2004/04/16 by Samuel Friot, David Greynat, Eduardo de Rafael +1 · 92 citations
Physics and Astronomy · #Amplitude #Chiral perturbation theory #Constructive #High-Energy Particle Collisions Research #Invariant (physics) #Invariant mass #Mass spectrometry #Mass spectrum #Mathematical physics #Particle physics #Particle physics theoretical and experimental studies #Perturbation theory (quantum mechanics) #Physics #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #Quantum mechanics #hep-ph
paper · pdf · doi:10.1016/j.physletb.2004.05.069
published in Physics Letters B 595(1-4), 301-308 (Elsevier BV)
arxiv created 2004/04/16 · openalex publication_date 2004/06/24 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We present an updated discussion of K→πl̄l decays in a combined framework of chiral perturbation theory and large-Nc QCD, which assumes the dominance of a minimal narrow resonance structure in the invariant mass dependence of the l̄l pair. The proposed picture reproduces very well, both the experimental K+→π+e+e− decay rate and the invariant e+e− mass spectrum. The predicted Br(KS→π0e+e−) is, within errors, consistent with the recently reported result from the NA48 Collaboration. Predictions for the K→πμ+μ− modes are also obtained. We find that the resulting interference between the direct and indirect CP-violation amplitudes in KL→π0e+e− is constructive.