Baryonia and near-threshold enhancements

TL;DR

This paper investigates baryon-antibaryon spectra with strange, charm, and bottom quarks using a color flux-tube model, predicting stable low-spin hexaquark states that could explain certain observed near-threshold enhancements.

Contribution

It introduces a multi-body confinement interaction in the flux-tube model to predict stable baryon-antibaryon bound states, offering a new interpretation of several exotic states.

Findings

Many low-spin baryon-antibaryon states can form stable hexaquarks.

Multi-body confinement is crucial for binding these states.

Some observed states may be interpreted as baryon-antibaryon molecules.

Abstract

The baryon-antibaryon spectrum consisting of strange, charm and bottom quarks is studied in the color flux-tube model with a multi-body confinement interaction. Numerical results indicate that many low-spin baryon-antibaryon states can form compact hexaquark states and are stable against the decay into a baryon and an antibaryon. The multi-body confinement interaction as a binding mechanism plays an important role in the formation of the states. They can be searched in the $e^+e^-$ annihilation and charmonium or bottomonium decay if they really exist. The newly reported states, X(1835), X(2370), Y(2175), Y(4360) and Y_b(10890), may be interpreted as $N\bar{N}$, $\Delta\bar{\Delta}$, $\Lambda\bar{\Lambda}$, $\Lambda_c\bar{\Lambda}_c$ and $\Lambda_b\bar{\Lambda}_b$ states, respectively.