Longitudinal spin transfer coefficient to and hyperons in semi-inclusive deep-inelastic scattering

This dissertation presents a study of the spin-dependent production of the hyperon and the mechanisms of quark fragmentation, with a particular focus on data obtained from the HERMES experiment at DESY. The research explores the role of longitudinal spin effects in semi-inclusive deep-inelastic scattering. For that, the beam-spin induced polarization of and hyperons produced in deep-inelastic scattering of longitudinally polarized leptons (positrons or electrons) from unpolarized nucleons is being investigated using data collected by the HERMES experiment at a lepton beam energy of 27. 6 GeV. The beam-to-hyperon spin-transfer coefficients D₋ₗ and D₋ₙ, i. e. , transverse and along the hyperon momentum direction, are studied as function of the relevant kinematic variables. A novel extraction method, which does not rely on precise detector-response simulations, has been developed and is presented here. Advanced data analysis techniques are employed to mitigate systematic uncertainties arising from experimental acceptance and detector inefficiencies. This approach is applied for the first time by taking advantage of the regular reversal of the HERA lepton beam helicity at the HERMES experiment.