The first measurements of femtoscopic correlations with the particle pair combinations π±KS0 in pp collisions at s=13 TeV at the Large Hadron Collider (LHC) are reported by the ALICE experiment. Using the femtoscopic approach, it is shown that it is possible to study the elusive K0⁎(700) particle that has been considered a tetraquark candidate for over forty years. Source and final-state interaction parameters are extracted by fitting a model assuming a Gaussian source to the experimentally measured two-particle correlation functions. The final-state interaction in the π±KS0 system is modeled through a resonant scattering amplitude, defined in terms of a mass and a coupling parameter, The extracted mass and Breit–Wigner width, derived from the coupling parameter, of the final-state interaction are found to be consistent with previous measurements of the K0⁎(700). The small value and increase of the correlation strength with increasing source size support the hypothesis that the K0⁎(700) is a four-quark state, i.e. a tetraquark state of the form (q1,q2‾,q3,q3‾) in which q1, q2 and q3 indicate the flavor of the valence quarks of the π and KS0. This latter trend is also confirmed via a simple geometric model that assumes a tetraquark structure of the K0⁎(700) resonance.

中文翻译：

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研究大型强子对撞机中 K[公式省略]态的组成与 π±K[公式省略]相关性


ALICE 实验报告了大型强子对撞机 (LHC) s=13 TeV pp 碰撞中飞秒相关性与粒子对组合 π±KS0 的首次测量。使用飞秒方法，研究表明可以研究难以捉摸的 K0⁎(700) 粒子，四十多年来该粒子一直被认为是四夸克候选粒子。通过将假设高斯源的模型拟合到实验测量的两粒子相关函数来提取源和最终状态相互作用参数。 π±KS0 系统中的最终状态相互作用通过共振散射幅度进行建模，该共振散射幅度根据质量和耦合参数定义，最终状态的提取质量和 Breit-Wigner 宽度（从耦合参数导出）发现相互作用与之前的 K0⁎(700) 测量结果一致。随着源尺寸的增加，相关强度值较小且增加，支持 K0⁎(700) 是四夸克态的假设，即形式为 (q1,q2‾,q3,q3‾) 的四夸克态，其中q1、q2 和 q3 表示 π 和 KS0 的价夸克的味道。后一种趋势也通过一个简单的几何模型得到了证实，该模型假设 K0⁎(700) 共振的四夸克结构。