2006/03/27 by E. Gámiz, E. Gamiz, S. Collins +7 · 1 citation
Mathematics · Physics and Astronomy · #Degenerate energy levels #Extrapolation #Fermion #High-Energy Particle Collisions Research #Lattice (music) #Mathematics #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #Quantum mechanics #Quark #Statistics #Strange quark #Unitarity #Valence (chemistry) #hep-lat #hep-ph
paper · pdf · doi:10.1103/physrevd.73.114502
published as Phys.Rev.D73:114502,2006 · 15 pages, 6 figures
arxiv created 2006/03/27 · openalex publication_date 2006/06/09 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The use of improved staggered actions (HYP, Asqtad) has been proved to reduce the scaling corrections that affected previous calculations of BK with unimproved (standard) staggered fermions in the quenched approximation. This improved behavior allows us to perform a reliable calculation of BK including quark vacuum polarization effects, using the MILC configurations with nf=2+1 flavors of sea fermions. We perform such a calculation for a single lattice spacing, a=0.125 fm, and with kaons made up of degenerate quarks with ms/2. The valence strange quark mass ms is fixed to its physical value and we use two different values of the light sea quark masses. After a chiral extrapolation of the results to the physical value of the sea quark masses, we find \stackrel^BK=0.83\ifmmode±\else\textpm\fi0.18, where the error is dominated by the uncertainty in the lattice to continuum matching at O(\ensuremathαs2). The matching will need to be improved to get the precision needed to make full use of the experimental data on \ensuremathεK to constrain the unitarity triangle.