Speaker
Description
We present a leading-order NRQCD factorization analysis of the exclusive two-photon production of spin-0 and spin-2 fully-charmed tetraquarks, $\gamma\gamma\to T_{4c}\left(0^{++}, 2^{++}\right)$. The respective short-distance coefficients are collected, enabling predictions for the two-photon decay widths $\Gamma\left( T_{4c}\to \gamma \gamma \right)$ in terms of non-relativistic long-distance matrix elements. Using these results, we provide estimates for the production cross sections of $T_{4c}$ states via photon–photon fusion in ultra-peripheral collisions at the LHC. Our work provides crucial theoretical input for ongoing experimental searches and establishes a quantitative framework to discriminate between different structural configurations of the of the $X\left(6900\right)$.
