Ground State Meson Spectrum in a Relativistic Model with Instanton Induced Interaction

Abstract

The mass spectrum of the S-wave mesons is considered in the frame work of relativistic harmonic model (RHM). The full Hamiltonian used in the investigation has the Lorentz scalar plus a vector harmonic-oscillator potential, the confined-one-gluon-exchange potential (COGEP) and the instanton-induced quark-antiquark interaction (III). A good description of the mass spectrum is obtained. The respective role of III and COGEP in the S-wave meson spectrum is discussed.

Light D wave meson spectrum in a relativistic harmonic model with instanton induced interaction

“…It should be noted that in the limit c  0, the central, tensor and spin-orbit part of the COGEP goes over to the corresponding potentials of the OGEP [3]. The central part of III potential is given by [8][9][10][11][12]16],…”

“…The parameters associated with the strange quark M s and A s 2 have been fitted in order to reproduce the magnetic moments of the strange baryons, according to the procedure described in [16]. The s  of COGEP is fixed from S wave meson spectroscopy [16].…”

“…We note that the  values can have both positive and negative values [8][9][10][11][12]. The values of the III parameters  's and  's are fixed from S and P wave meson spectroscopy [12,16] and are listed in Table 1 and 2.…”

“…Even in the existing relativistic models though the effect of confinement of quarks has been taken into account, the effect of confinement of gluons has not been taken into account [13][14][15]. Therefore in our present work, we have investigated the effect of exchange of confinement of gluons on the masses of light D wave mesons and their radially excited states in the frame work of RHM with III [6,[11][12]16]. The essential new ingredient in our investigation of the light D wave mesonic states is to take into account the confinement of gluons in addition to the confinement of quarks.…”

Electric polarizability of pions in semirelativistic quark model

“…In [31] it is shown within the QCD framework that, in order to describe the mass spectrum of light mesons well, it is enough to have only one parameter: string tension. In [32][33][34][35] the potential also does not contain the Coulomb part, since the Coulomb type interac tion is supposed to play a less important role for light mesons. Therefore, to estimate electric pion polariz ability, we shall use in this paper a linear potential of quark-antiquark interaction and a procedure devel oped in [20] on the basis of quantum mechanical per turbation theory.…”