Imaging Dynamical Chiral-Symmetry Breaking: Pion Wave Function on the Light Front

Lei Chang, I. C. Cloët, J. J. Cobos-Martinez, C. D. Roberts, S. M. Schmidt, and P. C. Tandy

Phys. Rev. Lett. 110, 132001 – Published 28 March 2013

Abstract

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, $φ_{π}^{asy} (x) = 6 x (1 - x)$ ; e.g., the integral of $φ_{π} (x) / φ_{π}^{asy} (x)$ is 1.8 using the simplest kernel and 1.5 with the more sophisticated kernel. Independent of the kernels, the emergent phenomenon of dynamical chiral-symmetry breaking is responsible for hardening the amplitude.

Received 2 January 2013

DOI:https://doi.org/10.1103/PhysRevLett.110.132001

Authors & Affiliations

Lei Chang¹, I. C. Cloët^2,3, J. J. Cobos-Martinez^4,5, C. D. Roberts^3,6, S. M. Schmidt⁷, and P. C. Tandy⁴

¹Institut für Kernphysik, Forschungszentrum Jülich, D-52425 Jülich, Germany
²CSSM and CoEPP, School of Chemistry and Physics University of Adelaide, Adelaide, South Australia 5005, Australia
³Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
⁴Department of Physics, Center for Nuclear Research, Kent State University, Kent Ohio 44242, USA
⁵Departamento de Física, Universidad de Sonora, Boulevard Luis Encinas J. y Rosales, Colonia Centro, Hermosillo, Sonora 83000, Mexico
⁶Department of Physics, Illinois Institute of Technology, Chicago, Illinois 60616-3793, USA
⁷Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, D-52425 Jülich, Germany