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arXiv 0812.1617nucl-th
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用手征组分夸克方法联合研究γ p到η p和π-p到η n

Combined study of gamma p to eta p and pi-p to eta n in a chiral constituent quark approach

Jun He, B. Saghai

摘要:

本文利用手征组分夸克模型方法,研究了质子{ \it via}电磁探针和强子探针上$η$ -介子的产生。在较少参数的情况下,给出了γp \to ηp $ and differential cross section for $ π^- p \to ηn $ processes are calculated and successfully compared with the data in the center-of-mass energy range from threshold up to 2 GeV. The five known resonances $ S_{11}(1535)$, $ S_{11}(1650)$, $ P_{13}(1720)$, $ D_{13}(1520)$, and $ F_{15}(1680)$ are found to be dominant in the reaction mechanisms in both channels. Possible roles plaied by new resonances are also investigated and in the photoproduction channel, significant contribution from $ S_{11} $- and $ D_{15} $-resonances, with masses around 1715 MeV and 2090 MeV, respectively, are deduced. For the so-called missing resonances, no evidence is found within the investigated reactions. The helicity amplitudes and decay widths of $ N^* \to πN,ηN$的微分截面和偏振光束不对称性。并发现与PDG值一致。

英文摘要:

Within a chiral constituent quark model approach, $η$-meson production on the proton {\it via} electromagnetic and hadron probes are studied. With few parameters, differential cross-section and polarized beam asymmetry for γp \to ηp$ and differential cross section for $π^- p\to ηn$ processes are calculated and successfully compared with the data in the center-of-mass energy range from threshold up to 2 GeV. The five known resonances $S_{11}(1535)$, $S_{11}(1650)$, $P_{13}(1720)$, $D_{13}(1520)$, and $F_{15}(1680)$ are found to be dominant in the reaction mechanisms in both channels. Possible roles plaied by new resonances are also investigated and in the photoproduction channel, significant contribution from $S_{11}$- and $D_{15}$-resonances, with masses around 1715 MeV and 2090 MeV, respectively, are deduced. For the so-called missing resonances, no evidence is found within the investigated reactions. The helicity amplitudes and decay widths of $N^* \to πN, ηN$ are also presented, and found consistent with the PDG values.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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