Bottom Tetraquark Production at RHIC?

TL;DR

This paper investigates the production of bottom tetraquarks and double $A8$ states at RHIC, finding that the observed resonance's mass is inconsistent with predictions from a specific Fock state model.

Contribution

It introduces a model based on a $|uud b\overline b b\overline b\rangle$ Fock state to calculate $A8$ pair and tetraquark production, comparing results with experimental data.

Findings

Double $A8$ production peaks in the detector's rapidity range.

Calculated masses are higher than the observed resonance mass.

Results are incompatible with the experimental resonance but align with previous tetraquark predictions.

Abstract

Background: A resonance has been observed by the ANDY Collaboration at the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory in Cu+Au collisions at center-of-mass energy $\sqrt{s} = 200$ GeV and at forward rapidity with an average mass of 18.15 GeV. The Collaboration suggests that it is a $b \overline b b \overline b$ tetraquark state decaying to two $\Upsilon$(1S) states, each measured through the $\Upsilon \rightarrow ggg$ channel. Purpose: Their suggestion is investigated assuming that the two $\Upsilon$ states are produced through the materialization of a $|uud b\overline b b \overline b \rangle$ Fock state in the projectile. Methods: The $\Upsilon$ pair mass and rapidity distributions arising from such a state are calculated. The production of an $X_b(b \overline b b \overline b)$ tetraquark state from the same Fock configuration is also investigated. The dependence on bottom quark mass and their transverse momentum range is also studied. Results: It is found that double $\Upsilon$ production from these $|uud b \overline b b \overline b \rangle$ states peak in the rapidity range of the ANDY detector. The $\Upsilon$ pair and $X_b$ masses are, however, higher than the mass reported by the ANDY Collaboration. Conclusions: The results obtained from these calculations are incompatible with the ANDY result. They are, however, compatible with previous predictions of $b \overline b b \overline b$ tetraquark masses.