Establishing low-lying doubly charmed baryons

Abstract

We systematically study the S -wave doubly charmed baryons using the method of QCD sum rules. Our results suggest that the Ξ ++ cc recently observed by LHCb can be well identified as the S -wave Ξ cc state of J P = 1/2 + . We study its relevant Ω cc state, whose mass is predicted to be around 3.7 GeV. We also systematically study the P-wave doubly charmed baryons, whose masses are predicted to be around 4.1 GeV. Especially, there can be several excited doubly charmed baryons in this energy region, and we suggest to search for them in order to study the fine structure of the strong interaction.

Masses of the Doubly-heavy Tetraquarks in a Constituent Quark Model

“…With the recent discovery of the doubly charmed baryon Ξ ++ cc [1,2] and its decay [3], there is currently a great interest in doubly charmed hadrons [4][5][6][7]. While there were previous reports on the observation of a doubly charmed baryon [8], the present observation marks the first unambiguous observation of the doubly heavy baryon with the measured mass different from the earlier claim.…”

Masses of doubly heavy-quark baryons in an extended chromomagnetic model

“…Note that, with two identical quarks, the pair parameters m qq and v qq only appear in the combination m qq + v qq /3 in the mass formulas (33) and (29). So we can only determine the value m ss + v ss /3 from the experimental data.…”

“…± 0.14(Λ + c ) MeV. In contrast to the rarity of the experimental observation of the doubly heavy baryons, there is a vast literature of theoretical studies concerning the doubly and even triply heavy baryons with different approaches, including quark models [12][13][14][15][16][17][18][19][20][21][22][23][24], QCD sum rules [25][26][27][28][29], lattice QCD [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45], the bag model [46], heavy-quark effective theory [47], heavy-quark spin symmetry [48,49], effective field theory with potential nonrelativistic QCD [50,51], the Feynman-Hellmann theorem [52], variational method [53], the Skyrmion model [54] and the Regge phenomenology [55,56].…”

Weak decays of doubly heavy baryons: the $$1/2\rightarrow 1/2$$ 1 / 2 → 1 / 2 case

“…The doubly heavy baryon systems with the quark contents Q 1 Q 2 q with Q 1,2 = b, c and q = u, d, s have been studied extensively using various theoretical methods, such as quark models [43][44][45][46], the bag model [47], QCD sum rules [48], heavy quark effective theory [49,50], Lattice QCD simulation [51][52][53][54][55][56][57], etc. For cc , most predictions are in the range 3.5 to 3.7 GeV.…”