The Z(4430) and a New Paradigm for Spin Interactions in Tetraquarks

TL;DR

This paper introduces a new diquark-antidiquark model for tetraquarks that effectively explains recent experimental observations of charged tetraquarks and Y resonances, offering a fresh perspective on spin interactions.

Contribution

The paper proposes a 'type-II' diquark-antidiquark model that simplifies and unifies the understanding of tetraquark states with specific quantum numbers, advancing theoretical descriptions.

Findings

Successfully models the J^{PG}=1^{++} and 1^{--} tetraquark sectors

Provides a comprehensive picture of charged tetraquarks and Y resonances

Highlights unresolved issues with isospin multiplet completeness

Abstract

Following the recent confirmation of the Z+(4430) resonance with J^{PG}=1^{++}, we have re-examined the model of S- and P-wave tetraquarks. We propose a `type-II' diquark-antidiquark model which shows to be very effective at producing a simple and comprehensive picture of the J^{PG}=1^{++} and 1^{--} sectors of the recently discovered charged tetraquarks and of the observed Y resonances. The model is still faced with the unresolved difficulty of explaining why some states seem to have incomplete isospin multiplets.