https://doi.org/10.1140/epja/i2009-10876-4
Regular Article - Theoretical Physics
Understanding light scalar meson by color-magnetic wave function in QCD sum rule
1
Kavli Institute for Theoretical Physics China, Key Laboratory of Frontiers in Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, 100190, Beijing, PRC
2
Interdisciplinary Center of Theoretical Studies, University of Science and Technology of China, 230026, Hefei, Anhui, PRC
* e-mail: yipang@itp.ac.cn
Received:
26
July
2009
Revised:
3
September
2009
Accepted:
14
September
2009
Published online:
9
October
2009
In this paper, we study the 0+ nonet mesons as tetraquark states with interpolating currents inspired by the color-magnetic wave function. This wave function is the eigenfunction of an effective color-magnetic Hamiltonian with the lowest eigenvalue, meaning that the state depicted by this wave function is the most stable one and is the most probable to be observed in experiments. We perform an OPE calculation up to dimension-eight condensates and find that the best QCD sum rule is achieved when the current inspired by the color-magnetic wave function is a proper mixture of the tensor and pseudoscalar diquark-antidiquark bound states. Compared with previous results, to sigma(600) and kappa(800), our results appear better, due to larger pole contribution. The direct instanton contributions are also considered, which yields a consistent result with previous OPE results. Finally, we also discuss the 
problem as a possible six-quark state.
PACS: 12.38.Cy Summation of perturbation theory – / 12.38.Lg Other nonperturbative calculations – / 12.39.Mk Glueball and nonstandard multi-quark/gluon states – / 12.40.Yx Hadron mass models and calculations –
© SIF, Springer-Verlag Berlin Heidelberg, 2009
