We calculate the masses of the QQqq(Q=c,b:q=u,d,s)tetraquark states with the aid of heavy diquark-antiquark symmetry(HDAS)and the chromomagnetic interaction(CMI)model.The masses of the highestspin(J=2)tetraquarks that...We calculate the masses of the QQqq(Q=c,b:q=u,d,s)tetraquark states with the aid of heavy diquark-antiquark symmetry(HDAS)and the chromomagnetic interaction(CMI)model.The masses of the highestspin(J=2)tetraquarks that have only the(QQ)(3):(qq)_(3).color structure are related with those of conventional hadrons using HDAS.Thereafter,the masses of their partner states are determined with the mass splittings in the CMI model.Our numerical results reveal that(i)the lightest ccnn(n=u,d)is an I(J^(P))=0(1^(+))state around 3929 MeV(53 MeV above the DD^(*) threshold),and none of the double-charm tetraquarks are stable;(ii)the stable double-bottom tetraquarks are the lowest 0(1^(+))bbin around 10488 MeV(≈116 MeV below the BB^(*)threshold)and the lowest 1/2(1^(+))bbns around 10671 MeV(≈20 MeV below the BB_(s)^(*)/B_(s)B^(*)threshold);and(iii)the two lowest bcnn tetraquarks,namely the lowest 0(0^(+))around 7167 MeV and the lowest 0(1)around 7223 MeV,are in the nearthreshold states.Moreover,we discuss the constraints on the masses of double-heavy hadrons.Specifically,for the lowest nonstrange tetraquarks,we obtain T_(cc)<3965 MeV,T_(bb)<10627 MeV,and T_(bc)<7199 MeV.展开更多
基金Supported by National Natural Science Foundation of China (11775130, 11775132, 11635009, 11325525, 11875179)Natural Science Foundation of Shandong Province (ZR2016AM16, ZR2017MA002)。
文摘We calculate the masses of the QQqq(Q=c,b:q=u,d,s)tetraquark states with the aid of heavy diquark-antiquark symmetry(HDAS)and the chromomagnetic interaction(CMI)model.The masses of the highestspin(J=2)tetraquarks that have only the(QQ)(3):(qq)_(3).color structure are related with those of conventional hadrons using HDAS.Thereafter,the masses of their partner states are determined with the mass splittings in the CMI model.Our numerical results reveal that(i)the lightest ccnn(n=u,d)is an I(J^(P))=0(1^(+))state around 3929 MeV(53 MeV above the DD^(*) threshold),and none of the double-charm tetraquarks are stable;(ii)the stable double-bottom tetraquarks are the lowest 0(1^(+))bbin around 10488 MeV(≈116 MeV below the BB^(*)threshold)and the lowest 1/2(1^(+))bbns around 10671 MeV(≈20 MeV below the BB_(s)^(*)/B_(s)B^(*)threshold);and(iii)the two lowest bcnn tetraquarks,namely the lowest 0(0^(+))around 7167 MeV and the lowest 0(1)around 7223 MeV,are in the nearthreshold states.Moreover,we discuss the constraints on the masses of double-heavy hadrons.Specifically,for the lowest nonstrange tetraquarks,we obtain T_(cc)<3965 MeV,T_(bb)<10627 MeV,and T_(bc)<7199 MeV.
