A quantitative criterion is proposed for testing the rationality of an effective QCD baryon theory.The higher order corrections of the standard SU(3)Skyrme model to the Gell-Mann-Okubo relations for baryons are studie...A quantitative criterion is proposed for testing the rationality of an effective QCD baryon theory.The higher order corrections of the standard SU(3)Skyrme model to the Gell-Mann-Okubo relations for baryons are studied according to the criterion,and some interesting results are presented.A possible prescription is recommended.展开更多
Under the scaling limit, i.e. T→T<sub>c</sub>+, H→O, R→∞, where h=const. H|T-T<sub>c</sub>|<sup>-15/8</sup> is fixed and small, while r=R|T-T<sub>c</sub>|is fixed an...Under the scaling limit, i.e. T→T<sub>c</sub>+, H→O, R→∞, where h=const. H|T-T<sub>c</sub>|<sup>-15/8</sup> is fixed and small, while r=R|T-T<sub>c</sub>|is fixed and large, we investigate the energy-spin correlation function 【σ<sub>M1</sub>, <sub>N1</sub>σ<sub>M2</sub>, <sub>N2</sub>ε<sub>N3</sub>, N3】 of Ising model with small external magnetic field. By cluster expansion we obtain its leading and next leading terms related to K<sub>0</sub>（nr） and K<sub>1</sub>（nr） up to order h<sup>2</sup>.展开更多
Based on 58 million J/ψ events collected by the BESⅡ detector at the BEPC, J/ψ→ΛΛ π＋π- is observed for the first time. The branching fraction is measured to be Br（J/ψ→ΛΛ π＋π-）=（4.30±0.13±0...Based on 58 million J/ψ events collected by the BESⅡ detector at the BEPC, J/ψ→ΛΛ π＋π- is observed for the first time. The branching fraction is measured to be Br（J/ψ→ΛΛ π＋π-）=（4.30±0.13±0.99）×10-3, excluding the decays to intermediate states, namely J/ψ→Ξ-Ξ＋, J/ψ→Σ（1385）-Σ（1385）＋, and J/ψ→Σ（1385）＋Σ（1385）-. The branching fractions for these intermediate resonance channels are measured to be：Br（J/ψ→Ξ-Ξ＋）=（0.90±0.03±0.18）×10-3, Br（J/ψ→Σ（1385）-Σ（1385）＋）=（1.23±0.07±0.30）×10-3,and Br（J/ψ→Σ（1385）＋Σ（1385）-）=（1.50±0.08±0.38）×10-3, respectively. The angular distribution is of the form dN/d（cosθ）α（1＋αcos2θ） with α=（0.35±0.29±0.06） for J/ψ→Ξ-Ξ＋, α=（-0.54±0.22±0.10） for J/ψ→Σ（1385）-Σ（1385）＋, and α=（-0.35±0.29±0.06） for J/ψ→Σ（1385）＋Σ（1385）-.展开更多
The decay ψ（2S）→Ω-Ω＋ is analyzed using 14×106 ψ（2S） events recorded by the Beijing Spectrometer Ⅱ （BESⅡ） at the Beijing Electron Positron Collider （BEPC）. Based upon events with no missing charged...The decay ψ（2S）→Ω-Ω＋ is analyzed using 14×106 ψ（2S） events recorded by the Beijing Spectrometer Ⅱ （BESⅡ） at the Beijing Electron Positron Collider （BEPC）. Based upon events with no missing charged tracks and a satisfactory four-constraint kinematic t, we determine the upper limit for the branching fraction of ψ（2S）→Ω-Ω＋ to be 1.5×104 at a 90% confidence level. By including events with one missing charged track, we are able to report the first evidence of an Ω＋ signal with a statistical signi cance of 3.1｜σ. The branching fraction of ψ（2S）Ω＋ is determined to be （4.80±1.56（stat）±1.30（sys））105.展开更多
基金Supported by the National Natural Science Foundation of China through C.N.Yanghe Science Fund of the Chinese Academy of Sciences.
文摘A quantitative criterion is proposed for testing the rationality of an effective QCD baryon theory.The higher order corrections of the standard SU(3)Skyrme model to the Gell-Mann-Okubo relations for baryons are studied according to the criterion,and some interesting results are presented.A possible prescription is recommended.
基金Project supported in part by the National Natural Science Foundation of China.
文摘Under the scaling limit, i.e. T→T<sub>c</sub>+, H→O, R→∞, where h=const. H|T-T<sub>c</sub>|<sup>-15/8</sup> is fixed and small, while r=R|T-T<sub>c</sub>|is fixed and large, we investigate the energy-spin correlation function 【σ<sub>M1</sub>, <sub>N1</sub>σ<sub>M2</sub>, <sub>N2</sub>ε<sub>N3</sub>, N3】 of Ising model with small external magnetic field. By cluster expansion we obtain its leading and next leading terms related to K<sub>0</sub>（nr） and K<sub>1</sub>（nr） up to order h<sup>2</sup>.
基金Supported by National Natural Science Foundation of China(10491300,10225524,10225525,10425523,10625524,10521003,10821063,10825524)Chinese Academy of Sciences(KJ95T-03)+3 种基金100Talents Program of CAS(U-11,U-24,U-25)Knowledge Innovation Project of CAS(U-602,U-34)(IHEP)National Natural Science Foundation of China(10775077,10225522)(Tsinghua University)Department of Energy(DE-FG02-04ER41291)(U.Hawaii)
文摘Based on 58 million J/ψ events collected by the BESⅡ detector at the BEPC, J/ψ→ΛΛ π＋π- is observed for the first time. The branching fraction is measured to be Br（J/ψ→ΛΛ π＋π-）=（4.30±0.13±0.99）×10-3, excluding the decays to intermediate states, namely J/ψ→Ξ-Ξ＋, J/ψ→Σ（1385）-Σ（1385）＋, and J/ψ→Σ（1385）＋Σ（1385）-. The branching fractions for these intermediate resonance channels are measured to be：Br（J/ψ→Ξ-Ξ＋）=（0.90±0.03±0.18）×10-3, Br（J/ψ→Σ（1385）-Σ（1385）＋）=（1.23±0.07±0.30）×10-3,and Br（J/ψ→Σ（1385）＋Σ（1385）-）=（1.50±0.08±0.38）×10-3, respectively. The angular distribution is of the form dN/d（cosθ）α（1＋αcos2θ） with α=（0.35±0.29±0.06） for J/ψ→Ξ-Ξ＋, α=（-0.54±0.22±0.10） for J/ψ→Σ（1385）-Σ（1385）＋, and α=（-0.35±0.29±0.06） for J/ψ→Σ（1385）＋Σ（1385）-.
基金Supported by National Natural Science Foundation of China （10491300, 10225524, 10225525, 10425523, 10625524, 10521003, 10821063, 10825524）, Chinese Academy of Sciences （KJ 95T-03）, 100 Talents Program of CAS （U-11, U-24, U-25）, Knowledge Innovation Project of CAS （U-602, U-34 （IHEP））, National Natural Science Foundation of China （10775077, 10225522） （Tsinghua University）, and Department of Energy （DE-FG02-04ER41291） （U. Hawaii）
文摘The decay ψ（2S）→Ω-Ω＋ is analyzed using 14×106 ψ（2S） events recorded by the Beijing Spectrometer Ⅱ （BESⅡ） at the Beijing Electron Positron Collider （BEPC）. Based upon events with no missing charged tracks and a satisfactory four-constraint kinematic t, we determine the upper limit for the branching fraction of ψ（2S）→Ω-Ω＋ to be 1.5×104 at a 90% confidence level. By including events with one missing charged track, we are able to report the first evidence of an Ω＋ signal with a statistical signi cance of 3.1｜σ. The branching fraction of ψ（2S）Ω＋ is determined to be （4.80±1.56（stat）±1.30（sys））105.
