Chiral perturbation theory for hadron observables (A08)

我们格子工作的主要目的是获得现实的理论不确定性。为此，人们在晶格QCD中产生一些系综，并将特定物理量的所有结果外推到物理点(物理质量、零晶格常数、无限体积)。带误差条的数值结果的外推在数学上没有很好的定义，除非一个人可以约束允许的函数形式。手征微扰理论(ChPT)是一种成熟的有效场理论，它允许这样做。因此，我们结合A03、A07、A13、A14和A16项目使用SU(2)和SU(3)ChPT作为标准工具。在这样做的同时，我们还增加了关于低能量常数(LEC)的知识。

The main aim of our lattice work is to obtain realistic theoretical uncertainties. To do so, one generates in lattice QCD a number of ensembles and extrapolates all results for specific physical quantities to the physical point (physical mass, zero lattice constant, infinite volume). The extrapolation of numerical results with error bars is mathematically not well defined, unless one can constrain the allowed functional forms. Chiral perturbation theory (ChPT) is a well established effective field theory which allows to do so. Therefore, we use SU(2) and SU(3) ChPT in combination as standard tool in connection with the projects A03, A07, A13, A14 and A16. In doing so we also add to the knowledge of low energy constants (LECs).