Speaker
Description
In this talk I will present preliminary results from an ongoing study of coupled $DD^* - D^*D^*$ scattering on the lattice. To obtain the finite-volume spectrum of the system we incorporate a variety of scattering interpolators in both channels, in addition to a local diquark-antidiquark operator, whose role in determining the energies of excited states for this system has recently emerged. The spectrum is obtained using two ensembles, generated by the CLQCD collaboration, with a pion mass $m_{\pi} \approx 305$ MeV at two volumes: $L=32, 48$. In the subsequent scattering analysis we employ the two-body adapted Finite-Volume Unitarity (FVU) quantization condition to constrain infinite-volume interactions in the system. The left-hand branch cuts in direct- and cross-channel scattering amplitudes, induced by the one-pion exchange, are explicitly addressed in the quantization condition. Finally, preliminary fits to the lattice spectra, using a variety of parametrizations of low-energy contact interactions, are shown.