Hadrons made by diquark-antidiquark pairs(tetraquarks)are held together by QCD forces in an overall color singlet.As stated in the original proposals and similarly to baryons and qq mesons,tetraquarks form complete mu...Hadrons made by diquark-antidiquark pairs(tetraquarks)are held together by QCD forces in an overall color singlet.As stated in the original proposals and similarly to baryons and qq mesons,tetraquarks form complete multiplets of the flavour symmetry,SU(3)f.展开更多
In a research article appeared in this journal[1], the LHCb Collaboration has presented an extraordinary result on the mass spectrum of J/ψ-pairs produced in proton-proton high energy collisions. The spectrum shows: ...In a research article appeared in this journal[1], the LHCb Collaboration has presented an extraordinary result on the mass spectrum of J/ψ-pairs produced in proton-proton high energy collisions. The spectrum shows: a narrow structure around 6:9 GeV matching the lineshape of a resonance and a broad structure just above twice the J/ψ mass. In the same region, more resonances may be present, not clearly distinguished within present statistics(see Fig. 1). A new spectroscopy is waiting for us, that of fully charm tetraquarks, which parallels the spectroscopy of charmonia revealed by the J/ψ discovery of 1974.展开更多
文摘Hadrons made by diquark-antidiquark pairs(tetraquarks)are held together by QCD forces in an overall color singlet.As stated in the original proposals and similarly to baryons and qq mesons,tetraquarks form complete multiplets of the flavour symmetry,SU(3)f.
文摘In a research article appeared in this journal[1], the LHCb Collaboration has presented an extraordinary result on the mass spectrum of J/ψ-pairs produced in proton-proton high energy collisions. The spectrum shows: a narrow structure around 6:9 GeV matching the lineshape of a resonance and a broad structure just above twice the J/ψ mass. In the same region, more resonances may be present, not clearly distinguished within present statistics(see Fig. 1). A new spectroscopy is waiting for us, that of fully charm tetraquarks, which parallels the spectroscopy of charmonia revealed by the J/ψ discovery of 1974.
