a dedicated 2007 run are discussed. In addition, a proposal to measure the ultra rare decay $K^+\to\pi^+\nu\bar\nu$ at the CERN SPS is presented.