2010/11/22 by J. R. Batley et al., J. R. Batley, G. Kalmus +98 · 2 citations
Chemistry · Engineering · Mathematics · Physics and Astronomy · #Algorithm #Analytical Chemistry (journal) #Asymmetry #Branching fraction #Chemistry #Chromatography #Electron #Lepton #Mathematics #Nuclear physics #Parameterized complexity #Particle Accelerators and Free-Electron Lasers #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #hep-ex
paper · pdf · doi:10.1016/j.physletb.2011.01.042
published as Phys.Lett.B697:107-115,2011 · 16 pages, 7 figures
arxiv created 2010/11/22 · openalex publication_date 2011/01/27 · arxiv updated 2011/03/31 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
A sample of 3120 K^±→π^±μ+μ- decay candidates with (3.3±0.7)% background contamination has been collected by the NA48/2 experiment at the CERN SPS, allowing a detailed study of the decay properties. The branching ratio was measured to be \rm BR=(9.62±0.25)× 10-8. The form factor W(z), where z=(Mμμ/MK)2, was parameterized according to several models. In particular, the slope of the linear form factor W(z)=W0(1+δz) was measured to be δ=3.11±0.57. Upper limits of 2.9× 10-2 and 2.3× 10-2 on possible charge asymmetry and forward-backward asymmetry were established at 90% CL. An upper limit \rm BR(K^±→π^∓μ^±μ^±)<1.1× 10-9 was established at 90% CL for the rate of the lepton number violating decay.