2010/05/31 by Philipp Gubler, P. Gubler, M. Oka +1 · 1 citation
Physics and Astronomy · #A priori and a posteriori #Ansatz #Entropy (arrow of time) #Euclidean geometry #High-Energy Particle Collisions Research #Operator (biology) #Operator product expansion #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #Sum rule in quantum mechanics #hep-ph #nucl-th
paper · pdf · doi:10.1143/ptp.124.995
published as Prog.Theor.Phys.124:995-1018,2010 · 24 pages, 12 figures, 2 tables, extended discussion on the role of the default model, several typos corrected, published version
openalex publication_date 2010/12/01 · arxiv created 2011/01/10 · arxiv updated 2015/03/16 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
QCD sum rules are analyzed with the help of the Maximum Entropy Method. We develop a new technique based on the Bayesion inference theory, which allows us to directly obtain the spectral function of a given correlator from the results of the operator product expansion given in the deep euclidean 4-momentum region. The most important advantage of this approach is that one does not have to make any a priori assumptions about the functional form of the spectral function, such as the “pole + continuum” ansatz that has been widely used in QCD sum rule studies, but only needs to specify the asymptotic values of the spectral function at high and low energies as an input. As a first test of the applicability of this method, we have analyzed the sum rules of the ρ-meson, a case where the sum rules are known to work well. Our results show a clear peak structure in the region of the experimental mass of the ρ-meson. We thus demonstrate that the Maximum Entropy Method is successfully applied and that it is an efficient tool in the analysis of QCD sum rules.