What is the mechanism of the $T_{4c}(6900)$ tetraquark production?

TL;DR

This paper investigates the production mechanisms of the recently observed fully charm tetraquark at 6.9 GeV, analyzing both single and double parton scattering processes using the $k_t$-factorization approach.

Contribution

It provides the first detailed calculation of the $T_{4c}(6900)$ production via SPS and DPS mechanisms, including invariant mass and transverse momentum distributions.

Findings

SPS and DPS mechanisms contribute to tetraquark production.

Calculated distributions match experimental observations.

Different spin scenarios affect production rates.

Abstract

We discuss the production mechanism of fully charm tetraquark, observed recently by the LHCb at M = 6.9 GeV in the $J/\psi J/\psi$ channel. Both single parton scattering (SPS) and double parton scattering (DPS) mechanisms are considered. We calculate the distribution in the invariant mass of the four-quark system $M_{4c}$ for SPS and DPS production of $c c \bar c \bar c$ in the $k_t$-factorization approach. We present transverse momentum distribution in $p_{t,4c}$ for $c \bar c c \bar c$ system in a mass window around tetraquark mass. The calculation of the SPS $g^* g^* \to T_{4c}(6900)$ fusion mechanism is performed in the $k_T$-factorization approach assuming different spin scenarios ($0^+$ and $0^-$).