Title: Reconstruction of the vector meson propagator using a generalized eigenvalue problem Show Chinese title

Title: 使用广义特征值问题重构矢量介子传播子

Abstract: For long distances in the euclidean time the vector-vector correlator ($\rho$) has an exponentially decreasing signal-to-noise ratio. However, the vector correlator not only consists of the vector meson but also receives contributions from a two-pion system with the same quantum numbers. We measure all two-pion propagators with an energy lower than the mass of the resting vector meson and employ a generalized eigenvalue problem (GEVP) to resolve the different contributing energy states. Using those we can reconstruct the propagator with a much smaller noise at large euclidean time distances. In this work we present an efficient way to measure two-pion propagators and our results on reconstruction of the vector meson propagator with staggered fermions in a $(6^3\times 8.5)\,\textrm{fm}^4$ box. Show Chinese abstract

Abstract: 对于欧几里得时间中的长距离，矢量-矢量关联函数 ($\rho$) 具有指数衰减的信噪比。然而，矢量关联函数不仅由矢量介子组成，还接收具有相同量子数的两π子系统的贡献。我们测量所有能量低于静止矢量介子质量的两π子传播函数，并采用广义特征值问题 (GEVP) 来分辨不同的贡献能量态。利用这些，我们可以在大欧几里得时间距离下以更小的噪声重建传播函数。在本工作中，我们提出了一种有效测量两π子传播函数的方法，并给出了在$(6^3\times 8.5)\,\textrm{fm}^4$箱中使用阶梯费米子重建矢量介子传播函数的结果。