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arXiv 1608.01508hep-phhep-exnucl-exnucl-th
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核子外标量介子$f_0(500)$和$f_0(980)$的光生

Photoproduction of the scalar mesons $f_0(500)$ and $f_0(980)$ off the nucleon

Je-Hee Lee, Hyun-Chul Kim, Sang-Ho Kim, Hui-Young Ryu, Byung-Geel Yu

摘要:

我们研究光生标量介子的核子,使用有效的拉格朗日和Regge方法。我们首先研究了$f_0(980)$的光生作用,用Regge传播子代替费曼传播子,研究了$t$ -通道中的$ρ$ -介子交换。通过再现微分截面上的实验数据来确定模型参数。然后,我们将相同的方法应用于$f_0(500)$或$σ$的光生,具有相同的参数的Regge传播。由于产生$f_0(500)$的阈值能量相当低,所以$N^*$共振可以在$s$ -通道中发挥作用,该共振可以衰变为处于等序态和标量态的核子和两个π介子。为了检查$N^*$共振的影响,我们建立了两个模型来研究$N^*$共振的各自贡献。我们发现特别是$N^*(1440)$和$N^*(1680)$在$f_0(500)$光产生中起重要作用。我们讨论了目前的结果的物理意义。

英文摘要:

We investigate photoproduction of the scalar mesona off the nucleon, using the effective Lagrangians and the Regge approach. We first study $f_0(980)$ photoproduction, replacing the Feynman propagator with the Regge ones for the $ρ$-meson exchange in the $t$-channel. The model parameters are fixed by reproducing the experimental data on the differential cross section. We then apply the same method to $f_0(500)$ or $σ$ photoproduction with the same parameters for the Regge propagator. Since the threshold energy of the $f_0(500)$ production is rather low, $N^*$ resonances, which can decay into the nucleon and two pions in the isoscalar and scalar state, can come into play in the $s$-channel. To examine the effects of the $N^*$ resonances, we set up two models to look into the respective contribution of the $N^*$ resonances. We find that in particular $N^*(1440)$ and $N^*(1680)$ play important roles in $f_0(500)$ photoproduction. We discuss the physical implications of the present results.

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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