Chiral perturbation theory for staggered sea quarks and Ginsparg-Wilson valence quarks

Abstract

We study lattice QCD with staggered sea and Ginsparg-Wilson valence quarks. The Symanzik effective action for this mixed lattice theory, including the lattice spacing contributions of O(a 2 ), is derived. Using this effective theory we construct the leading order chiral Lagrangian. The masses and decay constants of pseudoscalars containing two Ginsparg-Wilson valence quarks are computed at one loop order.

Taste violations in the scalar correlator in mixed action simulations

“…where ∆ mix is a new splitting, unique to the particular choice of mixed action, that arises from fourquark operators in the same way as the staggered taste splittings arise [9]. Although this parameter does not appear in many mixed action quantities (such as m 2 π or B K ), it will play an important role in f K and also the scalar correlator.…”

“…[9] in the context of m π , f π , and has been extended for many other quantities. Although we will not describe mixedaction χ PT in detail, we would like to look at the three different types of mesons that can arise: those made from two sea quarks, those from two valence quarks, and finally mesons with one of each type of quark.…”

Status of Kaon physics on the lattice

“…New developments: Aubin, Laiho and Van de Water [89] developed the partially quenched chiral perturbation theory for domain wall valence fermions combined with AsqTad staggered sea quarks. In this mixed action ansatz [90] the symmetry properties of the domain wall valence quarks protects the B K -operator from mixing with operators of non-trivial taste structure. Compared to continuum partially quenched chiral perturbation theory [75] there are only two additional parameters.…”

Double poles in Lattice QCD with mixed actions

“…(9) is of order ǫ 3 × (ML) 3 and ǫ 2 × ML for the δ 2 , respectively, δǫ terms. In the second regime this ratio is of order ǫ × (ML) 3 .…”