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arXiv 2603.28337hep-phnucl-th
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K$^*$Σ光产生反应中截面数据和自旋密度矩阵元的综合分析

Combined analysis of the data on cross sections and spin density matrix elements for $K^*Σ$ photoproduction reactions

School of Nuclear Science and Technology, University of Chinese Academy of Sciences(中国科学院大学核科学与技术学院);College of Science, China University of Petroleum (East China)(中国石油大学(华东)理学院);School of Physics, Henan Normal University(河南师范大学物理学院)

Ai-Chao Wang, Neng-Chang Wei, Fei Huang

AI总结:

本文通过结合CLAS和LEPS实验数据,利用有效拉格朗日方法分析K$^*$Σ光产生反应,发现Δ(1905)5/2$^+$共振及κ交换对反应机制有重要影响,且不同拟合结果中κ交换贡献存在显著差异。

摘要:

在先前的工作[Phys. Rev. C 98, 045209 (2018)]中,我们利用有效拉格朗日方法分析了CLAS合作组提供的反应γp→K*+Σ0和γp→K*0Σ+的微分截面数据。我们发现,为了合理描述数据,需要包括s通道Δ(1905)5/2+共振,以及t通道交换的K、κ、K*,s通道来自核子(N)和Δ,u通道交换的Λ、Σ和Σ*,以及广义接触项。在本工作中,我们扩展分析以纳入LEPS合作组提供的γp→K*0Σ+反应在光子能量Eγ=1.85--2.96 GeV的数据。我们的目标是对理论模型施加更严格的约束,并获得对反应机制更可靠的理解。我们得到两个拟合结果,这两个拟合结果对实验数据的描述同样良好。在两个拟合中,Δ(1905)5/2+共振起着重要作用。然而,在一个拟合中t通道κ交换的贡献显著,而在另一个拟合中则可以忽略不计。这一发现与文献中先前声称LEPS偏振 asymmetry P_σ数据支持κ交换在γp→K*0Σ+反应中起主导作用的观点相矛盾。我们还对Eγ=8.5 GeV时的P_σ进行了预测,这可能有助于澄清κ交换是否确实在该反应中起主导作用。

英文摘要:

In our earlier work [Phys. Rev. C \textbf{98}, 045209 (2018)], we analyzed the differential cross-section data from the CLAS Collaboration for the reactions $γp \to K^{*+}Σ^0$ and $γp \to K^{*0} Σ^+$ using an effective Lagrangian approach. We found that a satisfactory description of the data required the inclusion of the $s$-channel $Δ(1905)5/2^+$ resonance, in addition to $t$-channel exchanges of $K$, $κ$, and $K^*$, $s$-channel contributions from nucleons ($N$) and $Δ$, $u$-channel exchanges of $Λ$, $Σ$, and $Σ^*$, and a generalized contact term. In the present work, we extend our analysis to incorporate the data on spin density matrix elements from the LEPS Collaboration for the $γp \to K^{*0}Σ^+$ reaction at photon energies $E_γ = 1.85$--$2.96$ GeV. Our goal is to impose more stringent constraints on the theoretical model and obtain a more reliable understanding of the reaction mechanisms. We obtain two fits that describe the experimental data equally well. In both fits, the $Δ(1905)5/2^+$ resonance plays an important role. However, the contribution from $t$-channel $κ$ exchange is significant in one fit but negligible in the other. This finding contradicts earlier claims in the literature that the LEPS parity spin asymmetry $P_σ$ data support a dominant role of $κ$ exchange in $γp \to K^{*0}Σ^+$. We also present predictions for $P_σ$ at $E_γ= 8.5$ GeV, which may help clarify whether $κ$ exchange is indeed dominant in this reaction.

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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