P. Dimopoulos

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We present results of dynamical simulations of N f = 2 degenerate Wilson twisted mass quarks at maximal twist in the range of pseudo scalar masses 300 MeV m PS 550 MeV. Reaching such small masses was made possible owing to a recently developed variant of the HMC algorithm. The simulations are performed at one value of the lattice spacing a 0.1 fm. In order(More)
In a recent paper [1] we presented precise lattice QCD results of our Eu-ropean Twisted Mass Collaboration (ETMC). They were obtained by employing two mass-degenerate flavours of twisted mass fermions at maximal twist. In the present paper we give details on our simulations and the computation of physical observables. In particular, we discuss the problem(More)
We present the results of a lattice QCD calculation of the average up-down and strange quark masses and of the light meson pseudoscalar decay constants with N f = 2 dynamical fermions. The simulation is carried out at a single value of the lattice spacing with the twisted mass fermionic action at maximal twist, which guarantees automatic O(a)-improvement of(More)
We study a 4+1 dimensional pure Abelian Gauge model on the lattice with two anisotropic couplings independent of each other and of the coordinates. A first exploration of the phase diagram using mean field approximation and monte carlo techniques has demonstrated the existence of a new phase, the so called Layer phase, in which the forces in the 4–D(More)
We present an update of the results for pion mass and pion decay constant as obtained by the ETM collaboration in large scale simulations with maximally twisted mass fermions and two mass degenerate flavours of light quarks. We discuss the continuum, chiral and infinite volume extrapolation of these quantities as well as the extraction of low energy(More)
We present results for the renormalisation constants of bilinear quark operators, using the N f = 2 twisted mass Wilson action at maximal twist (which guarantees automatic O(a) improvement) and the tree-level Symanzik improved gauge action. The scale-independent renormalisation constants are computed with a new method, which makes use of both standard(More)
We apply finite-size recursion techniques based on the Schrödinger functional formalism to determine the renormalization group running of four-fermion operators which appear in the ∆S = 2 effective weak Hamiltonian of the Standard Model. Our calculations are done using O(a) improved Wilson fermions with N f = 2 dynamical flavours. Preliminary results are(More)
We explore the phase diagram of the five-dimensional anisotropic Abelian Higgs model by Monte Carlo simulations. In particular, we study the transition between the confining phase and the four dimensional layered Higgs phase. We find that, in a certain region of the lattice parameter space, this transition can be first order and that each layer moves into(More)
We establish the phase diagram of the five-dimensional anisotropic Abelian Higgs model by mean field techniques and Monte Carlo simulations. The anisotropy is encoded in the gauge couplings as well as in the Higgs couplings. In addition to the usual bulk phases (confining, Coulomb and Higgs) we find four-dimensional " layered " phases (3-branes) at weak(More)