摘要
We propose a strategy to access the qq component of the p resonance in lattice QCD. Through a mixed action formalism（overlap valence on domain wall sea）, the energy of the qq component is derived at different valence quark masses, and shows a linear dependence on mπ^2. The slope is determined to be c1 =0.505（3）GeV^-1, from which the valence πρ sigma term is extracted to be σ（πρ）^val= 9.82（6） MeV using the Feynman-Hellman theorem. At the physical pion mass, the mass of the qq component is interpolated to be mρ = 775.9±6.0±1.8 MeV, which is close to the p resonance mass. We also obtain the leptonic decay constant of the qq component to be fρ-=208.5±5.5±0.9 MeV, which can be compared with the experimental value fρ^exp≈221 MeV through the relation fρ^exp=（1/2）Zfρ±, with Zρ≈1.13 being the on-shell wavefunction renormalization of p owing to the ρ-π interaction. We emphasize that mρand fρ of the qq component, which are obtained for the first time from QCD, can be taken as the input parameters of p in effective field theory studies where p acts as a fundamental degree of freedom.
We propose a strategy to access the qq component of the p resonance in lattice QCD. Through a mixed action formalism（overlap valence on domain wall sea）, the energy of the qq component is derived at different valence quark masses, and shows a linear dependence on mπ^2. The slope is determined to be c1 =0.505（3）GeV^-1, from which the valence πρ sigma term is extracted to be σ（πρ）^val= 9.82（6） MeV using the Feynman-Hellman theorem. At the physical pion mass, the mass of the qq component is interpolated to be mρ = 775.9±6.0±1.8 MeV, which is close to the p resonance mass. We also obtain the leptonic decay constant of the qq component to be fρ-=208.5±5.5±0.9 MeV, which can be compared with the experimental value fρ^exp≈221 MeV through the relation fρ^exp=（1/2）Zfρ±, with Zρ≈1.13 being the on-shell wavefunction renormalization of p owing to the ρ-π interaction. We emphasize that mρand fρ of the qq component, which are obtained for the first time from QCD, can be taken as the input parameters of p in effective field theory studies where p acts as a fundamental degree of freedom.
作者
孙玮
Andrei Alexandru
陈莹
Terrence Draper
刘朝峰
杨一玻
Wei Sun;Andrei Alexandrua Ying Chen;Terrence Draper;Zhaofeng Liu;Yi-Bo Yang(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China;School of Physics, University of Chinese Academy of Sciences, Beijing 100049, China;Department of Physics, George Washington University, Washington, DC 20052, USA;Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506, USA;Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824, USA)
基金
Supported in part by the U.S.DOE Grant No.DE-SC0013065
the National Nature Science Foundation of China(NSFC)(11335001,11575196,11575197,11621131001)(CRC110 by DFG and NSFC)
by the National Science Foundation CAREER(PHY-1151648)
U.S.DOE(DE-FG02-95ER40907)
CAS Center for Excellence in Particle Physics(CCEPP)for their support
used the resources of the Oak Ridge Leadership Computing Facility at the Oak Ridge National Laboratory,which is supported by the Office of Science of the U.S.Department of Energy(DE-AC05-00OR22725)
