Institute of Physics, Jan Kochanowski University,
2 Institute of Nuclear Physics PAN, 31-342 Cracow, Poland
3 Departamento de Física Atómica, Molecular y Nuclear and Instituto Carlos I de Física Teórica y Computacional, Universidad de Granada, 18071 Granada, Spain
Accepted: 27 October 2020
Published online: 21 December 2020
We present a brief review of results of chiral quark models for soft matrix elements in the pion state, appearing in high-energy processes as well as accessible in present and future lattice studies. A particular attention is paid to the recently explored double parton distribution functions of the pion.
Dedicated to David Blaschke on the occasion of his 60th birthday. Presented by WB at The 40th Max Born Symposium Three Days on Strong Correlations in Dense Matter, 9-12 October 2019, Wrocław, Poland.
© The Author(s) 2020
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.