We project onto the light front the pion's Poincaré-covariant Bethe-Salpeter wave function obtained using two different approximations to the kernels of quantum chromodynamics' Dyson-Schwinger equations. At an hadronic scale, both computed results are concave and significantly broader than the asymptotic distribution amplitude, φ(π)(asy)(x)=6x(1-x); e.g., the integral of φ(π)(x)/φ(π)(asy)(x) is...

the primary immunodeficiency (pi) disorders are abnormalities in development and maturation of the immune system. individuals with pi disease may experience frequent infections, which limit their abilities to exhibit physical and psychological well-being secondary to their illness. in this survey we compared health-related quality of life of primary immune deficient patients with healthy childr...

We consider Compton scattering by a pion in the framework of chiral perturbation theory. We investigate off–shell effects in the s– and u–channel pole diagrams. For that purpose we perform a field transformation which, in comparison with the standard Gasser and Leutwyler Lagrangian, generates additional terms at order p4 proportional to the lowest–order equation of motion. As a result of the eq...