Study of some (non-)conventional mesons in the framework of effective models

Abstract

The main aim of our study is to understand the nature of some conventional and non-conventional mesonic states by applying effective QFT models. We start from the relativistic Lagrangians containing a unique $q\bar{q}$ seed state which is strongly coupled to the low-masses decay products of the original state. We find out that some states may appear as a dynamically generated companion poles of the heavier $q\bar{q}$ mesons. In particular we show that $K_0^{\ast }(700)$ is a companion pole of the well-known $K_0^{\ast }(1430)$ resonance, $X(3872)$ emerges as a (virtual) companion pole of ${\chi }_{c1}(2P)$, and the puzzling $Y(4008)$ is not a real state, but a spurious enhancement which appears when studying the state $\psi (4040)$.

Comments: 6 pages, 1 figure, Prepared for the proceedings of eQCD2020, Excited QCD 2020, Krynica-Zdrój, Poland, 2-8 February 2020