Study of KK coupled decays and K-Be interactions with the CMD-2 detector at VEPP-2M collider

Abstract

The integrated luminosity ≈ 4000nb −1 of around φ meson mass (5.0× 10 6 of φ's) has been collected with the CMD-2 detector at the VEPP-2M collider. A latest analysis of the K S K L coupled decays based on 30% of available data is presented in this paper.The K S K L pairs from φ decays were reconstructed in the drift chamber when both kaons decayed into two charged particles. From a sample of 1423 coupled decays a selection of candidates to the CP violating K L → π + π − decay was performed. CP violating decays were not identified because of the domination of events with a K L regenerating at the Be beam pipe into K S and a background from K L semileptonic decays.The regeneration cross section of 110 MeV/c K L 's was found to be σ Be reg = 53 ± 17 mb in agreement with theoretical expectations. The angular distribution of K S 's after regeneration and the total cross section of K L for Be have been measured.