Speaker
Yan Lyu
Description
The doubly charmed tetraquark $T^+_{cc}$ recently discovered by the LHCb Coll. is studied by using (2+1)-flavor lattice QCD simulations with nearly physical pion mass $m_\pi=146$ MeV. The interaction between $D^*$ and $D$ in the isoscalar and $S$-wave channel extracted from the hadronic spacetime correlation by the HAL QCD method is attractive and leads to a near-threshold virtual state with a pole position $E_\text{pole}\simeq-59$ keV. The virtual state is shown to evolve into a loosely bound state as $m_\pi$ decreases to its physical value by using a potential modified to $m_\pi=135$ MeV based on the pion-exchange interaction. Such a potential is also able to describe the LHCb data on the $D^0D^0\pi^+$ mass spectrum.
