Lattice QCD Calculation of ππ Scattering Length  

作　　者：FU Zi-Wen 傅子文(Key Laboratory of Radiation Physics and Technology(Sichuan University),Ministry of Education,Institute of Nuclear Science and Technology,Sichuan University,Chengdu 610064,China)

机构地区：[1]Key Laboratory of Radiation Physics and Technology(Sichuan University),Ministry of Education,Institute of Nuclear Science and Technology,Sichuan University,Chengdu 610064,China

出　　处：《Communications in Theoretical Physics》2012年第1期78-84,共7页理论物理通讯（英文版）

基　　金：Supported by Fundamental Research Funds for the Central Universities under Grant No. 2010SCU23002;the Startup Grant fromthe Institute of Nuclear Science and Technology of Sichuan University

摘　　要：We study s-wave pion-pion scattering length in lattice QCD for pion masses ranging from 330 MeV to 466 MeV. In the ＂Asqtad＂ improved staggered fermion formulation, we measure full ππ four-point correlators for isospin I = 0 and 2 channels, and use chiral perturbation theory at next-to-leading order to extrapolate our simulation results. Extrapolating to the physical pion mass yields scattering lengths as mna01=2 = -0.041 6（2） and mna01= 0.186（2） for isospin I = 2 and 0 channels, respectively. Our lattice simulation for ππ scattering length in I = 0 channel is an exploratory study, where we include the disconnected contribution, and our preliminary result is near to its experimental value. These simulations are carried out with MILC 2 ＋ 1 flavor gauge configurations at lattice spacing a ≈0.15 fm.

关 键 词：lattice QCD energy shift scattering length four point function 

分 类 号：O572.33[理学—粒子物理与原子核物理] O436.2[理学—物理]