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arXiv · 2608.07670

Quest for an Understanding of Pion and Kaon Structure

Zhen-Ni Xu·Daniele Binosi·Craig D. Roberts·José Rodríguez-Quintero
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Abstract

The emergence of massless (Nambu-Goldstone) bosons in association with a dynamically global broken symmetry is a long known and widespread phenomenon in physics. However, practically nothing is known about the expressions of Nambu--Goldstone boson character on the internal structure of these bound states. Indeed, their structure is often ignored. In strong interactions, pions and kaons are the (would-be) Nambu-Goldstone bosons and experiments underway or planned at existing or anticipated high-energy, high-luminosity facilities will gather data that it is hoped will enable maps to be drawn of their internal structure. Meanwhile, theory and phenomenology find themselves in something of a quagmire. Herein, we provide a snapshot of the current status, highlighting issues under debate and identifying areas that deserve greater attention so that best use can be made of what is likely to be a huge volume of data delivered in the next decade or so.

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Zhen-Ni Xu, Daniele Binosi, Craig D. Roberts, José Rodríguez-Quintero. 2026-08-07. Quest for an Understanding of Pion and Kaon Structure. https://arxiv.org/abs/2608.07670

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