馈入效应对$Λ$自旋极化的影响
Feed-down effect on $Λ$ spin polarization
摘要：
我们发展了一个理论框架来研究高位奇异重子对$Λ$超子自旋极化的反馈效应。在这个框架下，我们考虑通过强，电磁和弱过程的两体衰变，并通过采用螺旋度形式主义推导出子粒子的角分布和自旋极化的一般公式。使用现实的实验数据作为输入，我们探讨了反馈的贡献，全球和本地的$Λ$偏振，并发现这样的贡献抑制原始$Λ$偏振，这是不够强，以解决目前的理论和实验结果之间的差异的方位角依赖的$Λ$偏振。我们的论文也可以用于测量比$Λ$重的重子的自旋极化（例如，$Ξ^-$）。
英文摘要：
We develop a theoretical framework to study the feed-down effect of higher-lying strange baryons on the spin polarization of the $Λ$ hyperon. In this framework, we consider two-body decays through strong, electromagnetic, and weak processes and derive general formulas for the angular distribution and spin polarization of the daughter particle by adopting the helicity formalism. Using the realistic experimental data as input, we explore the feed-down contribution to the global and the local $Λ$ polarizations and find that such a contribution suppresses the primordial $Λ$ polarization, which is not strong enough to resolve the discrepancy between the current theoretical and the experimental results on the azimuthal-angle dependence of $Λ$ polarization. Our paper may also be useful for the measurement of spin polarization of baryons heavier than $Λ$ (e.g., $Ξ^-$) in future experiments.
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。
