Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

New molecular bonds existing in the strong interaction

Hua-Xing Chen

Abstract

Similar to the covalent bond in chemical molecules induced by shared electrons, we proposed in [Commun. Theor. Phys. 74 (2022) 125201] the hadronic covalent bond induced by shared light quarks to explain the $T_{cc}(3875)$ and the deuteron. In this paper we improve and extend this mechanism to explain the $Z_c(3900)$, which is bound by the shared light quark-antiquark pair along with sea quark-antiquark pairs from the vacuum. Our analysis is based on the following forward and backward reasoning: a hadronic molecule exists, iff the attraction between its components is strong enough, iff the wave functions of its components significantly overlap with each other, iff the Pauli principle is well satisfied among all the shared quarks and antiquarks. Additionally, the $X(3872)$ is so unique that we need to further consider the annihilation of the shared light quark-antiquark pair, just in line with the reasoning that the creation and annihilation of sea quark-antiquark pairs should be given equal consideration. Both the creation and annihilation molecular bonds exist only in the strong interaction, not in the electromagnetic interaction, and they provide a quasi-static low-energy platform for studying the QCD confinement.

New molecular bonds existing in the strong interaction

Abstract

Similar to the covalent bond in chemical molecules induced by shared electrons, we proposed in [Commun. Theor. Phys. 74 (2022) 125201] the hadronic covalent bond induced by shared light quarks to explain the and the deuteron. In this paper we improve and extend this mechanism to explain the , which is bound by the shared light quark-antiquark pair along with sea quark-antiquark pairs from the vacuum. Our analysis is based on the following forward and backward reasoning: a hadronic molecule exists, iff the attraction between its components is strong enough, iff the wave functions of its components significantly overlap with each other, iff the Pauli principle is well satisfied among all the shared quarks and antiquarks. Additionally, the is so unique that we need to further consider the annihilation of the shared light quark-antiquark pair, just in line with the reasoning that the creation and annihilation of sea quark-antiquark pairs should be given equal consideration. Both the creation and annihilation molecular bonds exist only in the strong interaction, not in the electromagnetic interaction, and they provide a quasi-static low-energy platform for studying the QCD confinement.

Paper Structure

This paper contains 9 sections, 10 equations, 2 figures, 1 table.

Table of Contents

  1. Introduction
  2. Covalent bond
  3. $T_{cc}(3875)$
  4. Deuteron
  5. A toy model
  6. Creation bond
  7. Summary and Discussions
  8. Other configurations for the creation bond
  9. A brief investigation into the hidden-charm baryonium state

Figures (2)

  • Figure 1: Possible binding mechanisms induced by: (a) shared light quarks, (b) the shared light quark-antiquark pair along with sea quark-antiquark pairs from the vacuum, and (c) the annihilation of the shared light quark-antiquark pair.
  • Figure 2: Possible binding mechanism for the $T_{cc}(3875)$ as the $\bar{D} \bar{D}^*$ hadronic molecule with $(I)J^P = (0)1^+$, due to the hadronic covalent bond induced by shared light quarks.