Here we employ the extended chiral constituent quark model to investigate the five-quark components in the N＊ （1535） resonance. The axial charge of N＊（1535） and the electromagnetic transition γ＊N → N＊（1535...Here we employ the extended chiral constituent quark model to investigate the five-quark components in the N＊ （1535） resonance. The axial charge of N＊（1535） and the electromagnetic transition γ＊N → N＊（1535） are also analyzed. The results show that there may be sizable strangeness component in N＊（1535）.展开更多
The strong decays of the N*(1535) resonance are investigated in an extended chiral quark model by including the low-lying qqqqq components in addition to the qqq component.The results show that these five-quark compon...The strong decays of the N*(1535) resonance are investigated in an extended chiral quark model by including the low-lying qqqqq components in addition to the qqq component.The results show that these five-quark components in N*(1535) contribute significantly to the N*(1535)→ Nπ and N*(1535) → Nη decays.The contributions to the Nη decay come from both the lowest energy and the next-to-lowest energy five-quarks components,while the contributions to the Nπ decay come from only the latter one.Taking these contributions into account,the description for the strong decays of N*(1535) is improved,especially for the puzzling large ratio of the decays to Nη and Nπ.展开更多
The spin structure of nucleons is presented in the framework of an extended quark model which in addition to the conventional qqq structure also takes into account qqqq admixtures in the nucleon wave functions, where ...The spin structure of nucleons is presented in the framework of an extended quark model which in addition to the conventional qqq structure also takes into account qqqq admixtures in the nucleon wave functions, where the qqqq components are in colored quark cluster configurations. The axial vector weak coupling constant and spin distributions for polarized nucleons as well as spin content are obtained for the lowest positive parity qqqq configurations in flavor-spin dependent interaction. In particular, the contributions of the down and strange quarks to the proton spin and the sum rule for polarized neutron are negative, in agreement with recent experiments.展开更多
文摘Here we employ the extended chiral constituent quark model to investigate the five-quark components in the N＊ （1535） resonance. The axial charge of N＊（1535） and the electromagnetic transition γ＊N → N＊（1535） are also analyzed. The results show that there may be sizable strangeness component in N＊（1535）.
基金Supported by the National Natural Science Foundation of China (Grant Nos.10875133 and 10821063)the Chinese Academy of Sciences(Grant No.KJCX3-SYW-N2)
文摘The strong decays of the N*(1535) resonance are investigated in an extended chiral quark model by including the low-lying qqqqq components in addition to the qqq component.The results show that these five-quark components in N*(1535) contribute significantly to the N*(1535)→ Nπ and N*(1535) → Nη decays.The contributions to the Nη decay come from both the lowest energy and the next-to-lowest energy five-quarks components,while the contributions to the Nπ decay come from only the latter one.Taking these contributions into account,the description for the strong decays of N*(1535) is improved,especially for the puzzling large ratio of the decays to Nη and Nπ.
基金Supported by National Natural Foundation of China (10575083)
文摘The spin structure of nucleons is presented in the framework of an extended quark model which in addition to the conventional qqq structure also takes into account qqqq admixtures in the nucleon wave functions, where the qqqq components are in colored quark cluster configurations. The axial vector weak coupling constant and spin distributions for polarized nucleons as well as spin content are obtained for the lowest positive parity qqqq configurations in flavor-spin dependent interaction. In particular, the contributions of the down and strange quarks to the proton spin and the sum rule for polarized neutron are negative, in agreement with recent experiments.
