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V. Porretti

Publications and source records attributed to V. Porretti.

7 recordsLinked to original sources
arXiv2008

Flavour physics of leptons and dipole moments

This chapter of the report of the ``Flavour in the era of the LHC'' Workshop discusses the theoretical, phenomenological and experimental issues related to flavour phenomena in the charged lepton sector and in flavour-conserving CP-violating processes. We review the current experimental limits and the main theoretical models for the flavour structure of fundamental particles. We analyze the phenomenological consequences of the available data, setting constraints on explicit models beyond the Standard Model, presenting benchmarks for the discovery potential of forthcoming measurements both at the LHC and at low energy, and exploring options for possible future experiments.

hep-ph↗
arXiv2007

D-Dbar mixing and new physics: general considerations and constraints on the MSSM

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.

hep-ph↗
arXiv2006

Next-to-leading order strong interaction corrections to the Delta F=2 effective Hamiltonian in the MSSM

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.

hep-ph↗
arXiv2005

NLO calculation of the Delta F = 2 Hamiltonians in the MSSM and phenomenological analysis of the B - Bbar mixing

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.

hep-ph↗
arXiv2005

Operator product expansion and quark condensate from LQCD in coordinate space

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.

hep-lat↗
arXiv2005

Operator product expansion and quark condensate from Lattice QCD in coordinate space

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.

hep-lat↗