Regarding the distribution of glue in the pion

Abstract

Understanding why the scale of emergent hadron mass is obvious in the proton but hidden in the pion may rest on mapping the distribution functions (DFs) of all partons within the pion and comparing them with those in the proton; and since glue provides binding in quantum chromodynamics, the glue DF could play a special role. Producing reliable predictions for the proton's DFs is difficult because the proton is a three valence-body bound-state problem. As sketched herein, the situation for the pion, a two valence-body problem, is much better, with continuum and lattice predictions for the valence-quark and glue DFs in agreement. This beginning of theory alignment is timely because experimental facilities now either in operation or planning promise to realise the longstanding goal of providing pion targets, thereby enabling precision experimental tests of rigorous theory predictions concerning Nature's most fundamental Nambu-Goldstone bosons.

7 pages, 5 figures. Accepted for publication in Chinese Physics Letters

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Cited by in corpus (9)

• Gauge Sector Dynamics in QCD
• Valence quark ratio in the proton
• Pion charge radius from pion+electron elastic scattering data
• Hadron and light nucleus radii from electron scattering
• Gluon and valence quark distributions for the pion and kaon in nuclear matter
• Fixed-target charmonium production and pion parton distributions
• Revealing pion and kaon structure via generalised parton distributions
• Global QCD Analysis of Pion Parton Distributions with Threshold Resummation
• Searching for $a_0(980)$-meson parton distribution function