3 research outputs found
Non-perturbative renormalisation of four fermion operators and B-bar B mixing with Wilson fermions
We present new results for the renormalisation and subtraction constants for
the four fermion Delta F=2 operators, computed non-perturbatively in the RI-MOM
scheme (in the Landau gauge). From our preliminary analysis of the lattice data
at beta=6.45, for the B-bar B mixing bag-parameter we obtain B_B^{RGI} =
1.46(7)(1).Comment: 3 pages (4 figures), Lattice2002(heavyquark
Kaon weak matrix elements with Wilson fermions
We present results of several numerical studies with Wilson fermions relevant for kaon physics. We compute the Bk parameter by using two different methods and extrapolate to the continuum limit. Our preliminary result is BKMS (2GeV) = 0.66 (7).ΔI = 3/2 K → ππ matrix elements (MEs) are obtained by using the next-to-leading order (NLO) expressions derived in chiral perturbation theory (ChPT) in which the low energy constants (LECs) are determined by the lattice results computed at unphysical kinematics. From the simulation at β = 6.0 our (preliminary) results read: ⟨gpπ O7¦MS¯ (2GeV)¦ K ⟩  I=2=0.14(1)(1) GeV3 and left angle bracketgp? O8¦MS¯(2GeV)¦Kright-pointing angle bracketI=2=0.69(6)(6)GeV3