Particle Physics and Quantum Field Theory
Tong-Wei Lin, Zun-Xian Zhang, Mengchu Cai, Hai-Yang Du, Bolun Hu, Xiangyu Jiang, Xiao-Lan Meng, Ji-Hao Wang, Peng Sun, Yi-Bo Yang, Dian-Jun Zhao, (CLQCD Collaboration)
We investigate the impact of including a dynamical charm quark on the properties of light hadrons. Our study compares the calculations performed on 2+1+1 flavor (highly improved staggered quark) ensembles at four lattice spacings to those on 2+1 flavor (clover fermion) ensembles at six lattice spacings, with both sets of ensembles employing the identical Symanzik gauge action. For the light, strange and charm flavor observables, we employ the same tadpole-improved clover fermion action. From numerical results for light and strange quark masses, pion and kaon decay constants, and $\Omega$ and $\Omega_{ccc}$ baryon masses, we find that the values obtained after continuum, chiral, and infinite-volume extrapolations are consistent within uncertainties. Even though the mixed action setup can introduce additional discretization effects, our calculation shows evidence that these effects can cancel with the discretization error in the unitary setup, resulting in better convergence in the continuum extrapolation.