Related papers: Chiral loop corrections and isospin violation effe…
An isospin analysis of $B\to \pi\pi$ decays yields $\sin 2\alpha$, where $\alpha$ is the usual CKM angle $\alpha\equiv {\rm arg} [-V_{td} V_{tb}^\ast/(V_{ud}V_{ub}^\ast)]$ without hadronic uncertainty if isospin is a perfect symmetry. Yet…
We make use of the chiral two-loop representation of the pi K scattering amplitude [J. Bijnens, P. Dhonte and P. Talavera, JHEP 0405 (2004) 036] to investigate the isospin odd scattering length at next-to-next-to-leading order in the SU(3)…
We calculate the direct $CP$ violation for the decay process of ${B}^{0}\rightarrow \pi^{0}\pi^{0}$, ${B}^{+}\rightarrow \pi^{0}\pi^{+}$, ${B}^{0}\rightarrow K^{0}\pi^{0}$ and ${B}^{+}\rightarrow K^{+}\pi^{0}$ via isospin symmetry breaking…
We report on a calculation of $\epsilon_K'/\epsilon_K$ at next-to-leading in the $1/N_c$ expansion and to lowest order in Chiral Perturbation Theory. We discuss the short-distance matching, the scale and scheme dependence as well as the…
After updating the determination of the combination of Kobayashi-Maskawa elements $ \Im V_{td}V^*_{ts}$ according to our new estimate of the parameter $\hat B_K$, we study the CP-violating ratio $\epsilon'/\epsilon$ by means of hadronic…
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…
The measurement of epsilon'/epsilon has left open several theoretical problems, the most important of which is an accurate calculation of the relevant hadronic matrix elements. Here we study the possibility of relating epsilon' to CP…
We pursue the calculation of the model-independent component of the axion-photon-photon coupling in the $U(3)$ chiral perturbation theory up to next-to-leading order, with the emphasis on the isospin breaking effect. The mixing of the…
We investigate the direct $CP$ violation for the decay process of $\bar{B}_{s}\rightarrow P(V)\pi^{0}$ (P,V refer to the pseudoscalar meson and vector meson, respectively) via isospin symmetry breaking effects from the $\pi^{0}-\eta-\eta'$…
We construct the complete effective chiral pion-nucleon Lagrangian in the presence of virtual photons to one loop. As an application, we consider strong and electromagnetic isospin violation for scattering of neutral pions off nucleons. We…
We study the impact of explicit chiral symmetry breaking of lattice Wilson fermions on mesonic correlators in the epsilon-regime using Wilson chiral perturbation theory. We generalize the epsilon-expansion of continuum chiral perturbation…
The K to pi pi system is analyzed in the chiral limit and at NLO in 1/N_c. The Delta I = 1/2 rule is reproduced and we obtain a large value for epsilon' / epsilon.
We study the impact of explicit chiral symmetry breaking of Wilson fermions on mesonic correlators in the epsilon-regime using Wilson chiral perturbation theory (WChPT). We generalize the epsilon-expansion of continuum ChPT to nonzero…
A quantitative understanding of isospin violation is an increasingly important ingredient for the extraction of the nucleon's strange vector form factors from experimental data. We calculate the isospin violating electric and magnetic form…
We present a status report on our study of long-distance contributions to the decay amplitudes A(K^0 --> pi pi, I) in the framework of the 1/N expansion. We argue that a modified prescription for the identification of meson momenta in the…
Isospin-breaking effects, in particular those associated with electroweak-penguin contributions and pi0-eta,eta' mixing, have long been known to affect the Standard Model prediction of Re(epsilon'/epsilon) in a significant manner. We have…
Isospin is an almost exact symmetry of strong interactions and the corrections to the isosymmetric limit are, in general, at the percent level. For several hadronic quantities, such as pseudoscalar meson masses or the kaon leptonic and…
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…
We consider chiral loop corrections to the effective couplings which describe the strong interactions of two heavy mesons of even or odd parities and a light pseudoscalar meson, within a framework which combines heavy quark effective theory…
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…