Related papers: Electromagnetic and Mass Difference Corrections in…
We use the Cottingham method to calculate the pion and kaon electromagnetic mass differences with as few model dependent inputs as possible. The constraints of chiral symmetry at low energy, QCD at high energy and experimental data in…
We calculate isospin breaking in pion-nucleon scattering in the threshold region in the framework of covariant baryon chiral perturbation theory. All effects due to quark mass differences as well as real and virtual photons are consistently…
We investigate isospin breaking in low-energy pion-nucleon scattering in the framework of chiral perturbation theory. This work extends the systematic analysis of [1] to the energy range above threshold. Various relations, which identically…
It is shown that isospin-breaking corrections to the pion-deuteron scattering length can be very large, because of the vanishing of the isospin-symmetric contribution to this scattering length at leading order in chiral perturbation theory.…
I discuss low-energy pion-nucleon scattering in the framework of chiral perturbation theory. I argue that using this theoretical method one is able to handle the in some cases tremendous experimental accuracy (for the low partial waves). I…
We discuss the electromagnetic corrections to the pion-nucleon scattering lengths generated by minimal e. m. coupling from a knowledge of the low energy expansion of the pion-nucleon elastic scattering amplitude as well as from the nucleon…
We compute the electromagnetic mass difference for the $B$-, $D$- and $K$-mesons using QCD sum rules with double dispersion relations. For the $B$- and $D$-mesons we also compute the linear quark mass correction, whereas for the $K$ the…
We compute low temperature corrections to the electromagnetic mass difference of pions in the chiral limit. The computation is done in a model independent way in the framework of chiral perturbation theory, using the background field method…
We report on the calculation by the MILC Collaboration of the electromagnetic effects on kaon and pion masses. These masses are computed in QCD with dynamical (asqtad staggered) quarks plus quenched photons at three lattice spacings varying…
The electromagnetic corrections to the low energy scattering amplitude involving charged pions only are investigated at leading and next-to-leading orders in the two-flavour chiral expansion. As an application, the corresponding variation…
We calculate the electromagnetic corrections to the isospin invariant mixing angle and to the two eigenphases for the $s$-, $p_{1/2}$- and $p_{3/2}$-partial waves for $\pi^- p$ elastic and charge exchange scattering. These corrections have…
We analyze isospin breaking through quark mass differences and virtual photons in the pion-nucleon scattering lengths in all physical channels in the framework of covariant baryon chiral perturbation theory. The so-called triangle relation…
We calculate the electromagnetic corrections to the isospin invariant mixing angle and to the two eigenphases for the s and p-waves for low energy pi-p elastic and charge exchange scattering. These corrections have to be applied to the…
Electromagnetic corrections to the low-energy pi+ pi- -> pi0 pi0 scattering amplitude at next-to-leading order in the chiral expansion are reviewed. Their effects on the corresponding scattering lengths are estimated and compared to the…
Elastic pion-pion and pion-nucleon scattering are reviewed in the context of chiral perturbation theory. Theoretical results from systematic low-energy expansions to O(p^6) for pion-pion and to O(p^3) for pion-nucleon scattering are…
We calculate the electromagnetic corrections needed to obtain isospin invariant hadronic pion-pion s-wave scattering lengths a^0, a^2 from the elements a_cc, a_0c of the s-wave scattering matrix for the (\pi^+ \pi^-, \pi^0 \pi^0) system at…
We evaluate the isospin breaking corrections to the scattering amplitude \pi^- K^+ -> \pi^- K^+ at threshold in the framework of chiral perturbation theory. This channel is of particular interest for the strong 2S-2P energy level shift in…
We investigate theoretical approaches to pion--nucleus elastic scattering at high energies (300 $\le T_\pi \le$ 1 GeV). A ``model--exact'' calculation of the lowest--order microscopic optical model, carried out in momentum space and…
We consider pion-nucleon scattering in heavy-baryon chiral perturbation theory to third order. All electromagnetic corrections appearing to this order are included. We thus have a consistent description of strong and electromagnetic…
I discuss recent progress made in calculating electromagnetic corrections in the framework of the effective field theory of QCD. In the case of elastic pion-pion scattering, strong interaction predictions have been worked out to two loop…