标题： Ginsparg-Wilson pion散射在交错夸克的海中 显示英文标题

标题： Ginsparg-Wilson Pions Scattering in a Sea of Staggered Quarks

摘要： 我们计算了部分淬火、混合作用理论中味同位旋为2的π-π散射，其中海夸克是staggered的，而价夸克是Ginsparg-Wilson的，均在手征微扰论框架下。 我们指出，对于某些散射道，在非幺正理论（如部分淬火或混合作用QCD）中的两个π态的幂律体积依赖性与QCD相同。 因此可以从混合作用模拟中提取无限体积下的散射参数。 然后我们在味同位旋极限下确定了2和2+1海夸克的散射长度。 当用格点上的π质量和衰变常数来表示散射长度时，没有来自混合价-海介子的贡献，因此它不依赖于出现在混合理论的手征Lagrangian中的参数C_Mix。 此外，当以这种形式写出散射长度时，名义上由混合作用O(a^2 mq) Lagrangian中的算符引起的贡献完全抵消。 这与用手征Lagrangian的裸参数表示的散射长度形成对比，后者明确展示了部分淬火混合作用理论允许的所有病态和晶格间距依赖性。 这些结果适用于2和2+1味海夸克的情况。 显示英文摘要

摘要： We calculate isospin 2 pion-pion scattering in chiral perturbation theory for a partially quenched, mixed action theory with Ginsparg-Wilson valence quarks and staggered sea quarks. We point out that for some scattering channels, the power-law volume dependence of two pion states in nonunitary theories such as partially quenched or mixed action QCD is identical to that of QCD. Thus one can extract infinite volume scattering parameters from mixed action simulations. We then determine the scattering length for both 2 and 2+1 sea quarks in the isospin limit. The scattering length, when expressed in terms of the pion mass and the decay constant measured on the lattice, has no contributions from mixed valence-sea mesons, thus it does not depend upon the parameter, C_Mix, that appears in the chiral Lagrangian of the mixed theory. In addition, the contributions which nominally arise from operators appearing in the mixed action O(a^2 m_q) Lagrangian exactly cancel when the scattering length is written in this form. This is in contrast to the scattering length expressed in terms of the bare parameters of the chiral Lagrangian, which explicitly exhibits all the sicknesses and lattice spacing dependence allowed by a partially quenched mixed action theory. These results hold for both 2 and 2+1 flavors of sea quarks.