$DK$ and $D^* K$ scattering near threshold

TL;DR

This study investigates charm-strange meson states near thresholds using lattice QCD, identifying bound states and resonances consistent with experimental observations.

Contribution

It provides the first lattice QCD determination of the scattering amplitudes and nature of several $D_s$ states near thresholds, including bound states and resonances.

Findings

$D^*_{s0}(2317)$ and $D_{s1}(2460)$ are bound states below threshold.

$D_{s1}(2536)$ and $D^*_{s2}(2573)$ are narrow resonances near experimental masses.

Used advanced lattice techniques to determine scattering amplitudes.

Abstract

We study the three $D_s$ quantum channels $J^P = 0^+$, $1^+$ and $2^+$ where experiments have identified the charm-strange states $D^*_{s0} (2317)$, $D_{s1}(2460)$, $D_{s1}(2536)$ near the $DK$ and $D^*K$ thresholds, and $D^*_{s2}(2573)$. We consider correlation functions for sets of $\overline q q$ operators and, for $J^P = 0^+$, $1^+$, also the $DK$ and $D^*K$ meson-meson interpolators and determine for these cases values of the elastic scattering amplitude. Constructing the full set of correlators requires propagators which connect any pair of lattice sites. For one ensemble of gauge configurations ($32^3\times 64$, $m_\pi\approx 156$ MeV) a stochastic distillation variant is employed and for another ensemble ($16^3\times 32$, $m_\pi\approx 266$ MeV) we use the full distillation method. Both, $D^*_{s0} (2317)$ and $D_{s1}(2460)$, are found as bound states below threshold, whereas $D_{s1}(2536)$, and $D^*_{s2}(2573)$ are identified as narrow resonances close to the experimental masses.