标题： 基于波函数的格点QCD中两粒子系统的算符优化 显示英文标题

标题： Wavefunction-based operator optimization for two-hadron systems in lattice QCD

摘要： 一种系统的方法用于构建两介子系统的优化插值算符，该方法结合了介子间的空间波函数。 这些波函数可以通过一个带有适当初始猜测的迭代过程获得。 为了实现这些算符，提出了一种利用$Z_3$噪声向量的新颖夸克平滑技术，这使得在不使用全对全夸克传播子的情况下，能够有效地将介子间空间波函数包含在源中。 对使用物理点格点配置的大尺寸$La\simeq8.1$~fm 的$\Omega_{ccc}\Omega_{ccc}$系统进行原理验证应用表明，优化的算符能够清晰地识别出围绕$2m_{\Omega_{ccc}}\simeq 9700$MeV 的状态，其能量间隙小至$\sim 5$MeV。 给出了未优化算符和优化算符之间的关联函数、有效能量和HAL QCD势的比较，并特别强调了附近弹性散射态的影响。 还讨论了优化算符在各种两介子系统中的潜在应用及其与变分法的关系。 显示英文摘要

摘要： A systematic way to constructing optimized interpolating operators for two-hadron systems is developed by incorporating inter-hadron spatial wavefunctions. The wavefunctions can be obtained from an iterative process with an appropriate initial guess. To implement these operators, a novel quark smearing technique utilizing $Z_3$ noise vectors is proposed, which allows for effectively incorporating inter-hadron spatial wavefunctions at the source without using all-to-all quark propagators. Proof-of-principle application to the $\Omega_{ccc}\Omega_{ccc}$ system using physical-point lattice configurations with a large size $La\simeq8.1$~fm shows that optimized operators enables clear identification of states around $2m_{\Omega_{ccc}}\simeq 9700$ MeV with the energy gap as narrow as $\sim 5$ MeV. A comparison on correlation functions, effective energies, and HAL QCD potentials between unoptimized operators and optimized operators is given, with a special emphasis on the effects from nearby elastic scattering states. Potential applicability of the optimized operator to various two-hadron systems and its relation to the variational method are also discussed.