Ja n 19 97 Λ and Λ Polarization in Lepton Induced Processes

Lambda Polarization in Lepton Induced Reactions

Different phenomenological approaches for Λ and Λ polarization in polarized semi-inclusive deep inelastic scattering and electron-positron annihilation at Z pole are considered. Current and future experiments will soon provide accurate enough data to study spin phenomena in these reactions and distinguish between various models. Talk given at the SPIN-97 VII Workshop on High Energy Spin Physics...

Ja n 19 98 Λ b POLARIZATION IN THE Z BOSON DECAYS

Ja n 20 01 Rare Λ b → Λ l + l − Decays with Polarized Λ

We investigate the rare baryonic exclusive decays of Λb → Λll (l = e, μ, τ) with polarized Λ. Under the approximation of the heavy quark effective theory (HQET), in the standard model we derive the differential decay rates and various polarization asymmetries by including lepton mass effects. We find that with the long-distance effects the decay branching ratios are 5.3× 10 for Λb → Λll (l = e,...

The contribution of Σ ∗ → Λ π to measured Λ polarization †

Calculations of the polarization of Λ and ¯ Λ particles after fragmentation of a polarized quark produced in processes like Z-decay and deep inelas-tic polarized lepton scattering must include Λ and ¯ Λ produced as decay products of Σ 0 and Σ * as well as those produced directly. These decay contributions are significant and not feasibly included in theoretical calculations based on QCD without...

Λ , Λ polarization and spin transfer in lepton deep - inelastic scattering

The flavor and helicity distributions of the Λ and Λ hyperons for both valence and sea quarks are calculated in a perturbative QCD (pQCD) based model. We relate these quark distributions to the fragmentation functions of the Λ and Λ, and calculate the z-dependence of the longitudinal spin transfer to the Λ and Λ in lepton deepinelastic scattering (DIS). It is shown that the spin transfer to the...