Strange partner of $T_{cc}^+$ from lattice QCD in $D^{(*)}D_s^{(*)}$ scattering

TL;DR

This lattice QCD study investigates possible $ccar{u}ar{s}$ tetraquarks near threshold by analyzing coupled $DD_s^* - D^*D_s$ and elastic $DD_s$ scattering, finding no evidence of bound states.

Contribution

First lattice QCD analysis of coupled $D D_s^* - D^* D_s$ scattering in the $J^P=1^+$ channel near threshold, exploring tetraquark existence.

Findings

Weak meson interactions observed with small spectral shifts.

No pole structures near threshold in $S$-wave amplitudes.

Results suggest no bound tetraquark states in studied channels.

Abstract

We report on our lattice QCD study of coupled $DD_s^* - D^*D_s$ scattering in the $J^P=1^+$ channel and elastic $DD_s$ scattering in the $J^P=0^+$ channel, aimed at investigating the possible existence of $cc\bar{u}\bar{s}$ tetraquarks near threshold. The calculation uses CLS ensembles with $m_\pi \approx 280$ MeV, lattice spacing $a \approx 0.09$ fm, and spatial extents $L/a=24, 32$. Finite-volume spectra are obtained from a variational analysis of two-point correlation matrices constructed from two-meson operator bases using distillation. The $l=0$ partial-wave scattering amplitudes are determined from the lattice spectra in multiple moving frames using L\"uscher's formalism as well as a finite-volume implementation of the Lippmann-Schwinger equation. In both channels we observe small but nonzero shifts relative to the noninteracting spectrum, indicating weak meson interactions. The extracted physically plausible $S$-wave amplitudes show no pole structures near threshold.