We calculated the nucleon self-energies in iso-spin asymmetric nuclear matter and obtained the nuclear symmetry energy by taking difference of these of neutron and proton.We find that the scalar(vector) self-energy pa...We calculated the nucleon self-energies in iso-spin asymmetric nuclear matter and obtained the nuclear symmetry energy by taking difference of these of neutron and proton.We find that the scalar(vector) self-energy part gives a negative(positive) contribution to the nuclear symmetry energy,consistent with the result from relativistic mean-field theories.Also,we found exact four-quark operator product expansion for nucleon sum rule.Among them,twist-4 matrix elements which can be extracted from deep inelastic scattering experiment constitute an essential part in the origin of the nuclear symmetry energy from QCD.Our result also extends early success of QCD sum rule in the symmetric nuclear matter to the asymmetric nuclear matter.展开更多
In this article, we calculate the contribution from the nonfactorizable soft hadronic matrix element to the decay B^0→Xc1π^0 with the light-cone quantum chromo-dynamic （QCD） sum rules. The numerical results show t...In this article, we calculate the contribution from the nonfactorizable soft hadronic matrix element to the decay B^0→Xc1π^0 with the light-cone quantum chromo-dynamic （QCD） sum rules. The numerical results show that its contribution is rather large and should not be neglected. The total amplitudes lead to a branching fraction which is in agreement with the experimental data marginally.展开更多
基金Supported by Korea national researchfoundation(Grants Nos.KRF-2011-0030621 and KRF-2011-0020333)
文摘We calculated the nucleon self-energies in iso-spin asymmetric nuclear matter and obtained the nuclear symmetry energy by taking difference of these of neutron and proton.We find that the scalar(vector) self-energy part gives a negative(positive) contribution to the nuclear symmetry energy,consistent with the result from relativistic mean-field theories.Also,we found exact four-quark operator product expansion for nucleon sum rule.Among them,twist-4 matrix elements which can be extracted from deep inelastic scattering experiment constitute an essential part in the origin of the nuclear symmetry energy from QCD.Our result also extends early success of QCD sum rule in the symmetric nuclear matter to the asymmetric nuclear matter.
基金supported by the National Natural Science Foundation of China (Grant No 10775051)the Program for New Century Excellent Talents in University of China (Grant No NCET-07-0282)
文摘In this article, we calculate the contribution from the nonfactorizable soft hadronic matrix element to the decay B^0→Xc1π^0 with the light-cone quantum chromo-dynamic （QCD） sum rules. The numerical results show that its contribution is rather large and should not be neglected. The total amplitudes lead to a branching fraction which is in agreement with the experimental data marginally.
