Quark-diquark Model Of Baryons Research Articles

NLO QCD corrections to triply heavy baryon fragmentation function considering the effect of nonperturbative dynamics of baryon bound states

Using a quark-diquark model of baryons and by working in the framework of perturbative quantum chromodynamics we present, for the first time, the next-to-leading-order (NLO) corrections to the fragmentation process of a heavy quark into a ground state triply heavy baryon. For a complete analysis, we also study the effect of nonperturbative dynamic of baryon bound state on the extracted fragmentation functions considering a typical wave function which is different from the Dirac-delta function that was applied in all previous works. Our results show that the NLO corrections are significant, while the effect of the baryonic wave function is of minor importance.

Polarized heavy baryon production in quark-diquark model considering two different scenarios

At sufficiently large transverse momentum, the dominant production mechanism for heavy baryons is actually the fragmentation. In this work, we first study the direct fragmentation of a heavy quark into the unpolarized triply heavy baryons in the leading order of perturbative QCD. In a completely different approach, we also analyze the two-stage fragmentation of a heavy quark into a scalar diquark followed by the fragmentation of such a scalar diquark into a triply heavy baryon: quark-diquark model of baryons. The results of this model are in acceptable agreement with those obtained through a full perturbative regime. Relying on the quark-diquark model and considering two different scenarios we determine the spin-dependent fragmentation functions of polarized heavy baryons in such a way that a vector or a pseudoscalar heavy diquark is an intermediate particle between the initial heavy quark and the final state baryon.

Diquark Fragmentation Contribution in Λ b Production

In the framework of the quark-diquark model of baryons, Λ b can be considered as b constituent quark an ud constituent diquark. In this study, we investigate the effect ud scalar diquark fragmentation into Λ b , therefor we calculate frgmentation functions of b quark and ud diquark into Λ b baryon through the use of perturbative QCD. In the next stage, throuth the use of the obtained fragmentation functions, we calculate the total fragmentation probabilities and average fragmentation parameters for b→Λ b and u d→Λ b . Finally, the inclusive cross section of Λ b baryon in electron-positron annihilation in ALEPH experiment is calculated with regard to ud diquark fragmentation contribution.

Inclusive Production Λ c in the e + e − - Annihilation

In the framework of the quark-diquark model of baryons, Λ c can be considered as constituent c quark and ud diquark. In hadronizasion process baryon Λ c can be produced from ud scalar diquark and c quark fragmentation. So in this work, in the lowest order of perturbative QCD, fragmentation functions c → Λ c and ud → Λ c are calculated and finally in the electron-positron annihilation in LEP, the inclusive cross section production of Λ c is calculated about pole of z 0.

Heavy quark fragmentation into double heavy baryons in the quark-diquark model

In the framework of nonrelativistic QCD and the quark-diquark model of baryons we have obtained the fragmentation functions for heavy quarks that split into spin- 1 2 and spin- 3 2 double heavy baryons. We predict the production rates as well as the shape of the energy spectra for cc- and bc-baryons in the region of the Z 0 peak at the LEP collider.

Charmed baryons in a quark-diquark model

A quark-diquark model of baryons is generalized to include charmed baryons within the framework of the broken-symmetry groupsSU8 andSU8 ×O3. Mass relations are obtained for the baryons belonging to the lowest-lying level ofSU8, and some qualitative features of the higher levels are given.