Results on charged kaon and hyperon decays from NA48

TL;DR

This paper reports recent measurements of charged kaon and hyperon decays from the NA48 experiments at CERN, including branching ratios, form factors, and decay asymmetries, significantly improving the precision of hyperon decay data.

Contribution

It provides new precise measurements of rare charged kaon decays and hyperon decay asymmetries, enhancing the understanding of these processes compared to previous data.

Findings

Measured branching ratios and form factors for rare kaon decays.

Achieved a tenfold increase in hyperon decay data statistics.

Provided more accurate decay asymmetry measurements.

Abstract

Recent results from the NA48/1 and NA48/2 experiments at the CERN SPS are presented. NA48/2 carried out data taking in 2003 and 2004 collecting charged kaon decays: branching ratios and form factors have been measured for the rare K+- to pi+-e+e-, K+- to pi+-gammagamma and K+- to pi+-e+e-gamma decays. The NA48/1 experiment has taken data in 2002 using only the Ks beam at an increased intensity measuring neutral hyperon radiative decays. Using this data, which exceeds present statistics by about one order of magnitude, a new precise measurement of the Csi_0 decay asymmetries has been obtained.