Implications of the Z_(cs)(3985) and Z_(cs)(4000) as two different states  

Z_(cs)(3985)和Zcs(4000)作为两个不同态的推论

作　　者：Lu Meng Bo Wang Guang-Juan Wang Shi-Lin Zhu 孟璐;王波;王广娟;朱世琳(Institut für Theoretische Physik II,Ruhr-Universität Bochum,D-44780 Bochum,Germany;School of Physical Science and Technology,Hebei University,Baoding 071002,China;Advanced Science Research Center,Japan Atomic Energy Agency,Tokai,Ibaraki 319-1195,Japan;School of Physics and Center of High Energy Physics,Peking University,Beijing 100871,China)

机构地区：[1]Institut für Theoretische Physik II,Ruhr-Universität Bochum,D-44780 Bochum,Germany [2]School of Physical Science and Technology,Hebei University,Baoding 071002,China [3]Advanced Science Research Center,Japan Atomic Energy Agency,Tokai,Ibaraki 319-1195,Japan [4]School of Physics and Center of High Energy Physics,Peking University,Beijing 100871,China

出　　处：《Science Bulletin》2021年第20期2065-2071,M0003,共8页科学通报（英文版）

基　　金：supported by the National Natural Science Foundation of China(11975033 and 12070131001);funded by the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation,Project ID 196253076-TRR 110);supported by JSPS KAKENHI(20F20026)。

摘　　要：Recently,the hidden charm tetraquark states Z_(cs)(3985)and Z_(cs)(4000)with strangeness were observed by the BESⅢ and LHCb collaborations,respectively,which are great breakthroughs for exploring exotic quantum chromodynamics(QCD)structures.The first and foremost question is whether they are the same state.In this work,we explore the implications of the narrower state Z_(cs)(3985)in BESⅢ and the wider one Z_(cs)(4000)in LHCb as two different states.Within a solvable nonrelativistic effective field theory,we include the possible violations of heavy quark spin symmetry and SU(3)flavor symmetry in a comprehensive approach.If Z_(cs)(3985)and Z_(cs)(4000)are two different states,our results show that Z_(cs)(4000)/Z_(cs)(3985)is the pure(|D_(s)^(*)D>+/-|D_(s)D^(*)>)/√2 state,and the SU(3)flavor partner of Zc(3900)is Z_(cs)(4000)rather than the Z_(cs)(3985).Another two important consequences are the existence of a tensor D_(s)^(*)D^(*) resonance with mass about 4126 MeV and width 13 MeV,and the suppression of the decay mode Z_(cs)(3985)J/ψK.The two consequences can be tested in experiments and distinguish the two-state interpretation from the one-state scheme.最近,BSEⅢ和LHCb合作组在探索QCD奇特结构取得重大进展:分别发现了隐粲数并含有奇异数的Z_(cs)(3985)和Z_(cs)(4000).目前,最亟待回答也是最重要的问题是两个实验观测到的是否是同一个态.本文基于BSEⅢ窄宽度的Z_(cs)(3985)和LHCb宽宽度的Z_(cs)(4000)是两个态的前提,给出一系列推论.采用完全可解的非相对论有效场论,作者系统地考虑了重夸克对称性和SU(3)味道对称性可能的破缺效应.如果Z_(cs)(3985)和Z_(cs)(4000)是不同的态,本文的计算表明它们将是比较纯的(|D_(s)^(*)D>+/-|D_(s)D^(*)>)/√2的态,Z_(c)(3900)的SU(3)味道的伴随态是Z_(cs)(4000)而不是Z_(cs)(3985).此外,还有两个很重要的预言:(1)存在一个张量的D_(s)^(*)D的共振态,其质量约为4126 MeV,宽度为13 MeV;(2)Z_(cs)(3985)→J/ψK的衰变会被压低.这两个预言可以在未来的实验中检验,从而有助于确认BSEⅢ和LHCb合作组此次分别发现的态是同一个还是不同态的解释,哪种更合理.

关 键 词：TETRAQUARK Strangness Heavy quark spin symmetry Zcs states 

分 类 号：O572.33[理学—粒子物理与原子核物理]