Semi-leptonic decays of charmed baryons

We present estimates of semi-leptonic decays of the charmed $\text{1+}\text{2}$ baryons, members of the SU(3) 3¹ and 6 multiplets, into ordinary $\text{1+}\text{2}\text{and}\text{3+}\text{2}$ baryons. We give general expressions for decay rates and the mass M(B⁺?) spectra. We relate the relevant form factors for the $\text{1+}\text{2}\text{→}\text{1+}\text{2}$ transitions to the electromagnetic ones by means of CVC and SU(4). The form factors for $\text{1+}\text{2}\text{→}\text{3+}\text{2}$ transitions are related through SU(4) to those measured in Δ production. We discuss the dependence of the results on the masses of charmed baryons. The $\text{1+}\text{2}\text{→}\text{1+}\text{2}$ and $\text{1+}\text{2}\text{→}\text{3+}\text{2}$ transitions turn out to be dominant for the decays of the multiplets 3¹ and 6, respectively. The partial lifetimes are O(10^?10 ? 10^?14) sec as the masses of the decaying baryons are varied from 2 to 2.9 GeV. Possible ways of getting an idea about the masses of the charmed baryons are given.     

Weak decays of charmed baryons

We use the quark model framework to calculate the weak decays of the lowest lying charmed baryons into ground state baryons and mesons. We present detailed results on the predicted flavour and multipole composition of the final state configurations which can be tested in the near future. For the decays 1/2⁺→1/2⁺+0^? we also give symmetry and current algebra estimates which we compare with the quark model results. Semileptonic branching ratios in charmed baryon decays are calculated to be of the order of ～5%. The total lifetime of charmed baryons is predicted to be ～7 10^?14 s which is 5–10 times smaller than the free quark model estimate.     

Non-leptonic weak decays of charmed baryons

It is shown that the ΔC _h=ΔS decays of a baryon sextuplet, triplet and singlet of SU (3), into meson and baryon, can provide simple tests of the iscspin and SU (3) transformation properties of the ΔC _h=ΔS non-leptonic interaction in the Glashow Iliopoulos-Maiani scheme.     

B decays to baryons

From inclusive measurements, it is known that about 7% of all B mesons decay into final states with baryons. In these decays, some striking features become visible compared to mesonic decays. The largest branching fractions come with quite moderate multiplicities of 3?C4 hadrons. We note that two-body decays to baryons are suppressed relative to three- and four-body decays. In most of these analyses, the invariant baryon?Cantibaryon mass shows an enhancement near the threshold. We propose a phenomenological interpretation of this quite common feature of hadronization to baryons.     

Preliminary estimate of branching ratios of weak hadronic decays of bottom baryons emitting charmless scalar mesons

In this paper we study one-dimensional static self-dual non-topological solitons in an Abelian-Higgs Chern–Simons model with a non-canonical kinetic term. We choose a scalar potential with a single minimum and present an analytical soliton solution which corresponds to an electrically charged lump-like soliton without total momentum and located in a region where the scalar field gets maximum. The solitonic boundary conditions impose a discontinuity on the electric field across the soliton line where, then, there is a linear charge density.     

Spectroscopy of charmed baryons

We have fitted the masses and elastic widths of the S=0 baryons in the context of the QCD-improved quark shell model. All states in theN=0, 1, 2 and 3 harmonic oscillator bands have been included. Three models for the decay of these states have been studied, and it is concluded that the usual spectator model for the decays must be modified. Many resonances in theN=2 and 3 bands were found to decouple from the πN channel, supporting a previous solution to the missing resonance puzzle. No evidence has been found for the tensor force, while conflicting data exist for the 3-body spin orbit term. We also have found evidence that the contact force varies with band. The (56,1^?) multiplet is lower than expected.     

Strange charmed baryons in QCD

QCD sum rules are used to predict the mass differences between strange and nonstrange single charmed baryons inSU (3) sextets 1/2⁺, 1/2^?, 3/2⁺ and antitriplet 1/2⁺ as well as the mass of the lowest nonstrange stateΣ _c ^++′ in the 3/2⁺ sextet. The mass difference obtained for the antitriplet 1/2⁺ is in a good agreement with the available experimental data.