The NA48/2 experiment at CERN collected two data samples with minimum bias trigger conditions in 2003 and 2004. A measurement of the rate and dynamic properties of the rare decay K ± → π ±γγ from these data sets based on 149 decay candidates with an estimated background of 15.5 ± 0.7 events is reported. The model-independent branching ratio in the kinematic range z=(mγγ/mK)2>0.2 is measured to be BMI(z>0.2)=(0.877±0.089)×10-6, and the branching ratio in the full kinematic range assuming a particular Chiral Perturbation Theory description to be B(Kπγγ)=(0.910±0.075)×10-6.
|Original language||English (US)|
|Number of pages||8|
|Journal||Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics|
|State||Published - Mar 7 2014|
ASJC Scopus subject areas
- Nuclear and High Energy Physics