We study the suppression of non-planar diagrams in a scalar QCD model of a meson system in 3+1 space–time dimensions due to the inclusion of the color degrees of freedom. As a prototype of the color-singlet meson, we consider a flavor-nonsinglet system consisting of a scalar-quark and a scalar-antiquark with equal masses exchanging a scalar-gluon of a different mass, which is investigated within the framework of the homogeneous Bethe–Salpeter equation. The equation is solved by using the Nakanishi representation for the manifestly covariant bound-state amplitude and its light-front projection. The resulting non-singular integral equation is solved numerically. The damping of the impact of the cross-ladder kernel on the binding energies are studied in detail. The color-suppression of the cross-ladder effects on the light-front wave function and the elastic electromagnetic form factor are also discussed. As our results show, the suppression appears significantly large for Nc=3, which supports the use of rainbow-ladder truncations in practical non-perturbative calculations within QCD.
Color-suppression of non-planar diagrams in bosonic bound states / DE ALVARENGA NOGUEIRA, JORGE HENRIQUE; Chueng-Ryong, Ji; E., Ydrefors; T., Frederico. - In: PHYSICS LETTERS. SECTION B. - ISSN 0370-2693. - 777:(2018), pp. 207-211. [10.1016/j.physletb.2017.12.032]
Color-suppression of non-planar diagrams in bosonic bound states
DE ALVARENGA NOGUEIRA, JORGE HENRIQUEPrimo
;
2018
Abstract
We study the suppression of non-planar diagrams in a scalar QCD model of a meson system in 3+1 space–time dimensions due to the inclusion of the color degrees of freedom. As a prototype of the color-singlet meson, we consider a flavor-nonsinglet system consisting of a scalar-quark and a scalar-antiquark with equal masses exchanging a scalar-gluon of a different mass, which is investigated within the framework of the homogeneous Bethe–Salpeter equation. The equation is solved by using the Nakanishi representation for the manifestly covariant bound-state amplitude and its light-front projection. The resulting non-singular integral equation is solved numerically. The damping of the impact of the cross-ladder kernel on the binding energies are studied in detail. The color-suppression of the cross-ladder effects on the light-front wave function and the elastic electromagnetic form factor are also discussed. As our results show, the suppression appears significantly large for Nc=3, which supports the use of rainbow-ladder truncations in practical non-perturbative calculations within QCD.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
