8 research outputs found
Lattice QCD study of decay near zero recoil
We study the hadronic matrix elements describing the decay in and beyond the Standard Model. By using the twisted mass
QCD on the lattice with dynamical flavors we compute the normalization
of the form factor dominating
in the SM. We also make the first lattice determination of
and near zero recoil (near ). We briefly
discuss the non-strange case as well.Comment: presented at the 31st International Symposium on Lattice Field Theory
(Lattice 2013), 29 July - 3 August 2013, Mainz, German
Renormalization constants for twisted mass QCD
We summarize recent non-perturbative results obtained for the renormalization
constants computed in the RI'-MOM scheme for twisted mass
QCD. Our implementation employs the Iwasaki gauge action and four dynamical
degenerate twisted mass fermions. Renormalization constants for scalar,
pseudo-scalar, vector and axial operators, as well as the quark propagator
renormalization, are computed at three different values of the lattice spacing,
two different volumes and several values of the twisted mass. Our method allows
for a precise cross-check of the running, because of the particular proper
treatment of the hypercubic artifacts. Preliminary results for twist-2
operators are also presented
Renormalization of quark propagator, vertex functions and twist-2 operators from twisted-mass lattice QCD at =4
We present a precise non-perturbative determination of the renormalization
constants in the mass independent RI'-MOM scheme. The lattice implementation
uses the Iwasaki gauge action and four degenerate dynamical twisted mass
fermions. The gauge configurations are provided by the ETM Collaboration.
Renormalization constants for scalar, pseudo-scalar, vector and axial
operators, as well as the quark propagator renormalization, are computed at
three different values of the lattice spacing, two volumes and several twisted
mass parameters. The method we developed allows for a precise cross-check of
the running, thanks to the particular proper treatment of hypercubic artifacts.
Results for the twist-2 operator are also presented.Comment: 20 pages, 20 figures, submitted to Phys. Rev.
Some hadronic parameters of charmonia in lattice QCD
International audienceThe phenomenology of leptonic decays of quarkonia holds many interesting features: for instance, it can establish constraints on scenarios beyond the Standard Model with the Higgs sector enriched by a light CP-odd state. In the following paper, we report on a two-flavor lattice QCD study of the and decay constants, and . We also examine some properties of the first radial excitation and
On the D*s and charmonia leptonic decays
Among the different scenarios of New Physics, those with an extended Higgs sector are examined with a lot of attention. Recent experimental observations of several anomalies in flavour physics with respect to expectations of the Standard Model further motivate the effort of phenomenologists. First, informations about the RDs ratio, a test of lepton flavour universality equivalent to RD, already measured, but with the s quark as spectator, are awaited in coming years to constrain the corner of an extended Higgs sector with charged doublets. On another side, leptonic widths of pseudoscalar quarkonia are particularly interesting to test an extended Higgs sector with a light CP-odd Higgs boson singlet, through the study of its mixing with quarkonia states. Hadronic parameters entering those processes have to be determined from lattice QCD with enough confidence on the control of systematic errors. We report on the very first step of a long-term program tackled with Nf = 2 Wilson-Clover fermions to put relevant constraints on extensions of the Higgs sector: extraction of decay constants of D*s, ƞc, ƞc (2S), J/Ψ and Ψ(2S) with lattice ensembles provided by the CLS effort, considering 2 lattice spacings and a large range of pion masses to estimate cut-off effects and extrapolate results to the chiral limit
On the
Among the different scenarios of New Physics, those with an extended Higgs sector are examined with a lot of attention. Recent experimental observations of several anomalies in flavour physics with respect to expectations of the Standard Model further motivate the effort of phenomenologists. First, informations about the RDs ratio, a test of lepton flavour universality equivalent to RD, already measured, but with the s quark as spectator, are awaited in coming years to constrain the corner of an extended Higgs sector with charged doublets. On another side, leptonic widths of pseudoscalar quarkonia are particularly interesting to test an extended Higgs sector with a light CP-odd Higgs boson singlet, through the study of its mixing with quarkonia states. Hadronic parameters entering those processes have to be determined from lattice QCD with enough confidence on the control of systematic errors. We report on the very first step of a long-term program tackled with Nf = 2 Wilson-Clover fermions to put relevant constraints on extensions of the Higgs sector: extraction of decay constants of D*s, ƞc, ƞc (2S), J/Ψ and Ψ(2S) with lattice ensembles provided by the CLS effort, considering 2 lattice spacings and a large range of pion masses to estimate cut-off effects and extrapolate results to the chiral limit