Related papers: Electromagnetic contributions to pseudoscalar mass…
We use the observed $SU(3)$ breaking in the mass spectrum of mesons containing a single heavy quark to place restrictions on the light quark current masses. A crucial ingredient in this analysis is our recent first-principles calculation of…
This work discusses reliability, possible obstacles and the future perspective of chiral extrapolation of lattice results. In the first part, chiral perturbation theory fits to lattice calculations of the nucleon mass are thoroughly…
We investigate the nucleon self energy through the sixth chiral order in the covariant $SU(2)$ chiral perturbation theory ($\chi$PT) in the single baryon sector. The validity of the extended on-mass-shell (EOMS) renormalization scheme is…
We investigate electromagnetic effects in the framework of chiral perturbation theory. Using a completely independent method, we confirm Urech's results for the divergences of the one--loop functional in the electromagnetic sector. We…
A SU(2) effective lagrangian is extended to a $SU_{L}(3)\otimes SU_{R}(3)$ by including the vector and axial vector meson. With this effective lagrangian, electromagnetic form factors of charged pion and kaon are calculated. The…
We summarise status and recent results of the European Twisted Mass collaboration (ETMC). The collaboration has generated gauge configurations for three different values of the lattice spacing smaller or equal 0.1 fm and values of the…
We outline the modified formulation of baryon chiral effective field theory for nucleon-nucleon scattering and discuss the issue of a possible power counting violation by the nucleon mass. We also present the results for the quark mass…
We present for the first time the nonlinear dynamics of quantum electrodynamic (QED) photon splitting in a strongly magnetized electron-positron (pair) plasma. By using a QED corrected Maxwell equation, we derive a set of equations that…
Standard methods for including electromagnetic interactions in lattice quantum chromodynamics calculations result in power-law finite-volume corrections to physical quantities. Removing these by extrapolation requires costly computations at…
We present lattice QCD calculations of nucleon electromagnetic form factors using pion masses $m_\pi$ = 149, 202, and 254 MeV and an action with clover-improved Wilson quarks coupled to smeared gauge fields, as used by the…
We calculate the nucleons' electromagnetic polarizabilities in heavy baryon chiral perturbation theory including all terms to order ${\cal O} (q^4)$. The chiral prediction of the electric polarizabilities for the neutron and the proton are…
Kaon in-medium masses and mean-field potentials are calculated in isotopically symmetric pion matter to one loop of chiral perturbation theory. The results are extended to RHIC temperatures using experimental data on $\pi K$ scattering…
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…
We calculate the finite volume effects for the pion and nucleon mass. For the pion mass we present the results of a full two-loop calculation in chiral perturbation theory. The outcome shows that the resummed version of the Luscher formula…
We present a calculation of the electromagnetic form factor of the pion in $N_f=2+1$ flavor lattice QCD. Calculations are made on the PACS-CS gauge field configurations generated using Iwasaki gauge action and Wilson-clover quark action on…
We present the latest preliminary results of the MILC collaboration's analysis of the light pseudoscalar meson sector. The analysis includes data from new ensembles with smaller lattice spacings, smaller light quark masses and…
We study light-quark observables by means of dynamical lattice QCD simulations using two flavours of twisted mass fermions at maximal twist. We employ chiral perturbation theory to describe our data for the pion mass and decay constant. In…
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 investigate the self-energies of particles in an external magnetic field $B$. The dependence is generally of the type $\sqrt{P(B)}$ with $P$ a polynomial in $B$ and the participating masses. The non-analytic point depends on the mass and…
We present the first computation in a program of lattice-QCD baryon physics using staggered fermions for sea and valence quarks. For this initial study, we present a calculation of the nucleon mass, obtaining $964\pm16$ MeV with all sources…