Related papers: Anomalous processes and leading logarithms
We add the Wess-Zumino-Witten term to the N=3 massive nonlinear sigma model and study the leading logarithms in the anomalous sector. We obtain the leading logarithms to six loops for \pi^0 --> \gamma^*\gamma^* and to five loops for…
The thermodynamics of quantum chromodynamics at low temperatures and in sufficiently strong magnetic fields is governed by neutral pions. We analyze the interacting system of neutral pions and photons at zero baryon chemical potential using…
Two-photon decays probe the structure of mesons and represent an important contribution to hadronic light-by-light scattering. For the neutral pion, the decay amplitude tests the effects of the chiral anomaly; for a heavy quarkonium state,…
An implicit four dimensional regularization is applied to calculate the axial-vector-vector anomalous amplitude. The present technique always complies with results of Dimensional Regularization and can be easily applied to processes…
We show that a simple and reasonable generalization of the anomalous interaction between the neutral pion and two photons can induce the C-violating three photon decay of the neutral pion in noncommutative quantum electrodynamics. We find…
A systematic study of the odd-intrinsic parity sector of QCD is presented. We briefly describe different applications including pi0 -> gamma gamma decay, muonic (g-2) factor and a test of the new holographic conjectures.
We discuss insights that may be drawn from our recent 2 flavour O(a)--improved Wilson quark simulations. We discuss the evidence of the onset of chiral logarithms in the pion decay constant. An overview is given of current extrapolation…
The QCD structure of the electron is defined and calculated. The leading order splitting functions are extracted, showing an important contribution from $\gamma$-$Z$ interference. Leading logarithmic QCD evolution equations are constructed…
By matching 1/m^2 divergences in finite-volume two-point correlation functions of the scalar or pseudoscalar densities with those obtained in chiral perturbation theory, we derive a relation between the Dirac operator zero-mode…
The hadronic light-by-light contribution to a_{mu}, the anomalous magnetic moment of the muon, is discussed from the point of view of an effective low-energy theory. As an application, the coefficient of the leading logarithm arising from…
In these lectures I first cover radiative and semileptonic B decays, including the QCD corrections for the quark subprocesses. The exclusive modes and the evaluation of the hadronic matrix elements, i.e. the relevant hadronic form factors,…
We generalize the next-to-leading order QCD calculations for the decay rates of $h\to gg$ and $h\to\gamma\gamma$ to the case of anomalous couplings of the Higgs boson. We demonstrate how this computation can be done in a consistent way…
A simple matching procedure is proposed to extract constraints on effective meson theories. In this way, a QCD prediction for the pion decay constant is found, F(pi)=2 m(pi)/pi, i.e. approximately 90MeV. The same procedure also determines…
Recent progress in using effective field theory to describe systems with two nucleons is discussed with particular emphasis placed on the inclusion of pions. Inconsistencies arising in Weinberg's power counting are demonstrated with two…
The leading order contributions of processes involving anomalous pion-photon vertices to forward spin-dependent Compton scattering from nucleons are considered in heavy-baryon chiral perturbation theory. These all involve the exchange of…
An explicit expression of the generating functional of two-flavor low-energy QCD with external sources in the presence of non-vanishing nucleon densities has been derived recently [1]. Within this approach we derive power counting rules for…
This talk describes the work done in calculating leading logarithms in massive effective field theories. We discuss shortly leading logarithms in renormalizable theories and how they can be calculated using only one-loop calculations in…
I report on three recent topics from the field of two-body nonleptonic decays of $B_{(s)}$ mesons. The computation of two-loop NNLO corrections to the leading penguin amplitudes in QCD factorisation, puzzles that have emerged in…
We analyse the most general odd-intrinsic-parity effective Lagrangian of QCD valid for processes involving one pseudoscalar with vector mesons described in terms of antisymmetric tensor fields. Substantial information on the…
We present a study of two-photon decays of light mesons, focusing on the neutral pion decay. This important process highlights the effects of the axial anomaly in QCD but has been little studied on the lattice. By applying the…