Doubly heavy baryons in Born-Oppenheimer EFT

We report on the recent progress on the computation of the doubly heavy baryon spectrum in effective field theory. The effective field theory is built upon the heavy-quark mass and adiabatic expansions. The potentials can be expressed as NRQCD Wilson loops with operator insertions. These are nonperturbative objects and so far only the one corresponding to the static potential has been computed with lattice QCD. We review the proposal for a parametrization of the potentials based in an interpolation between the shortand long-distance regimes. The long-distance description is obtained with a newly proposed Effective String Theory which coincides with the previous ones for pure gluodynamics but it is extended to contain a fermion field. We show the doubly heavy baryon spectrum with hyperfine contributions obtained using these parametrizations for the hyperfine potentials.

Mass spectrum of triply heavy baryon in the hypercentral quark model

In this study, we consider baryons as three-body bound systems according to hypercentral constituent quark model in configuration space and solve three-body Klein–Gordon equation. Then we analyze perturbative spin-dependent and isospin-dependent interaction effects. To find the analytical solution, we used screened potential and calculate the eigenfunctions and eigenvalues of triply heavy baryons by using Nikiforov–Uvarov method. We compute the ground and excited state masses of triply heavy baryons with quantum numbers [Formula: see text], [Formula: see text], [Formula: see text] via constituent quark model approach.

Calculation of doubly heavy baryons decay

We calculated a subclass of four nonleptonic two-body weak decays of the double charm baryon ground states Ξcc++. Nonleptonic decays can be dividedinto two group: factorizable and nonfactorizable decays. The first one can be easily calculated from first principles. Therefore, its good example understands all pros and cons of a model. We focused on a weak two-body nonleptonic decay consists only fromthe factorizing contribution precluding a contamination from W-exchange. We use the covariant confined quark model previously developed by us to calculate the various helicity amplitudes which describe the dynamics of the transition induced by the Cabibbo-favored effective currents. Achievement of CCQM is that only size parameter Λvarying can describe all tree diagrams of nonleptonic decay. We then proceed to calculate the rates of the decay. The rates, branching ratios and helicity amplitude were calculated using dimensionless invariant form factors. Also, we calculated leptonic constant for scalar and vector mesons which has good agreement with experimental data. There isn’t any experimental data about the decay so we waiting for new experimental observation in the heavy baryon sector.

The axion-baryon coupling in SU(3) heavy baryon chiral perturbation theory

In the past, the axion-nucleon coupling has been calculated in the framework of SU(2) heavy baryon chiral perturbation theory up to third order in the chiral power counting. Here, we extend these earlier studies to the case of heavy baryon chiral perturbation theory with SU(3) flavor symmetry and derive the axion coupling to the full SU(3) baryon octet, showing that the axion also significantly couples to hyperons. As studies on dense nuclear matter suggest the possible existence of hyperons in stellar objects such as neutron stars, our results should have phenomenological implications related to the so-called axion window.

Universal behavior of mass gaps existing in the single heavy baryon family

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 $$\lambda $$ 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 $$\Xi _b^0$$ Ξ b 0 baryons which are still missing in the experiment. For completeness, we also discuss the mass gaps of these $$\rho $$ ρ -mode excited single heavy flavor baryons.