Tetraquark Cusp Effects from Diquark Pair Production

TL;DR

This paper investigates how diquark-antidiquark pair production causes cusp effects that influence the movement of resonant poles, with implications for understanding exotic hadron states.

Contribution

It introduces the first analysis of diquark cusp effects on resonant poles and compares their impact to meson cusp effects across different energy scales.

Findings

Diquark cusps are more effective at charm and higher energy scales.

Meson cusps are more influential at lower energies like the $Kar{K}$ threshold.

The cusp profile is derived from constituent counting rules.

Abstract

We present the first study of the cusp effect (the movement of resonant poles due to the proximity of multiparticle thresholds) caused by the creation of diquark-antidiquark pairs. The cusp profile for such states is obtained from constituent counting rules. We compare the effectiveness of diquark cusps in moving resonant poles with that from a phenomenological form commonly used for meson-pair creation, and find that mesons tend to be more effective at lower energies $({\it e.g.}$, the $K\overline{K}$ threshold), while diquarks tend to be more effective at the charm [$X(3872)$] scales and above.