Chiral Unitary Dynamics of Hadrons and Hadrons in a Nuclear Medium

TL;DR

This paper reviews recent advances in chiral unitary models describing hadron resonances, highlighting dynamically generated states across various meson and baryon systems, supported by experimental findings.

Contribution

It provides a comprehensive overview of how chiral unitary dynamics can generate and explain various hadron resonances, including new states supported by recent experiments.

Findings

Axial vector mesons are dynamically generated from pseudoscalar and vector meson interactions.

Recent experiments support the existence of a new hidden charm scalar state.

Certain baryon resonances can be described as meson-baryon bound states or resonances.

Abstract

In this talk I summarize recent findings around the description of axial vector mesons as dynamically generated states from the interaction of pseudoscalar mesons and vector mesons, dedicating some attention to the two $K_1(1270)$ states. Then I review the generation of open and hidden charm scalar and axial states, and how some recent experiment supports the existence of the new hidden charm scalar state predicted. I present recent results showing that the low lying $1/2^+$ baryon resonances for S=-1 can be obtained as bound states or resonances of two mesons and one baryon in coupled channels. Then show the differences with the S=0 case, where the $N^*(1710)$ appears also dynamically generated from the two pion one nucleon system, but the $N^*(1440)$ does not appear, indicating a more complex structure of the Roper resonance. Finally I shall show how the state X(2175), recently discovered at BABAR and BES, appears naturally as a resonance of the $\phi K \bar{K}$ system.