Ground State Mass Spectrum for Scalar Diquarks with Bethe-Salpeter Equation  

作　　者：WANG Zhi-Gang WAN Shao-Long YANG Wei-Min 

机构地区：[1]Department of Physics, North China Electric Power University, Baoding 071003, China [2]Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China

出　　处：《Communications in Theoretical Physics》2007年第2期287-292,共6页理论物理通讯（英文版）

基　　金：The project supported by National Natural Science Foundation of China under Grant No. 10405009 The authors are indebted to Dr： J. He （IHEP）, Dr. X.B. nuang （PKU） and Dr. L. Li （GSCAS） for numerous help. Without them, the work would not be finished. The authors would also like to thank Prof. C.D. Roberts for providing us some important literatures.

摘　　要：In this article, we study the structures of the pseudoscalar mesons π, K and the scalar diquarks U^a, D^a, Sa in the framework of the coupled rainbow Schwinger-Dyson equation and ladder Bethe-Salpeter equation with the confining effective potential. The u, d, s quarks have small current masses, and the renormalization is very large, the mass poles in the timelike region are absent which implements confinement naturally. The Bethe-Salpeter wavefunctions of the pseudoscalar mesons π, K, and the scalar diquarks U^a, D^a, S^a have the same type （Gaussian type） momentum dependence, center around zero momentum and extend to the energy scale about q^2 = 1 GeV^2, which happens to be the energy scale for the chiral symmetry breaking, the strong interactions in the infrargd region result in bound （or quasl-bound） states. The numerical results for the masses and decay constants of the π and K mesons can reproduce the experimental values, and the ground state masses of the scalar diquarks U^a, D^a, S^a are consistent with the existing theoretical calculations. We suggest a new Lagrangian which may explain the uncertainty of the masses of the scalar diauarks.

关 键 词：Schwinger-Dyson equation Bethe-Salpeter equation DIQUARK CONFINEMENT 

分 类 号：O572.243[理学—粒子物理与原子核物理]