The Inevitable Quark Three-Body Force and its Implications for Exotic States

TL;DR

This paper derives the form of quark three-body forces from nuclear physics principles and explores their impact on exotic states, indicating these states are likely molecular rather than compact due to additional repulsion.

Contribution

It introduces a form of quark three-body interactions and demonstrates their importance in extending the quark model to include exotic states with implications for their structure.

Findings

Quark three-body interactions add about 10 MeV repulsion to exotic states.

These interactions suggest tetraquark states are more likely molecular than compact.

The model successfully fits meson spectra with the same parameters, including baryons.

Abstract

Three-body nuclear forces are essential for explaining the properties of light nuclei with a nucleon number greater than three. Building on insights from nuclear physics, we extract the form of quark three-body interactions and demonstrate that these terms are crucial for extending the quark model fit of the meson spectrum to include baryons using the same parameter set. We then discuss the implications of our findings for exotic configurations involving more than three quarks, such as the $T_{cc}$ and $\chi_{c1}(3872)$. We find that the quark three-body interactions provide additional repulsion on the order of 10 MeV for the compact configurations of both the $T_{cc}$ and $\chi_{c1}(3872)$. This result, combined with previous calculations, strongly suggests that these tetraquark states are molecular rather than compact states.