2010/09/30 by ETM Collaboration, Martha Constantinou, M. Constantinou +19
Physics and Astronomy · #Black Holes and Theoretical Physics #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-lat #hep-ph
paper · pdf · doi:10.1103/physrevd.83.014505
published as Phys.Rev.D83:014505,2011 · Accepted for publication in Phys. Rev. D; systematic error discussion slightly modified; total uncertainty estimate on the BK result unchanged; 42 pages, 25 figures
arxiv created 2011/01/07 · openalex publication_date 2011/01/11 · arxiv updated 2011/02/03 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/04
We present an unquenched Nf=2 lattice computation of the BK parameter which controls K0\ensuremath-K0 oscillations. A partially quenched setup is employed with two maximally twisted dynamical (sea) light Wilson quarks, and valence quarks of both the maximally twisted and the Osterwalder-Seiler variety. Suitable combinations of these two kinds of valence quarks lead to a lattice definition of the BK parameter which is both multiplicatively renormalizable and O(a) improved. Employing the nonperturbative RI-MOM scheme, in the continuum limit and at the physical value of the pion mass we get BKRGI=0.729\ifmmode±\else\textpm\fi0.030, a number well in line with the existing quenched and unquenched determinations.