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.

Weak decays of bottom-charm baryons: $$\mathcal {B}_{bc}\rightarrow \mathcal {B}_bP$$

After the discovery of the double-charm baryon $$\Xi _{cc}^{++}$$ Ξ cc + + by LHCb, one of the most important topics is to search for the bottom-charm baryons which contain a b quark, a c quark and a light quark. In this work, we study the two-body non-leptonic weak decays of a bottom-charm baryon into a spin-1/2 bottomed baryon and a light pseudoscalar meson with the short-distance contributions calculated under the factorization hypothesis and the long-distance contributions considering the final-state-interaction effects. The branching fractions of all fifty-seven decay channels are estimated. The results indicate that $$\Xi _{bc}^+\rightarrow \Xi _b^0\pi ^+$$ Ξ bc + → Ξ b 0 π + , $$\Xi _{bc}^{0}\rightarrow \Xi _{b}^{-}\pi ^+$$ Ξ bc 0 → Ξ b - π + and $$\Omega _{bc}^0\rightarrow \Omega _b^-\pi ^+$$ Ω bc 0 → Ω b - π + decay modes have relatively large decay rates and thus could be used to experimentally search for the bottom-charm baryons. The topological diagrams and the SU(3) symmetry of bottom-charm baryon decays are discussed.

Novel Ideas in Nonleptonic Decays of Double Heavy Baryons

The recent discovery of double charm baryon states by the LHCb Collaborarion and their high precision mass determination calls for a comprehensive analysis of the nonleptonic decays of double and single heavy baryons. Nonleptonic baryon decays play an important role in particle phenomenology since they allow for studying the interplay of long and short distance dynamics of the Standard Model (SM). Furthermore, they allow one to search for New Physics effects beyond the SM. We review recent progress in experimental and theoretical studies of the nonleptonic decays of heavy baryons with a focus on double charm baryon states and their decays. In particular, we discuss new ideas proposed by the present authors to calculate the W-exchange matrix elements of the nonleptonic decays of double heavy baryons. An important ingredient in our approach is the compositeness condition of Salam and Weinberg, and an effective implementation of infrared confinement both of which allow one to describe the nonperturbative structure of baryons composed of light and heavy quarks. Furthermore, we discuss an ab initio calculational method for the treatment of the so-called W-exchange diagrams generated by W ± boson exchange between quarks. We found that the W ± -exchange contributions are not suppressed in comparison with the tree-level (factorizing) diagrams and must be taken into account in the evaluation of matrix elements. Moreover, there are decay processes such as the doubly Cabibbo-suppressed decay Ξ c + → p ϕ recently observed by the LHCb Collaboration, which is contributed to only by one single W-exchange diagram.

Resolving the SELEX–LHCb double-charm baryon conflict: the impact of intrinsic heavy-quark hadroproduction and supersymmetric light-front holographic QCD

In this paper we review the hadroproduction mechanisms of doublecharm baryons for the different experimental environments and reinterpret the SELEX and LHCb results.