We present unquenched lattice QCD results for the matrix elements of four-fermion operators relevant to the description of the neutral K and D mixing in the standard model and its extensions. We have employed simulations with Nf=2+1+1 dynamical sea quarks at three values of the lattice spacings in the interval 0.06-0.09 fm and pseudoscalar meson masses in the range 210-450 MeV. Our results are extrapolated to the continuum limit and to the physical pion mass. Renormalization constants have been determined nonperturbatively in the RI-MOM scheme. In particular, for the kaon bag parameter, which is relevant for the K¯0-K0 mixing in the standard model, we obtain BKRGI=0.717(24).
|Titolo:||ΔS=2 and ΔC=2 bag parameters in the standard model and beyond from Nf=2+1+1 twisted-mass lattice QCD|
|Data di pubblicazione:||2015|
|Citazione:||Carrasco, N., Dimopoulos, P., Frezzotti, R., LUBICZ, V., Rossi, G.C., SIMULA, S., et al. (2015). ΔS=2 and ΔC=2 bag parameters in the standard model and beyond from Nf=2+1+1 twisted-mass lattice QCD. PHYSICAL REVIEW D, PARTICLES, FIELDS, GRAVITATION, AND COSMOLOGY, 92(3).|
|Appare nelle tipologie:||1.1 Articolo in rivista|