New spectrum of negative-parity doubly charmed baryons: Possibility of two quasistable states

Abstract

The discovery of Ξ ++ cc by the LHCb Collaboration triggers predictions of more doubly charmed baryons. By taking into account both the P -wave excitations between the two charm quarks and the scattering of light pseudoscalar mesons off the ground state doubly charmed baryons, a set of negative-parity spin-1/2 doubly charmed baryons are predicted already from a unitarized version of leading order chiral perturbation theory. Moreover, employing heavy antiquark-diquark symmetry the relevant low-energy constants in the next-to-leading order are connected with those describing light pseudoscalar mesons scattering off charmed mesons, which have been well determined from lattice calculations and experimental data. Our calculations result in a spectrum richer than that of heavy mesons. We find two very narrow J P = 1/2 − Ω P cc , which very likely decay into Ωccπ 0 breaking isospin symmetry. In the isospin-1/2 Ξ P cc sector, three states are predicted to exist below 4.2 GeV with the lowest one being narrow and the other two rather broad. We suggest to search for the Ξ P cc states in the Ξ ++ cc π − mode. Searching for them and their analogues are helpful to establish the hadron spectrum.

Light pseudoscalar meson and doubly charmed baryon scattering lengths with heavy diquark-antiquark symmetry

“…In Ref. [4], a set of negative-parity spin-1/2 doubly charmed baryons are predicted from a unitarized version of ChPT combining with HDA symmetry. In this work, we calculate the scattering lengths of the B cc φ and B * cc φ in the heavy baryon chiral perturbation theory (HBChPT) to the next-to-next-to-leading order.…”

The $Ω_{cc}$ resonances with negative parity in the chiral constituent quark model

“…In any case, we can conclude that the Ω cc resonances should lie at a energy below 4200 MeV in both the compact five-quark model (present) and the meson-baryon model [61].…”

“…The corresponding obtained energies for the P -wave Ω cc in a three-quark picture are around 4000 − 4200 MeV in most of the literatures, and one may note that in Ref. [61], the S-wave interactions between pseudo-Nambu-Goldstone bosons (π, K and η) and the The ten physical pentaquark states obtained in present model, line three shows the energies for the states |i ′ (in MeV), and lines four to ten are the corresponding probability amplitudes. J P = 1/2 + ground state doubly charmed baryons in the energy region around the corresponding thresholds are investigated, two quasistable narrow J P = 1/2 − Ω cc are predicted to lie at the energy below 4200 MeV, and their strong decay mode is predicted to be only the Ω cc π 0 , which is isospin breaking channel.…”

“…Up to now, there are no solid experimental data for the Ω cc resonances, while theoretical investigations on the doubly heavy baryon resonances have been intensively taken using various of approaches, such as the constituent quark model [9,10,[56][57][58][59][60], QCD sum rules [17], chiral perturbation theory [20][21][22], the unitarized coupled channel approach [61], and the lattice QCD calculations [25], etc. The corresponding obtained energies for the P -wave Ω cc in a three-quark picture are around 4000 − 4200 MeV in most of the literatures, and one may note that in Ref.…”

Towards a heavy diquark effective theory for weak decays of doubly heavy baryons

“…According to Refs. [36,37,43], there are three different momentum scales display in the dynamics of a doubly heavy baryon: the heavy quark mass m Q , its typical 3-momentum m Q v in the rest frame of baryon, and its typical kinetic energy m Q v 2 . The spatial size of the two heavy quarks can be estimated to be r Q Q ∼ 1/m Q v, while the distance between one of the heavy quarks and the light quark is approximately r Qq ∼ 1/ QC D .…”