@@ We study the σ meson in 2+1 flavor full quantum chromodynamics(QCD)with sufficiently light u and d quarks.The point-to-point correlator is measured for the σ channel in the"Asgtad"improved staggered fermion formulation.Particular attention is paid to its disconnected diagram and bubble contribution.After chiral extrapolation,we obtain the o mass with 706±53 Me V,which is close to the observed σ meson within error,and is heavier than the ππ threshold.The simulations are carried out with MILC 2+1 flavor gauge configurations at lattice spacing of a≈0.15 fm.
展开▼
Key Laboratory of Radiation Physics and Technology(Ministry of Education),Sichuan University,Institute of Nuclear Science and Technology,Sichuan University,Chengdu 610064;
