In this work, we employ the Bethe-Salpeter （B-S） equation to investigate the spectra of free diquarks and their B-S wave functions. We find that the B-S approach can be consistently applied to study the diqaurks wit...In this work, we employ the Bethe-Salpeter （B-S） equation to investigate the spectra of free diquarks and their B-S wave functions. We find that the B-S approach can be consistently applied to study the diqaurks with two heavy quarks or one heavy and one light quarks, but for two light-quark systems, the results are not reliable. There are a few free parameters in the whole scenario which can only be fixed phenomenologically. Thus, to determine them, one has to study baryons which are composed of quarks and diquarks.展开更多
Bound states, such as qq and q^-q, may exist the volume of the bound states may evoke a reduction in investigate qualitatively the volume effect on the properties states start to be completely melted.
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 t...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.展开更多
The effective potential analysis indicates that, in a 3D two-flavor Gross-Neveu model in vacuum, depending on whether Gs/Hp is less or bigger than the critical value 2/3, where G s and H p are respectively the couplin...The effective potential analysis indicates that, in a 3D two-flavor Gross-Neveu model in vacuum, depending on whether Gs/Hp is less or bigger than the critical value 2/3, where G s and H p are respectively the coupling constants of scalar quark-antiquark channel and pseudoscalar diquark channel, the system will have the ground state with pure diquark condensates or with pure quark-antiquark condensates, but never with coexistence of the two forms of condensates. The similarities and differences in the interplay between the quark-antiquark and the diquark condensates in vacuum in the 2D, 3D and 4D two-flavor four-fermion interaction models are summarized.展开更多
基金The project partly supported by National Natural Science Foundation of China and the Special Fund for the Doctorate Programs of Universities. We highly benefit from discussions with Prof. C.H. Chang, who kindly introduces their new methods for numerically solving the B-S equation to us and indicates some important physics problems which we did not notice.
文摘In this work, we employ the Bethe-Salpeter （B-S） equation to investigate the spectra of free diquarks and their B-S wave functions. We find that the B-S approach can be consistently applied to study the diqaurks with two heavy quarks or one heavy and one light quarks, but for two light-quark systems, the results are not reliable. There are a few free parameters in the whole scenario which can only be fixed phenomenologically. Thus, to determine them, one has to study baryons which are composed of quarks and diquarks.
基金The project supported in part by National Natural Science Foundation of China under Grant Nos. 90103019 and 10428510.We thank professor Yu-Xin Liu for useful discussions,
文摘Bound states, such as qq and q^-q, may exist the volume of the bound states may evoke a reduction in investigate qualitatively the volume effect on the properties states start to be completely melted.
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.
文摘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.
基金The project supported by National Natural Science Foundation of China under Grant No. 10475113
文摘The effective potential analysis indicates that, in a 3D two-flavor Gross-Neveu model in vacuum, depending on whether Gs/Hp is less or bigger than the critical value 2/3, where G s and H p are respectively the coupling constants of scalar quark-antiquark channel and pseudoscalar diquark channel, the system will have the ground state with pure diquark condensates or with pure quark-antiquark condensates, but never with coexistence of the two forms of condensates. The similarities and differences in the interplay between the quark-antiquark and the diquark condensates in vacuum in the 2D, 3D and 4D two-flavor four-fermion interaction models are summarized.
