Year: 2004
Type: article
Abstract: We study the properties of light mesons in the scalar, pseudoscalar, and vector channels within the light-front quantization, by using the (one flavor) Nambu-Jona-Lasinio model with vector interaction. After taking into account the effects of chiral symmetry breaking, we derive the bound-state equation in each channel in the large $N$ limit ($N$ is the number of colors), which means that we consider the lowest $q\overline{q}$ Fock state with the constituent quark and antiquark. By solving the bound-state equation, we simultaneously obtain a mass and a light cone (LC) wave function of the meson. While we reproduce the previous results for the scalar and pseudoscalar mesons, we find that, for a vector meson, the bound-state equations for the transverse and longitudinal polarizations look different from each other. However, eventually after imposing a cutoff which is invariant under the parity and boost transformations, one finds these two are identical, giving the same mass and the same (spin-independent) LC wave function. When the vector interaction becomes larger than a critical value, the vector state forms a bound state, whose mass decreases as the interaction becomes stronger. While the LC wave function of the pseudoscalar meson is broadly distributed in longitudinal momentum ($x$) space, that of the vector meson is squeezed around $x=1/2$.
Authors: K. Naito, S. Maedan, K. Itakura
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2016745728