Measurement of longitudinal spin transfer to Lambda hyperons in deep-inelastic lepton scattering

HERMES Collaboration

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47 Citations (Web of Science)

Abstract

Spin transfer in deep-inelastic Lambda electroproduction has been studied with the HERMES detector using the 27.6 GeV polarized positron beam in the DESY HERA storage ring. For an average fractional energy transfer [z] = 0.45, the longitudinal spin transfer from the virtual photon to the Lambda has been extracted. The spin transfer along the Lambda momentum direction is found to be 0.11+/-0.17(stat)+/-0.03(syst); similar values are found for other possible choices for the longitudinal spin direction of the Lambda. This result is the most precise value obtained to date from deep-inelastic scattering with charged lepton beams, and is sensitive to polarized up quark fragmentation to hyperon states. The experimental result is found to be in general agreement with various models of the Lambda spin content, and is consistent with the assumption of helicity conservation in the fragmentation process.
Original languageEnglish
Article number112005
Number of pages7
JournalPhysical Review D
Volume64
Issue number11
DOIs
Publication statusPublished - 1 Dec 2001
Externally publishedYes

Keywords

  • POLARIZED QUARK DISTRIBUTIONS
  • STRUCTURE-FUNCTION G(1)(P)
  • MUON SCATTERING
  • (LAMBDA)OVER-BAR POLARIZATION
  • Z-DECAYS
  • PROTON
  • DEUTERON
  • ASYMMETRIES
  • NUCLEON
  • BARYONS

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