0000000001019158
AUTHOR
D. Becirevic
showing 8 related works from this author
B parameters of the complete set of matrix elements of delta B = 2 operators from the lattice
2001
We compute on the lattice the ``bag'' parameters of the five (Delta B = 2) operators of the supersymmetric basis, by combining their values determined in full QCD and in the static limit of HQET. The extrapolation of the QCD results from the accessible heavy-light meson masses to the B-meson mass is constrained by the static result. The matching of the corresponding results in HQET and in QCD is for the first time made at NLO accuracy in the MSbar(NDR) renormalization scheme. All results are obtained in the quenched approximation.
Non-perturbative renormalisation of four fermion operators and B0 −B0 bar mixing with Wilson fermions
2003
We present new results for the renormalisation and subtraction constants for the four fermion DeltaF = 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-0 - B-0,mixing bag-parameter we obtain B-B(RGI) = 1.46(7)(1).
Combined relativistic and static analysis for all DB = 2 operators
2001
We analyse matrix elements of Delta B=2 operators by combining QCD results with the ones obtained in the static limit of HQET. The matching of all the QCD operators to HQET is made at NLO order. To do that we have to include the anomalous dimension matrix up to two loops, both in QCD and HQET, and the one loop matching for all the Delta B=2 operators. The matrix elements of these operators are relevant for the prediction of the B-\bar B mixing, B_s meson width difference and supersymmetric effects in Delta B=2 transitions.
Matrix elements of (delta S=2) operators with Wilson fermions
2002
We test the recent proposal of using the Ward identities to compute the K0-K0bar mixing amplitude with Wilson fermions, without the problem of spurious lattice subtractions. From our simulations, we observe no difference between the results obtained with and without subtractions. In addition, from the standard study of the complete set of (delta S=2) operators, we quote the following (preliminary) results (in the MS(NDR) scheme): Bk(2 GeV)=0.70(10), < O7^{3/2}>_{K->pi pi} = 0.10(2)(1) GeV^3, < O8^{3/2}>_{K->pi pi} = 0.49(6)(0) GeV^3.
Non-perturbatively renormalised light quark masses from a lattice simulation with N(f) = 2
2006
We present results for the light quark masses obtained from a lattice QCD simulation with N-f = 2 degenerate Wilson dynamical quark flavours. The sea quark masses of our lattice, of spacing a similar or equal to 0.06 fm, are relatively heavy, i.e., they cover the range corresponding to 0.60 less than or similar to M-p/M-V less than or similar to 0.75. After implementing the non-perturbative RI-MOM method to renormalise quark masses, we obtain m(ud)((MS) over bar)(2 GeV)= 4.3 +/- 0.4(-0)(+1.1) MeV, and m(s)((MS) over bar)(2 GeV) = 101 +/- 8(-0)(+25) MeV, which are about 15% larger than they would be if renormalised perturbatively. In addition, we show that the above results are compatible wi…
K-0-(K)over-bar(0) mixing with Wilson fermions without subtractions
2000
By using suitable Ward identities, we show that it is possible to compute K-0-(K) over bar(0) mixing without subtracting the terms generated by explicit chiral symmetry breaking present in Wilson-like lattice actions. The accuracy in the determination of the amplitudes is of O(a), which is the best one attainable in the absence of improvement.
The CKM Matrix and the Unitarity Triangle
2003
This report contains the results of the Workshop on the CKM Unitarity Triangle, held at CERN on 13-16 February 2002 to study the determination of the CKM matrix from the available data of K, D, and B physics. This is a coherent document with chapters covering the determination of CKM elements from tree level decays and K and B meson mixing and the global fits of the unitarity triangle parameters. The impact of future measurements is also discussed.
B(d) - anti-B(d) mixing and the B(d) ---> J / psi K(s) asymmetry in general SUSY models
2002
We present a next-to-leading order determination of the gluino-mediated SUSY contributions to B-d-(B) over bard mixing and to the CP asymmetry a(J)/psiK(s) in the framework of the mass-insertion approximation. Using hadronic matrix elements recently computed on the lattice, we obtain improved constraints on the squark-mass splittings.