Possible Deuteron-like Molecular States Composed of Heavy Baryons

TL;DR

This study investigates the potential existence of loosely bound heavy baryon pairs, similar to deuterons, using a comprehensive one boson exchange model including various meson exchanges and spin effects.

Contribution

It provides the first systematic analysis of heavy baryon pairs considering multiple meson exchanges and spin mixing effects, predicting possible bound states.

Findings

No bound state for $ ext{Lambda}_c ext{Lambda}_c$.

Possible loosely bound states for $ ext{Xi}_c ext{Xi}_c$ and $ ext{Xi}_c^ ext{'} ext{Xi}_c^ ext{'}$.

Large RMS radii indicating weak binding.

Abstract

We perform a systematic study of the possible loosely bound states composed of two charmed baryons or a charmed baryon and an anti-charmed baryon within the framework of the one boson exchange (OBE) model. We consider not only the $\pi$ exchange but also the $\eta$, $\rho$, $\omega$, $\phi$ and $\sigma$ exchanges. The $S-D$ mixing effects for the spin-triplets are also taken into account. With the derived effective potentials, we calculate the binding energies and root-mean-square (RMS) radii for the systems $\Lambda_c\Lambda_c(\bar{\Lambda}_c)$, $\Xi_c\Xi_c(\bar{\Xi}_c)$, $\Sigma_c\Sigma_c(\bar{\Sigma}_c)$, $\Xi_c^\prime\Xi_c^\prime(\bar{\Xi}_c^\prime)$ and $\Omega_c\Omega_c(\bar{\Omega}_c)$. Our numerical results indicate that: (1) the H-dibaryon-like state $\Lambda_c\Lambda_c$ does not exist; (2) there may exist four loosely bound deuteron-like states $\Xi_c\Xi_c$ and $\Xi_c^\prime\Xi_c^\prime$ with small binding energies and large RMS radii.