The non-perturbative unquenched quark model

P.G Ortega,F Fernández,D.R Entern

doi:10.1051/epjconf/201713706008

P.G Ortega, F Fernández + Show 1 more

Open Access

https://doi.org/10.1051/epjconf/201713706008

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Abstract

In recent years states in the quarkonium spectrum not expected in the naive quark model have appeared and created a lot of interest. In the theoretical side the study of the effect of meson-meson thresholds in the spectrum have been performed in different approximations. In a quark model framework, and in the spirit of the Cornell model, when a meson-meson threshold is included, the coupling to all the quark-antiquark states have to be considered. In practice only the closest states are included perturbatively. In this contribution we will present a framework in which we couple quark-antiquark states with meson-meson states non-perturbatively, taking into account effectively the coupling to all quark-antiquark states. The method will be applied to the study of the X (3872) and a comparison with the perturbative calculation will be performed.

Highlights

Since the discovery of the X(3872) in 2003 [1] it became evident that the naive quark model would not be enough to describe all the hadron spectrum
Our point of view was slightly different, since we studied the effects of the bare quark-antiquark states in the dynamics of the twomeson states, which was solved using a Schrödinger like equation
We present the results of the new framework applied to the 1++ sector of the charmonium spectrum

Summary

Introduction

Since the discovery of the X(3872) in 2003 [1] it became evident that the naive quark model would not be enough to describe all the hadron spectrum. Our point of view was slightly different, since we studied the effects of the bare quark-antiquark states in the dynamics of the twomeson states, which was solved using a Schrödinger like equation This allowed us to find new states not present in the naive quark model. The main idea is not to expand the quark-antiquark wave function in a linear combination of bare quark-antiquark states, but leave the radial wave function as an unknown of the problem solving for it In this contribution we will describe this framework an apply it to the study of the charmonium spectrum in the 1++ channel and in particular to the X(3872). We will show that when the 3P0 coupling is small the results are the same as the perturbative calculation

The Chiral Quark Model

Framework

Results

Summary