Speaker
Description
The $\bar D N$ system is one of the simplest hadronic systems containing an open-charmed meson and a nucleon, yet its low-energy interaction remains to be fully understood. Existing phenomenological models predict interactions ranging from sufficiently strong attraction to form a pentaquark state to weak attraction or repulsion. On the experimental side, higher-statistics LHC Run 3 data are expected to provide improved constraints, making first-principles lattice QCD calculations increasingly relevant for comparison with forthcoming experimental measurements and phenomenological models.
In this talk, we present updated results for the $\bar D N$ potential and its $s$-wave scattering parameters obtained using the HAL QCD method. (2+1)-flavor lattice QCD simulations were performed at the physical point with gauge configurations generated by the HAL QCD Collaboration (“HAL-conf-2023”) on a $96^3 \times 96$ lattice with pion mass $m_\pi \simeq 137$ MeV and lattice spacing $a \simeq 0.0844$ fm. The present work includes additional studies of systematic uncertainties together with a comparison with effective model predictions. We observe an attractive phase shift in the low-energy region of the $I=0$ channel and a repulsive phase shift in the $I=1$ channel. No evidence for a pentaquark bound state is found in either channel.