B_K with two flavors of dynamical overlap fermions

Abstract

We present a two-flavor QCD calculation of $B_K$ on a $16^3\times 32$ lattice at $a\sim 0.12$ fm (or equivalently $a^{-1}\sim$1.67 GeV). Both valence and sea quarks are described by the overlap fermion formulation. The matching factor is calculated non-perturbatively with the so-called RI/MOM scheme. We find that the lattice data are well described by the next-to-leading order (NLO) partially quenched chiral perturbation theory (PQChPT) up to around a half of the strange quark mass ($m_s^{\mathrm{phys}}/2$). The data at quark masses heavier than $m_s^{\mathrm{phys}}/2$ are fitted including a part of next-to-next-to-leading order terms. We obtain $B_K^{\overline{\mathrm{MS}}}(2\mathrm{GeV})=0.537(4)(40)$, where the first error is statistical and the second is an estimate of systematic uncertainties from finite volume, fixing topology, the matching factor, and the scale setting.

36 pages, 14 figures, comments and references added, analysis and systematic error revised, minor change in the final result. version to appear in PRD, reference corrected

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Cited by in corpus (22)

• FLAG Review 2019
• Review of lattice results concerning low energy particle physics
• Flavor Physics in the Quark Sector
• Anatomy of New Physics in B-Bbar mixing
• Correlations among new CP violating effects in Delta F = 2 observables
• Possible evidence for the breakdown of the CKM-paradigm of CP-violation
• Continuum Limit of $B_K$ from 2+1 Flavor Domain Wall QCD
• Pion form factors from two-flavor lattice QCD with exact chiral symmetry
• $B_K$ using HYP-smeared staggered fermions in $N_f=2+1$ unquenched QCD
• Nucleon strange quark content from two-flavor lattice QCD with exact chiral symmetry
• BK-parameter from Nf = 2 twisted mass lattice QCD
• On the consistency between the observed amount of CP violation in the K- and Bd-systems within minimal flavor violation
• Natural SUSY and Kaon Mixing in view of recent results from Lattice QCD
• Kaon physics: a lattice perspective
• $K_{l3}$ form factors at the physical point on (10.9 fm)${}^3$ volume
• $K_{\ell 3}$ form factors at the physical point: Toward the continuum limit
• Recent Progress in Lattice QCD
• Review: The FLAG working group
• Physics results from dynamical overlap fermion simulations
• Phenomenology from the Lattice
• Lattice Kaon Physics
• Spontaneous chiral symmetry breaking on the lattice