Exotic $T_{c\bar s0}^a(2900)^0$ and $T_{c\bar s0}^a(2900)^{++}$ states in Born-Oppenheimer approximation

TL;DR

This paper uses the Born-Oppenheimer approximation within a dynamical diquark model to analyze the mass spectrum and structure of the exotic $T_{car s0}^a(2900)$ states, suggesting they are compact tetraquarks.

Contribution

It applies the Born-Oppenheimer approximation to exotic tetraquark states, providing new insights into their structure and confirming their compactness as diquark-antidiquark systems.

Findings

States are best described as axial-vector diquark pairs.

Calculated radii indicate these are compact tetraquarks.

Results support a diquark-antidiquark configuration.

Abstract

We employ Born-Oppenheimer approximation to the $T_{c\bar s0}^a(2900)^0$ and $T_{c\bar s0}^a(2900)^{++}$ states observed by the LHCb Collaboration and study mass spectrum and root-mean-square radius values. For this purpose, we use dynamical diquark model. We assume that strange quark is a heavy for the usage of Born-Oppenheimer approximation. Our results strongly indicate that the $T_{c\overline{s}0}^{a}(2900)$ states are best described as composed of axial-vector (spin-1) diquark pairs. Furthermore, the calculated root-mean-square radius, $\langle r^{2}\rangle^{1/2} \approx 0.70-0.80$ fm, which is significantly less than 1 fm, provides compelling evidence that these are compact tetraquarks rather than loosely bound hadronic molecules.