AI 中文总结
本研究首次对两个纯I=1的$K_Lp$反应开展相位约束联合分析，通过有效拉格朗日模型拟合得到卡方/自由度为1.604，揭示了两道的互补性与相关超子共振的作用，为超子谱研究和JLab未来测量提供支撑。
AI 中文摘要
低能反K核子（$\bar K N$）散射是研究奇异重子谱学的直接途径，但传统的带电K介子反应会混合同位旋I=0与I=1的振幅。受$K_Lp$反应同位旋选择特性的启发，我们开展了据我们所知首次对纯I=1反应$K_Lp\toπ^+Σ^0$和$K_Lp\toπ^+Λ$的联合分析，对两个末态施加了统一的共振参数组与固定的相对相位约定。在有效拉格朗日模型框架下，对已有的微分截面和反冲极化数据进行联合拟合，得到的$χ^2/\mathrm{d.o.f.}$（卡方/自由度）为1.604。我们发现了清晰的道互补性：t道$K^*$交换在$K_L p\to π^+Λ$反应中更为重要，尤其是在小角度区域；而$K_L p\to π^+Σ^0$反应则对$Σ(1620)\\,1/2^-$的贡献更敏感。同时，$Σ(1660)\\,1/2^+$通过干涉效应在两个反应道中都保持重要作用。这些结果证明了多通道、相位约束分析对于确立I=1超子谱的重要性，并为杰斐逊实验室（JLab）KLF项目未来的高精度测量提供了及时的唯象学输入。一旦纯I=1振幅得到可靠测定，它们还将能够从数量多得多的$K^- p\to π^\pmΣ^\mp$数据中分离出I=0分量，为更定量地研究$Λ^*$谱开辟道路。
英文摘要
Low-energy $\bar K N$ scattering provides direct access to strange-baryon spectroscopy, but conventional charged-kaon reactions mix the $I=0$ and $I=1$ amplitudes. Motivated by the isospin-selective nature of the $K_Lp$ reactions, we present, to our knowledge, the first simultaneous analysis of the pure-$I=1$ reactions $K_Lp\toπ^+Σ^0$ and $K_Lp\toπ^+Λ$ in which a common set of resonance parameters and a fixed relative-phase convention are imposed on both final states. Within an effective-Lagrangian model, a joint fit of available differential cross sections and recoil polarizations yields $χ^2/\mathrm{d.o.f.}=1.604$. We find clear channel complementarity: the $t$-channel $K^*$ exchange is more important in $K_L p\to π^+Λ$, especially at forward angles, whereas $K_L p\to π^+Σ^0$ is more sensitive to the contribution of $Σ(1620)\,1/2^-$. At the same time, $Σ(1660)\,1/2^+$ remains important through interference effects in both channels. These results demonstrate the importance of multichannel, phase-constrained analyses for establishing the $I=1$ hyperon spectrum and provide timely phenomenological input for future high-precision measurements by the KLF program at JLab. Once the pure $I=1$ amplitudes are reliably determined, they will also enable the separation of the $I=0$ component in the much more abundant $K^- p\to π^\pmΣ^\mp$ data, opening a path toward a more quantitative study of the $Λ^*$ spectrum.
Comments6+8 pages, 3+4 figures
