S- and P-wave meson spectroscopy in the nonrelativistic quark model

Abstract

The mass spectrum of the ground state 1S 0 , 3S 1 and orbitally excited 3P 0 , 1P 1 , 3P 1 , 3P 2 mesons is considered in a nonrelativistic constituent quark model. A good description of the mass spectrum of these mesons is obtained with the same constituent quark masses m u = m d =305±2 and m s =483±3 MeV/ c 2. It is suggested that the nonrelativistic quark model describes better the masses of “bare” q q ̄ states, such as found in the K-matrix analysis, than the measured ones, at least for such broad states as the K ∗ 0(1430) . The a 0(980) is a quarkonium in this scheme and belongs to the lightest scalar nonet together with the K ∗ 0(1430) , with the “bare” q q ̄ mass 1191±8 MeV/ c 2, f 0(980) and f 0(1370). The extracted value of the K 1( 3P 1)−K 1( 1P 1) mixing angle ( θ K ) is (31±4)°. A constant in the mass formulae for P-wave mesons might be interpreted as the effective gluon “mass”.