摘要
The internal structures of J^(PC)=1^(--),(0,1,2)^(-+)charmonium-like hybrids are investigated under lattice QCD in the quenched approximation.We define the Bethe-Salpeter wave function(Φn(r))in the Coulomb gauge as the matrix element of a spatially extended hybrid-like operator(ccg)between the vacuum and n-th state for each J^(PC),with r being the spatial separation between a localized cc component and the chromomagnetic strength tensor.These wave functions exhibit some similarities for states with the aforementioned different quantum numbers,and their r-behaviors(no node for the ground states and one node for the first excited states)imply that r can be a meaningful dynamical variable for these states.Additionally,the mass splittings of the ground states and first excited states of charmonium-like hybrids in these channels are obtained for the first time to be approximately 1.2-1.4 GeV.These results do not support the flux-tube description of heavy-quarkonium-like hybrids in the Born-Oppenheimer approximation.In contrast,a charmonium-like hybrid can be viewed as a"color halo"charmonium for which a relatively localized color octet cc is surrounded by gluonic degrees of freedom,which can readily decay into a charmonium state along with one or more light hadrons.The color halo picture is compatible with the decay properties of Y(4260)and suggests LHCb and BelleⅡto search for(0,1,2)^(-+)charmonium-like hybrids inχ_(c0,1,2η) and J/ψω(φ)final states.
作者
Yunheng Ma
Wei Sun
Ying Chen
Ming Gong
Zhaofeng Liu
马运恒;孙玮;陈莹;宫明;刘朝峰(Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100049,China;School of Physics,University of Chinese Academy of Sciences,Beijing 100049,China;Thomas Jefferson National Accelerator Facility,12000 Jefferson Avenue,Newport News,VA 23606,USA)
基金
Supported by the National Key Research and Development Program of China(2017YFB0203202)
the Strategic Priority Research Program of Chinese Academy of Sciences(XDB34030302,XDC01040100)
the National Natural Science Foundation of China(11935017,11575196,11775229,12075253,12070131001)(CRC 110by DFG and NSFC)
supported by the CAS Center for Excellence in Particle Physics(CCEPP)
support of DOE(DE-AC05-06OR23177)。
