Spectroscopy and Regge trajectories of heavy baryons in the relativistic quark-diquark picture

Abstract

Mass spectra of heavy baryons are calculated in the heavy-quark-light-diquark picture in the framework of the QCD-motivated relativistic quark model. The dynamics of light quarks in the diquark as well as the dynamics of the heavy quark and light diquark in the baryon are treated completely relativistically without application of nonrelativistic v/c and heavy quark 1/m Q expansions. Such approach allows us to get predictions for the heavy baryon masses for rather high orbital and radial excitations. On this basis the Regge trajectories of heavy baryons for orbital and radial excitations are constructed, and their linearity, parallelism, and equidistance are verified. The relations between the slopes and intercepts of heavy baryons are considered and a comparison of the slopes of Regge trajectories for heavy baryons and heavy-light mesons is performed. All available experimental data on heavy baryons fit nicely to the constructed Regge trajectories. The possible assignment of the quantum numbers to the observed excited charmed baryons is discussed.

Very narrow excited Ωc baryons

“…They, too, consider only excitations in which the (ss) diquark remains intact, with orbital angular momentum 1 with respect to the heavy quark. Most of the other excited Ω c predictions mentioned above are clustered somewhat below the spin-weighted average based on our assignments in Table I.The possibility thus must be considered that not all of the states reported by LHCb are P -wave excitations of the (ss) diquark with respect to the charmed quark [10,[31][32][33]). Indeed, Ref.…”

“…Predictions of ∼ 3000 ± 40 MeV for the negative-parity Ω c states, and an analogous range for the Ω b states, have been made by several authors [10,[15][16][17][18][19][20][21][22][23][24][25][26][27]. (The last paper treats only 2S levels, identifying the states at 3066, 3119 MeV as candidates for J P = 1/2 + , 3/2 + , respectively.…”

“…The possibility thus must be considered that not all of the states reported by LHCb are P -wave excitations of the (ss) diquark with respect to the charmed quark [10,[31][32][33]). Indeed, Ref.…”

“…We adopt the notation of Ref. [10], who have predictions for the masses of these states which we shall discuss presently. The spin-dependent potential between a heavy quark Q and the (ss) spin-1 diquark is…”

“…An initial effort to assign J P values to the five states made use of the linearized equations (7)(8)(9)(10)(11). With a 1 and a 2 extrapolated from Ref.…”