2014/09/30 by Zhan-Wei Liu, Manuel E. Carrillo-Serrano, A. W. Thomas +1
Physics and Astronomy · #Amplitude #Hamiltonian (control theory) #High-Energy Particle Collisions Research #Isospin #Meson #Nuclear physics #Particle physics #Particle physics theoretical and experimental studies #Physics #Pion #Quantum Chromodynamics and Particle Interactions #Quantum mechanics #Sigma #hep-ph
paper · pdf · doi:10.1103/physrevd.91.014028
published as Phys.Rev. D91 (2015) 014028 · 8 pages and 6 figures
openalex publication_date 2015/01/23 · arxiv created 2015/01/30 · arxiv updated 2015/02/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The weak decay of the kaon to two pions is studied within the model of Nambu and Jona-Lasinio. Using the standard effective weak Hamiltonian, both the decay amplitude arising from an intermediate state \ensuremathσ meson and the direct decay amplitude are calculated. The effect of final state interactions is also included. When the matching scale is chosen such that the decay amplitude with isospin I=2 is close to its experimental value, our model including the \ensuremathσ meson contributes up to 80% of the total I=0 amplitude. This supports recent suggestions that the \ensuremathσ meson should play a vital role in explaining the \mathrm\ensuremathΔI=1/2 rule in this system.