We present a lattice QCD determination of the chiral quark condensate based on a new method. We extract the quark condensate from the operator product expansion of the quark propagator at short ...euclidean distances, where it represents the leading contribution in the chiral limit. From this study we obtain \({\left\langle {\bar{q}q} \right\rangle }^{{\overline{{{\text{MS}}} }} {\left( {2\;{\text{GeV}}} \right)} = - {\left( {265 \pm 5 \pm 22\;{\text{MeV}}} \right)}^{3} \), in good agreement with determinations of this quantity based on different approaches. The simulation is performed by using the \({\cal O}(a)\)-improved Wilson action at\(\beta = 6.45\)on a volume 323 × 70 in the quenched approximation.
Combining the recent experimental evidence of D–D¯ mixing, we extract model-independent information on the mixing amplitude and on its CP-violating phase. Using this information, we present new ...constraints on the flavour structure of up-type squark mass matrices in supersymmetric extensions of the Standard Model.
PoS LAT2005 (2005) 081 We perform an exploratory study of the operator product expansion of the
quark propagator on the lattice at short distance in coordinate space. This
permits a simple ...determination of the quark condensate, ^MS(2 GeV)=(-265\pm
5\pm 22 MeV)^3, and of the renormalization constant of the quark field, Z^MS(2
GeV)=0.871 \pm 0.003 \pm 0.020. This new method also provides a remarkable
non-perturbative test of the OPE predictions at short distance in QCD.
Eur.Phys.J.C41:535-544,2005 We present a Lattice QCD determination of the chiral quark condensate based
on a new method. We extract the quark condensate from the operator product
expansion of the ...quark propagator at short euclidean distances, where it
represents the leading contribution in the chiral limit. From this study we
obtain <\bar q q>^ms(2 GeV)=-(265+-5+-22 MeV)^3$, in good agreement with
determinations of this quantity based on different approaches. The simulation
is performed by using the O(a)-improved Wilson action at beta=6.45 on a volume
32^3\times70 in the quenched approximation.
Phys.Lett.B655:162-166,2007 Combining the recently available experimental evidence of D-Dbar mixing, we
extract model-independent information on the mixing amplitude and on its
CP-violating phase. ...Using this information, we present new constraints on the
flavour structure of up-type squark mass matrices in supersymmetric extensions
of the Standard Model.
JHEP 0609:013,2006 We compute the next-to-leading order strong interaction corrections to
gluino-mediated Delta F=2 box diagrams in the Minimal Supersymmetric Standard
Model. These corrections are ...given by two loop diagrams which we have
calculated in three different regularization schemes in the mass insertion
approximation. We obtain the next-to-leading order Wilson coefficients of the
Delta F=2 effective Hamiltonian relevant for neutral meson mixings. We find
that the matching scale uncertainty is largely reduced at the next-to-leading
order, typically from about 10-15% to few percent.
We present the NLO corrections to the Wilson coefficients of the Delta F = 2
Hamiltonians in the strong interacting sector of the MSSM, responsible for
neutral meson oscillations. Such corrections, ...combined with the NLO anomalous
dimension matrix for the Delta F = 2 operators and the corresponding hadronic
matrix elements calculated on the lattice, allow for the first time a full NLO
phenomenological analysis of the observables related to meson oscillations. We
present preliminary results in the B_d - B_d bar sector.
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