We compute the low-energy mass spectrum of lattice QCD in the large N_C limit. Expanding around a gauge-invariant ground state, which spontaneously breaks the discrete chiral symmetry, we derive an improved strong-coupling expansion and evaluate, for any value of N_C , the masses of the low-lying states in the unflavored meson spectrum. We then take the ’t Hooft limit by rescaling g^2N_C->g^2; the ’t Hooft limit is smooth and no arbitrary parameters are needed. We find, already at the fourth order of the strong-coupling perturbation theory, a very good agreement between the results of our lattice computation and the known continuum values.
Low Lying Meson Spectrum of Large N(c) Strongly Coupled Lattice QCD
GRIGNANI, Gianluca;SODANO, Pasquale
2003
Abstract
We compute the low-energy mass spectrum of lattice QCD in the large N_C limit. Expanding around a gauge-invariant ground state, which spontaneously breaks the discrete chiral symmetry, we derive an improved strong-coupling expansion and evaluate, for any value of N_C , the masses of the low-lying states in the unflavored meson spectrum. We then take the ’t Hooft limit by rescaling g^2N_C->g^2; the ’t Hooft limit is smooth and no arbitrary parameters are needed. We find, already at the fourth order of the strong-coupling perturbation theory, a very good agreement between the results of our lattice computation and the known continuum values.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
