Padmanath M, Prelovsek S
Helmholtz Institut Mainz, Staudingerweg 18, 55128 Mainz, Germany.
GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1, 64291 Darmstadt, Germany.
Phys Rev Lett. 2022 Jul 15;129(3):032002. doi: 10.1103/PhysRevLett.129.032002.
The doubly charm tetraquark with flavor ccu[over ¯]d[over ¯] and isospin I=0 is investigated by calculating the DD^{} scattering amplitude with lattice QCD. The simulation is done on CLS ensembles with dynamical u/d, s quarks and m_{π}≃280 MeV for two charm quark masses, one slightly larger and one slightly lower than the physical value. The scattering amplitudes for partial waves l=0, 1 are extracted near threshold via the Lüscher method by considering systems with total momenta PL/(2π)=0,1,sqrt[2],2 on two spatial volumes. A virtual bound state pole in the DD^{} scattering amplitude with l=0 is found 9.9_{-7.1}^{+3.6} MeV below the DD^{} threshold for the charm quark mass closer to the physical value. This pole is likely related to the doubly charm tetraquark discovered by LHCb less than 1 MeV below the D^{0}D^{+} threshold. Future lattice simulations closer to the continuum limit and physical quark masses would be valuable to establish this connection systematically.
通过用格点量子色动力学计算(DD^{})散射振幅，研究了味为(ccu\overline{d})且同位旋(I = 0)的双粲四夸克态。在具有动态(u/d)、(s)夸克且(m_{\pi}\simeq280) MeV的CLS系综上进行模拟，针对两个粲夸克质量，一个略大于物理值，一个略小于物理值。通过Lüscher方法，在两个空间体积上考虑总动量(P_{L}/(2\pi)=0,1,\sqrt{2},2)的系统，在阈值附近提取了(l = 0,1)分波的散射振幅。对于更接近物理值的粲夸克质量，在(DD^{})散射振幅中发现了一个(l = 0)的虚束缚态极点，位于(DD^{})阈值以下(9.9_{-7.1}^{+3.6}) MeV处。这个极点可能与LHCb发现的低于(D^{0}D^{ +})阈值不到(1) MeV的双粲四夸克态有关。未来更接近连续极限和物理夸克质量的格点模拟对于系统地建立这种联系将是有价值的。
