First thought on a high-intensity KS experiment

Abstract

The K → µµ decays have recently been identified as another golden kaon physics mode along-side the rare processes. These golden modes provide precision tests of the Standard Model with very high sensitivity to New Physics. The presented study is exploring the possibility to address the KL − KS → μ + μ − interference experimentally and outlines the challenges associated with such an ambitious project for the far future. A next-generation experiment at the intensity frontier is required that should be capable of collecting a large sample of \U0001d4aa(1014 − 1015 ) KL and KS decays. Challenges related to the beamline design and detector technology need to be overcome if we want to address this mode experimentally. A significant background suppression of KS → π + π − and radiative KL → μ + μ − γ decays is imperative for a few % measurement, which would require excellent kinematic resolution and efficient photon detection. The first attempt at a possible experimental setup to measure this effect is presented. Last but not least, a huge number of neutral particles produced offers the possibility to study a plethora of other rare KL , KS decays as well as hyperon decays enhancing the physics motivation for such an initiative.