Using highly excited baryons to catch the quark mass
T. Van Cauteren, P. Bicudo, M. Cardoso, Felipe J. Llanes-Estrada
备注：
6 pages, 9 figures, To appear in the proceedings of the 19th International IUPAP Conference on Few-Body Problems in Physics; added acknowledgment, hyphenized author name
Chiral symmetry in QCD can be simultaneously in Wigner and Goldstone modes, depending on the part of the spectrum examined. The transition regime between both, exploiting for example the onset of parity doubling in the high baryon spectrum, can be used to probe the running quark mass in the mid-IR power-law regime. In passing we also argue that three-quark states naturally group into same-flavor quartets, split into two parity doublets, all splittings decreasing high in the spectrum. We propose that a measurement of masses of high-partial wave Delta* resonances should be sufficient to unambiguously establish the approximate degeneracy and see the quark mass running. We test these concepts with the first computation of the spectrum of high-J excited baryons in a chiral-invariant quark model.
In the framework of diquark model for production we discuss the yields and observation prospects for excited states of doubly heavy baryons at LHC kinematic conditions.
The yield of doubly charmed baryons with excited heavy diquark in $S$ wave and $P$ wave states has been estimated at LHC energies. The observation possibility of such baryons is discussed.
We calculate the mass and residue of the newly observed $Ω_c(3000)$ and $Ω_c(3066)$ states with quantum numbers $J^P = \frac{1}{2}^{-}$ and $\frac{3}{2}^{-}$ within QCD sum rules. Our predictions on masses are in good agreement with the experimental results.
In this paper, the mass spectra are obtained for doubly heavy $Ξ$ baryons, namely, $Ξ_{cc}^{+}$, $Ξ_{cc}^{++}$, $Ξ_{bb}^{-}$, $Ξ_{bb}^{0}$, $Ξ_{bc}^{0}$ and $Ξ_{bc}^{+}$. These baryons are consist of two heavy quarks($cc$, $bb$ and $bc$) with a light($d$ or $u$) quark. The ground, radial and orbital states are calculated in framework of Hypercentral constituent quark model with coul- omb plus linear potential. Our outcomes are also compared with other predictions, thus, the average possible range of excited states masses of these $Ξ$ baryons can be determined. The study of the Regge trajectori…
The mass and residues of the first radial and orbital excitations of $J=\frac{1}{2}$ baryons containing two heavy quarks (b or c) are calculated within the QCD sum rules method. In calculations, the general forms of the interpolating currents with symmetric and anti-symmetric forms with respect to the exchange of heavy quarks have been used. Our results on the spectroscopic parameters of doubly heavy baryons are compared with the predictions of other theoretical approaches.
We study the conjectured "Insensitivity to Chiral Symmetry Breaking" in the highly excited light baryon spectrum. While the experimental spectrum is being measured at JLab and CBELSA/TAPS, this insensitivity remains to be computed theoretically in detail. As the only existing option to have both confinement, highly excited states and chiral symmetry, we adopt the truncated Coulomb gauge formulation of QCD, considering a linearly confining Coulomb term. Adopting a systematic and numerically intensive variational treatment up to 12 harmonic oscillator shells we are able to access several angular…
Mass spectra of excited states of the singly charmed baryons are calculated using the hypercentral description of three body system. The baryon consist of a charm quark and light quarks (u, d and s) are studied in the framework of QCD motivated constituent quark model. The form of confinement potential is hyper coloumb plus power potential with potential index $ν$, varying from 0.5 to 2.0. The first order correction to the confinement potential is also incorporated in this approach. The radial as well as orbital excited state masses of $Σ_{c}^{++}, Σ_{c}^+, Σ_{c}^0, Ξ_c^+, Ξ_c^0, Λ_c^+, Ω_c^0$…
The parton model relations in conjunction with quark-hadron duality in deep inelastic scattering suggests an asymptotic dominance of quark-diquark type of baryonic excited states with a radial Regge uniformly distributed mass squared spectrum $M_{n}^2 = μ^2 n + M_0^2$. We argue that this points to a lineary quark-diquark confining potential. We analyze the radial ($n$) and angular-momentum ($J$) Regge trajectories for all light-quark states with baryon number one listed in the 2016 edition of the Particle Data Tables. The parameters of the mass squared trajectories are obtained by linear regre…
The masses of ground and excited states of $Ω_c^0$, $Ω_{cc}^+$ and $Ω_{ccc}^{++}$ baryons are calculated within the framework of Regge phenomenology. Here our attempt is to assign a possible spin-parity to these obtained masses. Our calculated masses in $(J,M^2)$ plane with both natural ($J^{P}$ = $1/2^{+}$, $3/2^{-}$, $5/2^{+}$, ....) and unnatural ($J^{P}$ = $3/2^{+}$, $5/2^{-}$, $7/2^{+}$, ....) spin-parities are in agreement with the experimental observations where available and reasonably close to other theoretical predictions. Further we fix the slope and intercept of each Regge line in …
The ground and first excited states of the decuplet baryons are studied using the two-point QCD sum rule approach. The mass and residue of these states are computed and compared with the existing experimental data and other theoretical predictions. The results for the masses of the ground state particles as well as the excited $ Δ$ and $ Σ^{*} $ states are in good consistency with experimental data. Our results on the excited $ Ξ^{*} $ and $ Ω^{-} $ states reveal that the experimentally poorly known $ Ξ(1950) $ and $ Ω^{-}(2250) $ can be assigned as the first excited states in $ Ξ^{*} $ and $ …
The mass gaps existing in the discovered single heavy flavor baryons are analyzed, which show some universal behaviors. Under the framework of a constituent quark model, we quantitatively explain why such interesting phenomenon happens, when these established excited heavy baryons are regarded as the $λ$-mode excitations. Based on the universal behaviors of the discussed mass gaps, we may have three implications including the prediction of the masses of excited $Ξ_b^0$ baryons which are still missing in the experiment. For completeness, we also discuss the mass gaps of these $ρ$-mode excited s…
We give heavy quark-diquark symmetry predictions for doubly heavy baryons and tetraquarks in light of the recent discovery of the $Ξ_{cc}^{++}$ by LHCb. For five excited doubly charm baryons that are predicted to lie below the $Λ_c D$ threshold, we give predictions for their electromagnetic and strong decays using a previously developed chiral Lagrangian with heavy quark-diquark symmetry. Based on the mass of the $Ξ_{cc}^{++}$, the existence of a doubly heavy bottom $I=0$ tetraquark that is stable to the strong and electromagnetic decays has been predicted. If the mass of this state is below 1…
The spectrum of excited baryons in the $N$ = 2 band is reanalys9 pagesed in the $1/N_c$ expansion method, with emphasis on hyperons. Predictions are made for the classification of these excited baryons into SU(3) singlets, octets and decuplets.
In this paper, decay widths of the doubly heavy baryons ($Ξ_{cc} ~\text{and} ~Ξ_{bc}$) production are theoritically calculated in the whole phase space through $W^+ \to Ξ_{cc}+ \bar{c}+\bar{s}$ and $W^+ \to Ξ_{bc}+ \bar{b}+\bar{s}$, within the framework of nonrelativistic QCD (NRQCD). Differential widths $dΓ/ds_{12}$, $dΓ/ds_{23}$, $dΓ/dcosθ_{12}$, and $dΓ/dcosθ_{13}$ are also given. In addition to the ordinary S wave contributions for the baryons, we specifically calculate P wave contributions as a comparison, namely the high excited states of the intermediate diquark, including $[^1P_1]$ and…
