The dynamical diquark model: fine structure and isospin

Jesse F. Giron; Richard F. Lebed; Curtis T. Peterson

doi:10.1007/JHEP01(2020)124

The dynamical diquark model: fine structure and isospin

Jesse F. Giron, Richard F. Lebed, Curtis T. Peterson

Physics

Research output: Contribution to journal › Article › peer-review

14 Scopus citations

Abstract

We incorporate fine-structure corrections into the dynamical diquark model of multiquark exotic hadrons. These improvements include effects due to finite diquark size, spin-spin couplings within the diquarks, and most significantly, isospin-dependent couplings in the form of pionlike exchanges assumed to occur between the light quarks within the diquarks. Using a simplified two-parameter interaction Hamiltonian, we obtain fits in which the isoscalar J^PC = 1⁺⁺ state — identified as the X (3872) — appears naturally as the lightest exotic (including all states that are predicted by the model but have not yet been observed), while the closed-charm decays of Z_c(3900) and Z_c(4020) prefer J/𝜓 and h_c modes, respectively, in accord with experiment. We explore implications of this model for the excited tetraquark multiplets and the pentaquarks.

Original language	English (US)
Article number	124
Journal	Journal of High Energy Physics
Volume	2020
Issue number	1
DOIs	https://doi.org/10.1007/JHEP01(2020)124
State	Published - Jan 1 2020

Keywords

Phenomenological Models
QCD Phenomenology

ASJC Scopus subject areas

Nuclear and High Energy Physics

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10.1007/JHEP01(2020)124

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title = "The dynamical diquark model: fine structure and isospin",

abstract = "We incorporate fine-structure corrections into the dynamical diquark model of multiquark exotic hadrons. These improvements include effects due to finite diquark size, spin-spin couplings within the diquarks, and most significantly, isospin-dependent couplings in the form of pionlike exchanges assumed to occur between the light quarks within the diquarks. Using a simplified two-parameter interaction Hamiltonian, we obtain fits in which the isoscalar JPC = 1++ state — identified as the X (3872) — appears naturally as the lightest exotic (including all states that are predicted by the model but have not yet been observed), while the closed-charm decays of Zc(3900) and Zc(4020) prefer J/휓 and hc modes, respectively, in accord with experiment. We explore implications of this model for the excited tetraquark multiplets and the pentaquarks.",

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AU - Lebed, Richard F.

AU - Peterson, Curtis T.

N1 - Funding Information: This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited Publisher Copyright: © 2020, The Author(s).

PY - 2020/1/1

Y1 - 2020/1/1

N2 - We incorporate fine-structure corrections into the dynamical diquark model of multiquark exotic hadrons. These improvements include effects due to finite diquark size, spin-spin couplings within the diquarks, and most significantly, isospin-dependent couplings in the form of pionlike exchanges assumed to occur between the light quarks within the diquarks. Using a simplified two-parameter interaction Hamiltonian, we obtain fits in which the isoscalar JPC = 1++ state — identified as the X (3872) — appears naturally as the lightest exotic (including all states that are predicted by the model but have not yet been observed), while the closed-charm decays of Zc(3900) and Zc(4020) prefer J/휓 and hc modes, respectively, in accord with experiment. We explore implications of this model for the excited tetraquark multiplets and the pentaquarks.

AB - We incorporate fine-structure corrections into the dynamical diquark model of multiquark exotic hadrons. These improvements include effects due to finite diquark size, spin-spin couplings within the diquarks, and most significantly, isospin-dependent couplings in the form of pionlike exchanges assumed to occur between the light quarks within the diquarks. Using a simplified two-parameter interaction Hamiltonian, we obtain fits in which the isoscalar JPC = 1++ state — identified as the X (3872) — appears naturally as the lightest exotic (including all states that are predicted by the model but have not yet been observed), while the closed-charm decays of Zc(3900) and Zc(4020) prefer J/휓 and hc modes, respectively, in accord with experiment. We explore implications of this model for the excited tetraquark multiplets and the pentaquarks.

KW - Phenomenological Models

KW - QCD Phenomenology

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JO - Journal of High Energy Physics

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ER -

The dynamical diquark model: fine structure and isospin

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Keywords

ASJC Scopus subject areas

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