| With a nonrelativistic constituent quark model,we studied the mass spectra of the all-heavy tetraquarks and ?QQQ(Q=s,c,b)states up to the N=2 shell,respectively.Furthermore,the decay properties for the ?QQQ resonances within the N=2 shell are evaluated by using the masses and wave functions obtained from the potential model.Our main results as follows:(?)By studying the all-heavy tetraquarks,we find that:(?)All-heavy cccc,bbbb,bbcc/ccbb,bccc/ccbc,bcbb/bbbc,and bcbc systems have masses above the corresponding two meson decay thresholds,and these states may easily decay into the two mesons channels via the quark rearrangement.This implies that narrow all-heavy tetraquark states may not exist in reality.(?)The linear confining potential contributes large positive energies to the eigenvalues of the ground states of these tetraquark systems and it is crucial to include it in calculations.(?)By studying the ? baryon,we find that:(?)The ?(2012)resonance is most likely to be the spin-parity JP=3/2-1P-wave state ?(12P3/2-).Both the mass and decay properties predicted in theory are consistent with the observations.The ?(2012)resonance may be observed in the radiative decay channel ?(1672)?.The other 1P-wave state ?(12P1/2-)is also a narrow state with a width of?12 MeV.If more data were accumulated,the ?(12P1/2-)state may be clearly established in the ?-K0 and?0K-invariant,mass dist,ributions around 1.95 GeV.(ii)The ?(2250)resonance may be a good candidate for the ?(14D5/2+).With this assignment both the mass and strong decay properties of ?(2250)can be reasonably understood in the quark model.It should be mentioned that the ?(14D5/2-)state may highly overlap with the ?(12D3/2+)state.This state might be a narrow state with a width of several MeV and mainly decays into?K and ?(1530)K channels.The measurements of the partial width ratio between these two channels might be helpful to distinguish the ?(12D3/2+)state from the ?(14D5/2+)state in experiments.Furthermore,the ?(12D3/2+)state might be established in the radiative decay channel ?(2012)?.(?)For the other 1D-wave states,it is found that both ?(14D7/2+)and ?(14D1/2+)dominantly decay into the ?K channel with a width of?40 MeV,they may be established in the ?K invariant mass spectrum around 2.3 GeV and 2.1 GeV,respectively.The ?(12/D5/2+)state dominantly decay into the?(1530)K channel with a narrow width of 19 MeV,it is worth to looking for in the?(1530)K invariant mass spectrum around 2.3 GeV.The ?(14D3/2+)state has a width of?30 MeV,it mainly decays into both ?K and ?(1530)K channels.To look for this missing state,both ?K and ?(1530)K invariant mass distributions around 2.2 GeV are worth observing in future experiments.(?)For the 2S-wave states ?(22S1/2+)and?(24S3/2+)might be very narrow state with a width of several MeV.The mass splitting between these two states is about 70 MeV.They may be established in the ?(1530)K invariant mass spectrum around 2.2 GeV.The ?(22S1/2+)state mightbe established with the ?(2012)? final state.(?)By studying the ?ccc and ?bbb baryons,we find that:(?)For the ground states?ccc and ?bbb,our predicted masses are 4828 MeV and 14432 MeV,respectively.while for the excited states,Our predicted masses range for the 1P-,1D-,and 2S-wave?ccc,baryons are 5.14-5.16 GeV,5.35-5.43 GeV,and 5.28-5.38 GeV respectively;and predicted masses range for the 1 P-,ID-,and 2S-wave Qbbb baryons are 14.77-14.78 GeV,14.97-15.02 GeV,and 14.85-14.96 GeV respectively.(?)For the ?ccc sector,the transition rates for 1P?1S might be sizeable,the partial widths are about several KeV;the transition rates for the E1 dominant decay processes 12D3/2+?12P1/2+,3/2+,12D5/2+?12P3/2+,22S1/2+?12-P1/2+,3/2+are relatively large,their partial widths are predicted to be about 10s KeV.For the ?bbb sector,the partial widths of the corre-sponding transitions mentioned above are about one or two order of magnitude smaller than those for the ?ccc sector. |
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