Doubly-heavy tetraquark states ccu¯d¯and bbu¯d¯  

作　　者：Xiaoyun Chen Youchang Yang 陈晓云;杨友昌(College of Science,Jinling Institute of Technology,Nanjing 211169,China;Guizhou University of Engineering Science,Zunyi Normal University,China)

机构地区：[1]College of Science,Jinling Institute of Technology,Nanjing 211169,China [2]Guizhou University of Engineering Science,Zunyi Normal University,China

出　　处：《Chinese Physics C》2022年第5期129-139,共11页中国物理C（英文版）

基　　金：Partly supported by the National Natural Science Foundation of China(11847145,11865019)。

摘　　要：Inspired by the recent observation of a very narrow state,called T_(cc)^(+),by the LHCb collaboration,the possible bound states and low-lying resonance states of the doubly-heavy tetraquark states ccu¯d¯(Tcc)and bbu¯d¯(Tbb)are searched in the framework of a chiral quark model with an accurate few-body method,the Gaussian expansion method.The real scaling method is also applied to identify the genuine resonance states.In the calculation,the meson-meson structure,diquark-antidiquark structure,and their coupling are all considered.The numerical results show:(i)For T_(cc)and T_(bb),only I(J^(P))=0(1^(+))states are bound in different quark structures.The binding energy varies from a few MeV for the meson-meson structure to over 100 MeV for the diquark-antidiquark structure.For example,for T_(cc),in the meson-meson structure,there exists a weakly bound molecule DD^(∗)state around 3841.4 MeV,1.8 MeV below the D^(0)D^(∗+),which may be a good candidate for the observed state by LHCb;however in the diquark-antidiquark structure,a deeper bound state with mass 3700.9 MeV is obtained.When considering the structure mixing,the energy of system decreases to 3660.7 MeV and the shallow bound state disappears.(ii)Besides bound states,several resonance states for T_(QQ)(Q=c,b)with I(J^(P))=1(0^(+)),1(1^(+)),1(2^(+)),0(1^(+))are proposed.

关 键 词：TETRAQUARKS quark model real scaling method 

分 类 号：O57[理学—粒子物理与原子核物理]