Light scalar mesons in the improved ladder QCD
Light scalar mesons in the improved ladder QCD
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DOI：
10.1103/physrevc.70.055205
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发表时间：
2004-03
影响因子：
3.1
通讯作者：
T. Umekawa;K. Naito;M. Oka;M. Takizawa
中科院分区：
文献类型：
--
作者：
T. Umekawa;K. Naito;M. Oka;M. Takizawa
The light scalar meson spectrum is studied using the improved ladder QCD with the U{sub A}(1) breaking Kobayashi-Maskawa-'t Hooft interaction by solving the Schwinger-Dyson and Bethe-Salpeter equations. The dynamically generated momentum-dependent quark mass is large enough in the low momentum region to give rise to the spontaneous breaking of chiral symmetry. Due to the large dynamical quark mass, the scalar mesons become the qq bound states. Since the parameters have been all fixed to reproduce the light pseudoscalar meson masses and the decay constant, there is no free parameter in the calculation of the scalar mesons. We obtain M{sub {sigma}}=667 MeV, M{sub a{sub 0}}=942 MeV, and M{sub f{sub 0}}=1336 MeV. They are in good agreement with the observed masses of {sigma}(600), a{sub 0}(980), and f{sub 0}(1370), respectively. We therefore conclude that these states are the members of the light scalar meson nonet. The mass of K{sub 0}{sup *} is obtained between that of a{sub 0} and f{sub 0} and the corresponding state is not observed experimentally. We also find that the strangeness content in the {sigma} meson is about 5%.
The light scalar meson spectrum is studied using the improved ladder QCD with the U{sub A}(1) breaking Kobayashi-Maskawa-'t Hooft interaction by solving the Schwinger-Dyson and Bethe-Salpeter equations. The dynamically generated momentum-dependent quark mass is large enough in the low momentum region to give rise to the spontaneous breaking of chiral symmetry. Due to the large dynamical quark mass, the scalar mesons become the qq bound states. Since the parameters have been all fixed to reproduce the light pseudoscalar meson masses and the decay constant, there is no free parameter in the calculation of the scalar mesons. We obtain M{sub {sigma}}=667 MeV, M{sub a{sub 0}}=942 MeV, and M{sub f{sub 0}}=1336 MeV. They are in good agreement with the observed masses of {sigma}(600), a{sub 0}(980), and f{sub 0}(1370), respectively. We therefore conclude that these states are the members of the light scalar meson nonet. The mass of K{sub 0}{sup *} is obtained between that of a{sub 0} and f{sub 0} and the corresponding state is not observed experimentally. We also find that the strangeness content in the {sigma} meson is about 5%.