2006/11/30 by L. Roca, Atsushi Hosaka, A. Hosaka +1
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.1016/j.physletb.2007.10.035
published as Phys.Lett.B658:17-26,2007 · 16 pages, 4 figurs Added extra discussion
arxiv created 2007/09/25 · openalex publication_date 2007/10/26 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/01
A previous model where the low-lying axial-vector mesons are dynamically generated, implementing unitarity in coupled channels in the vector–pseudoscalar (VP) meson interaction, is applied to evaluate the decay widths of the a1(1260) and b1(1235) axial-vector mesons into πγ. Unlike the case of the a1, the b1 radiative decay is systematically underestimated at tree level. In this work we evaluate for the first time the loop contribution coming from an initial VP vertex. Despite the large superficial divergence of the loops, the convergence of the relevant loops can be established by using arguments of gauge invariance. The partial decay widths obtained agree with the experimental values within uncertainties, and we show that the loop contribution is crucial in the b1 case and also important for the a1 case.