Searcharxiv⌕ Search

arXiv subjects

Marcos Rigol

Publications and source records attributed to Marcos Rigol.

164 records · Page 10Linked to original sources

Modified initial state for perturbative QCD

A particular initial state for the construction of the perturbative expansion of QCD is investigated. It is formed as a coherent superposition of zero momentum gluon pairs and shows Lorentz as well as global SU(3) symmetries. It follows that the gluon and ghost propagators determined by it, coincides with the ones used in an alternative of the usual perturbation theory proposed in a previous work. Therefore, the ability of such a procedure of producing a finite gluon condensation parameter already in the first orders of perturbation theory is naturally explained. It also follows that this state satisfies the physicality condition of the BRST procedure in its Kugo and Ojima formulation. The BRST quantization is done for the value alpha=1 of the gauge parameter where the procedure is greatly simplified. Therefore, after assuming that the adiabatic connection of the interaction does not take out the state from the interacting physical space, the predictions of the perturbation expansion, at the value alpha=1, for the physical quantities should have meaning. The validity of this conclusion solves the gauge dependence indeterminacy remained in the proposed perturbation expansion.

hep-th↗

Baryonic resonances mass spectrum from a modified perturbative QCD

A recently proposed modified perturbation expansion for QCD is employed to evaluate the quark self-energies. Results of the order of 1/3 of the nucleon mass are obtained for the effective masses of the up and down quarks in a first approximation. Also, the predicted flavor dependence of the calculated quarks masses turns out to be the appropriate to well reproduce the spectrum of the ground states within the various groups of hadronic resonances through the simple addition of the evaluated constituent quark masses. The results suggests to conjecture that the modified expansion, after also introducing quark condensates in a same token as the gluonic ones, would be able to furnish a natural explanation of the mass spectrum of the three generations of fundamental fermions.

hep-ph↗