Journalartikel

Jahr der Veröffentlichung: 2004

Seiten: 129-153

Zeitschrift: Few-Body Systems

Bandnummer: 35

Heftnummer: 3-4

ISSN: 0177-7963

eISSN: 1432-5411

DOI Link: https://doi.org/10.1007/s00601-004-0067-x

Verlag: Springer

Abstract: 
The effect of quark-gluon vertex dressing on the ground-state masses of the u/d-quark pseudoscalar, vector and axialvector mesons is considered with the Dyson-Schwinger equations. This extends the ladder-rainbow Bethe-Salpeter kernel to two-loops. To render the calculations feasible for this exploratory study, we employ a simple infrared dominant model for the gluon exchange that implements the vertex dressing. The resulting model, involving two distinct representations of the effective gluon exchange kernel, preserves both the axial-vector Ward-Takahashi identity and charge conjugation symmetry. Numerical results confirm that the pseudoscalar meson retains its Goldstone boson character. The vector meson mass, already at a very acceptable value at ladder level, receives only 30 MeV of attraction from this vertex dressing. For the axial-vector states, which are about 300 MeV too low in ladder approximation, the results are mixed: The 1(+-) state receives 290 MeV of repulsion, but the 1(++) state is lowered further by 30 MeV. The exotic channels 0(--) and 1(-divided by) are found to have no states below 1.5 GeV in this model.

Harvard-Zitierstil: Watson, P., Cassing, W. and Tandy, P. (2004) Bethe-Salpeter meson masses beyond ladder approximation, Few-Body Systems, 35(3-4), pp. 129-153. https://doi.org/10.1007/s00601-004-0067-x

APA-Zitierstil: Watson, P., Cassing, W., & Tandy, P. (2004). Bethe-Salpeter meson masses beyond ladder approximation. Few-Body Systems. 35(3-4), 129-153. https://doi.org/10.1007/s00601-004-0067-x