2005/07/28 by A. V. Nesterenko, Joannis Papavassiliou, J. Papavassiliou
Physics and Astronomy · #Dispersion relation #High-Energy Particle Collisions Research #Massless particle #Meson #Observable #Particle physics #Particle physics theoretical and experimental studies #Physics #Pion #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #Quantum electrodynamics #Quantum mechanics #hep-ph #hep-th
paper · pdf · doi:10.1016/j.nuclphysbps.2006.11.089
published as Nucl. Phys. B (Proc. Suppl.) 164 (2007) 304-307 · Talk given at 12th International QCD Conference (QCD 05), 4 - 9 July 2005, Montpellier, France; 4 pages, 1 figure
arxiv created 2005/07/28 · openalex publication_date 2007/01/19 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
A new set of functions, which form a basis of the massive nonpower expansion for physical observables, is presented in the framework of the analytic approach to QCD at the four-loop level. The effects due to the π meson mass are taken into account by employing the dispersion relation for the Adler function. The nonvanishing pion mass substantially modifies the functional expansion at low energies. Specifically, the spacelike functions are affected by the mass of the π meson in the infrared domain below few GeV, whereas the timelike functions acquire characteristic plateaulike behavior below the two-pion threshold. At the same time, all the appealing features of the massless nonpower expansion persist in the considered case of the nonvanishing pion mass.