Revealing pion and kaon structure via generalised parton distributions

Supported by National Natural Science Foundation of China (12135007, 11805097); Jiangsu Provincial Natural Science Foundation of China (BK20180323); Spanish Ministry of Science and Innovation (MICINN) (PID2019-107844GB-C22); Junta de Andalucia (P18-FR-5057, UHU-1264517); and University of Huelva (EPIT-2019)Clear windows onto emergent hadron mass (EHM) and modulations thereof by Higgs boson interactions are provided by observable measures of pion and kaon structure, many of which are accessible via generalised parton distributions (GPDs). Beginning with algebraic GPD Ansatze, constrained entirely by hadron-scale pi and K valence-parton distribution functions (DFs), in whose forms both EHM and Higgs boson influences are manifest, numerous illustrations are provided. They include the properties of electromagnetic form factors, impact parameter space GPDs, gravitational form factors and associated pressure profiles, and the character and consequences of all-orders evolution. The analyses predict that mass-squared gravitational form factors are stiffer than electromagnetic form factors; reveal that K pressure profiles are tighter than pi profiles, with both mesons sustaining near-core pressures at magnitudes similar to that expected at the core of neutron stars; deliver parameter-free predictions for pi and K valence, glue, and sea GPDs at the resolving scale zeta = 2 GeV; and predict that at this scale the fraction of meson mass-squared carried by glue and sea combined matches that lodged with the valence degrees-of-freedom, with a similar statement holding for mass-squared radii.National Natural Science Foundation of China (NSFC) 12135007 11805097Natural Science Foundation of Jiangsu Province BK20180323Spanish GovernmentEuropean Commission PID2019-107844GB-C22Junta de Andalucia P18-FR-5057UHU-1264517 University of Huelva EPIT-201