Related papers: Twisted mass QCD and the $\Delta I=1/2$ rule
Lattice QCD simulations directly at physical masses of dynamical light, strange and charm quarks are highly desirable especially to remove systematic errors due to chiral extrapolations. However such simulations are still challenging. We…
Values for the strange quark mass and average up/down mass have been obtained from quenched lattice QCD simulations using the domain wall fermion action. This discretization preserves the properties of flavor and chiral symmetry at nonzero…
We investigate the thermal QCD phase transition and its scaling properties on the lattice. The simulations are performed with $N_f=2+1+1$ Wilson twisted mass fermions at pion masses from physical up to heavy quark regime. We introduce a…
The leading electromagnetic (e.m.) and strong isospin-breaking corrections to the $\pi^+ \to \mu^+ \nu[\gamma]$ and $K^+ \to \mu^+ \nu[\gamma]$ leptonic decay rates are evaluated for the first time on the lattice. The results are obtained…
An important tool for the analysis of results of numerical simulations of lattice QCD is chiral perturbation theory. In Wilson chiral perturbation theory the effects of the finite lattice spacing $a$ are taken into account. In recent years…
We propose a new method to evaluate the Lellouch-L\"uscher factor which relates the $\Delta I=3/2$ $K\to\pi\pi$ matrix elements computed on a finite lattice to the physical (infinite-volume) decay amplitudes. The method relies on the use of…
We present results of a lattice QCD application of a coordinate space renormalization scheme for the extraction of renormalization constants for flavour non-singlet bilinear quark operators. The method consists in the analysis of the…
We determine the strangeness and light quark fractions of the nucleon mass by computing the quark line connected and disconnected contributions to the matrix elements m_q <N|qbar q|N> in lattice QCD, using the non-perturbatively improved…
We present a high precision lattice calculation of the average up/down, strange and charm quark masses performed with Nf=2 twisted mass Wilson fermions. The analysis includes data at four values of the lattice spacing and pion masses as low…
We present a method to evaluate on the lattice the leading isospin breaking effects due to both the small mass difference between the up and down quarks and the QED interaction. Our proposal is applicable in principle to any QCD+QED gauge…
The twisted reduced model of large $N$ QCD with two adjoint Wilson fermions is studied numerically using the Hybrid Monte Carlo method. This is the one-site model, whose large $N$ limit (large volume limit) is expected to be conformal or…
We compute the complete supersymmetric QCD corrections to the Wilson coefficients of the magnetic and chromomagnetic operators, relevant in the calculation of b -> s gamma decays, in the MSSM with Minimal Flavor Violation. We investigate…
Our charm program uses a mixed action with twisted-mass valence quarks over non-perturbatively improved Wilson sea quarks, in order to study various quantities in a relativistic and manifestly local framework of full QCD. The sea sector…
It is possible to improve the chiral behaviour and the approach to the continuum limit of correlation functions in lattice QCD with standard and twisted Wilson fermions by taking arithmetic averages of correlators computed in theories…
Virtual quark pair screening leads to breaking of the string between fundamental representation quarks in QCD. For unquenched four dimensional lattice QCD, this (so far elusive) phenomenon is studied using the recently developed truncated…
We present, for the first time, an \textit{ab initio} calculation of the individual up, down and strange quark helicity parton distribution functions for the proton. The calculation is performed within the twisted mass clover-improved…
We present a calculation of the up, down, strange and charm quark masses performed within the lattice QCD framework. We use the twisted mass fermion action and carry out simulations that include in the sea two light mass-degenerate quarks,…
We present a strategy designed to separate several possible origins of the well-known enhancement of the Delta{I}=1/2 amplitude in non-leptonic kaon decays. In particular, we seek to disentangle the contribution of physics at the typical…
We review a relativistic approach to the heavy quark physics in lattice QCD by applying a relativistic $O(a)$ improvement to the massive Wilson quark action on the lattice. After explaining how power corrections of $m_Q a$ can be avoided…
I report on a study of finite temperature QCD by the CP-PACS Collaboration toward a precise determination of the equation of state with dynamical u,d quarks. Based on a systematic simulation using improved Wilson-type quarks on lattices…