Investigation of deuteron-like singly bottomed dibaryon resonances

TL;DR

The paper investigates deuteron-like singly bottomed dibaryons with strangeness $S=-1,-3,-5$ within a chiral quark framework, employing resonating group methods and multi-channel scattering to identify bound and resonance states for $J=1$, $I=0$. It finds no bound or resonant states for $S=-3$ and $S=-5$, while in $S=-1$ four channels exhibit strong attraction that yields two resonances after open-closed channel coupling: a compact SigmaSigma_b around 6975 MeV and a deuteron-like SigmaSigma_b^* near 7000 MeV. Phase-shift analyses and RMS-radius calculations reveal that channel coupling is essential in distinguishing bound versus resonant or molecular configurations. The results provide concrete predictions for new bottomed dibaryons and emphasize that scattering processes and channel coupling are effective tools for uncovering genuine multiquark states.

Abstract

We perform a systematical investigation of the existence of the deuteron-like singly bottomed dibaryon resonance states with strangeness $S=-1,~-3,~-5$ in the chiral quark model. Two resonance states with strangeness $S=-1$ are obtained in the baryon-baryon scattering process. The first candidate is $ΣΣ_b$ in the $ΛΛ_b$ and $NΞ_b^*$ scattering process, with the resonance energy 6974.22 MeV - 6975.37 MeV and the decay width 14.450 MeV, respectively; the other one is $ΣΣ_b^*$ in the $NΞ_b$ and $NΞ'_b$ scattering process, with the resonance energy 6990.69 MeV - 7008.37 MeV and the decay width 43.790 MeV, respectively. The Root Mean Square (RMS) radius calculation shows that the former tends to be in a compact structure, while the latter tends to be in a molecular structure. Both of these resonance states are worthy of experimental exploration. Furthermore, it should be emphasized that the effect of channel-coupling is of great importance in exploring exotic hadron states, and investigating the scattering process may serve as an effective approach to identifying genuine resonances.

Figures (9)

• Figure 1: The effective potentials of different channels for singly bottomed dibaryons with $S=-1$.
• Figure 2: The effective potentials of different channels for singly bottomed dibaryons with $S=-3$.
• Figure 3: The effective potentials of different channels for singly bottomed dibaryons with $S=-5$.
• Figure 4: The $\Lambda \Lambda_b$ phase shifts with two-channel coupling.
• Figure 5: The $N\Xi_b$ phase shifts with two-channel coupling.