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arXiv 1908.01139hep-phnucl-th
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$γp \to ωp$反应中的核子共振

Nucleon resonances in $γp \to ωp$ reaction

N. C. Wei, F. Huang, K. Nakayama, D. M. Li

摘要:

本文用有效拉格朗日方法分析了CLAS合作组报告的关于自旋观测量$Σ$、$T$、$P'$、$E$、$F$和$H$的最新高精度数据,以及CLAS、A2、GRAAL、SAPHIR和CBELSA/TAPS合作组报告的关于反应$γp \to ωp$的微分截面和自旋密度矩阵元的先前数据。通过考虑$t$通道的$π$和$η$交换、$s$通道的核子和核子共振交换、$u$通道的核子交换和广义接触电流,构造了反应振幅.后者有效地占的相互作用电流,并确保完整的光生振幅是规范不变的。它表明,所有可用的CLAS数据可以令人满意地描述考虑的$N(1520)3/2^-$,$N(1700)3/2^-$,$N(1720)3/2^+$,$N(1860)5/2^+$,$N(1875)3/2^-$,$N(1895)1/2^-$和$N(2060)5/2^-$共振的$s$通道。这些共振的参数提取和比较引用的PDG。

英文摘要:

The most recent high-precision data on spin observables $Σ$, $T$, $P'$, $E$, $F$ and $H$ reported by the CLAS Collaboration together with the previous data on differential cross sections and spin-density-matrix elements reported by the CLAS, A2, GRAAL, SAPHIR and CBELSA/TAPS Collaborations for the reaction $γp \to ωp$ are analyzed within an effective Lagrangian approach. The reaction amplitude is constructed by considering the $t$-channel $π$ and $η$ exchanges, the $s$-channel nucleon and nucleon resonances exchanges, the $u$-channel nucleon exchange and the generalized contact current. The latter accounts effectively for the interaction current and ensures that the full photoproduction amplitude is gauge invariant. It is shown that all the available CLAS data can be satisfactorily described by considering the $N(1520)3/2^-$, $N(1700)3/2^-$, $N(1720)3/2^+$, $N(1860)5/2^+$, $N(1875)3/2^-$, $N(1895)1/2^-$ and $N(2060)5/2^-$ resonances in the $s$-channel. The parameters of these resonances are extracted and compared with those quoted by PDG.

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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