Comparing meson-meson and diquark-antidiquark creation operators for a $\bar b \bar b u d$ tetraquark

TL;DR

This study compares meson-meson and diquark-antidiquark structures in a $ar b ar b u d$ tetraquark, revealing dominance of diquark-antidiquark at short distances and meson pairs at larger separations.

Contribution

It provides a detailed analysis of the internal structure of a $ar b ar b u d$ tetraquark using creation operators, highlighting the dominance of diquark-antidiquark configurations at short ranges.

Findings

Diquark-antidiquark dominance for $r < 0.2$ fm.

System resembles two $B$ mesons for $r > 0.5$ fm.

Approximate 58 ext{ extbackslash}%/42 ext{ extbackslash}%} ratio between meson-meson and diquark-antidiquark configurations.

Abstract

We compare two frequently discussed competing structures for a stable $\bar b \bar b u d$ tetraquark with quantum numbers $I(J^P) = 0(1^+)$ by considering a meson-meson as well as a diquark-antidiquark creation operator. We treat the heavy antiquarks as static with fixed positions and find diquark-antidiquark dominance for $\bar b \bar b$ separations $r < 0.2 \, \text{fm}$, while for $r > 0.5 \, \text{fm}$ the system essentially corresponds to a pair of $B$ mesons. For the meson-meson to diquark-antidiquark ratio of the tetraquark we obtain around $58\%/42\%$.