2013/10/31 by Michael Altenbuchinger, M. Altenbuchinger, Li-Sheng Geng +1 · 1 citation
Physics and Astronomy · #Bethe–Salpeter equation #Boson #Bottleneck #Chiral perturbation theory #Computer science #Formalism (music) #Goldstone boson #High-Energy Particle Collisions Research #Meson #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #Quark #Theoretical physics #hep-lat #hep-ph #nucl-th
paper · pdf · doi:10.1103/physrevd.89.054008
published as Phys. Rev. D 89, 054008 (2014) · An appendix added to illustrate how the Bethe-Salpeter equation with a full-off shell potential is solved. To appear in Physical Review D
arxiv created 2014/02/21 · openalex publication_date 2014/03/06 · arxiv updated 2014/03/12 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The Bethe-Salpeter equation in unitarized chiral perturbation theory is usually solved with the so-called on-shell approximation. The underlying argument is that the off-shell effects can be absorbed by the corresponding coupling constants and physical masses, which has been corroborated by the success of unitarized chiral perturbation theory in describing a variety of physical phenomena. Such an approximation needs to be scrutinized when applied to study the light-quark mass evolution of physical observables, as routinely performed nowadays. In the present work, we propose to solve the Bethe-Salpeter equation with the full off-shell terms of the chiral potentials and apply this formalism to the description of the latest nf=2+1 lattice QCD (LQCD) data on the scattering lengths of Nambu-Goldstone bosons off D mesons. It is shown that the LQCD data can be better described in this formalism than in the widely used on-shell approximation. On the other hand, no qualitative difference between the on-shell and off-shell approaches is observed for the light-quark mass evolution of the scattering lengths, given the limited LQCD data and their relatively large uncertainties. We also show that the light-quark mass dependence of the Ds0*(2317) remains essentially the same in both approaches.