6533b827fe1ef96bd12864fd

RESEARCH PRODUCT

Improved variables for measuring theΛbpolarization

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description

We discuss a few possible strategies for measuring the polarization of the {Lambda}{sub {ital b}} baryons produced in {ital e}{sup +}{ital e}{sup {minus}} annihilation at the {ital Z} resonance through their inclusive semileptonic decays. After reviewing the existing methods, an extension is proposed, based on the ratio of the averages of the squared electron and neutrino energies, including both perturbative and nonperturbative corrections. This variable minimizes the statistical error on the {Lambda}{sub {ital b}} polarization, while keeping the systematic theoretical errors at the level of 1{endash}2{percent}. A number of other polarization-sensitive variables are also discussed, such as averages of ratios of the electron and neutrino energies and the distribution in the difference between the electron and neutrino rapidities. {copyright} {ital 1996 The American Physical Society.}