We review the structure of Roy–Steiner equations for pion–nucleon scattering, the solution
for the partial waves of the t-channel process π π→ N ̄ N, as well as the high-accuracy …

We highlight the progress, current status, and open challenges of QCD-driven physics, in
theory and in experiment. We discuss how the strong interaction is intimately connected to a …

The theoretical predictions for the subtraction constants lead to a very accurate dispersive
representation of the ππ scattering amplitude below 0.8 GeV. The extension of this …

The dispersive analysis of the decay η → 3 π η→ 3 π is reviewed and thoroughly updated
with the aim of determining the quark mass ratio Q^ 2=(m_s^ 2-m_ ud^ 2)/(m_d^ 2-m_u^ 2) …

Recent results and future prospects of particle physics experiments with neutral and charged
K-meson (kaon) decays are reviewed. Topics include CP violation, rare decays, leptons in …

The results of a search for hydrogen-like atoms consisting of π∓ K±mesons are presented.
Evidence for πK atom production by 24 GeV/c protons from CERN PS interacting with a …

After having announced the statistically significant observation (5.6 σ) of the new exotic π K
atom, the DIRAC experiment at the CERN proton synchrotron presents the measurement of …

In this article, we analyze the role of an external electric field, in the weak field
approximation, on π-π scattering lengths. The discussion is presented in the frame of the …

The observation of hydrogenlike π K atoms, consisting of π-K+ or π+ K-mesons, is
presented. The atoms are produced by 24 GeV/c protons from the CERN PS accelerator …

$\newcommand {\qbar}{\bar {q}}\newcommand {\ubar}{\bar {u}}\newcommand {\dbar}{\bar
{d}}\newcommand {\sbar}{\bar {s}}\newcommand {\lvac}{\langle 0|\,}\newcommand {\rvac} …