Measurement of the longitudinal spin transfer to Λ and \(\bar{\varLambda}\) hyperons in polarised muon DIS

Abstract

The longitudinal polarisation transfer from muons to Λ and \(\bar{\varLambda}\)  hyperons, \(D_{LL}^{\varLambda(\bar{\varLambda})}\) , has been studied in deep-inelastic scattering off an unpolarised isoscalar target at the COMPASS experiment at CERN. The spin transfers to Λ and \(\bar{\varLambda}\)  produced in the current fragmentation region exhibit different behaviours as a function of x and x F . The measured x and x F dependences of D Λ LL are compatible with zero, while \(D_{LL}^{\bar{\varLambda}}\) tends to increase with x F , reaching values of 0.4–0.5. The resulting average values are D Λ LL = −0.012±0.047±0.024 and \(D_{LL}^{\bar{\varLambda}}\) = 0.249±0.056±0.049. These results are discussed in the frame of recent model calculations.

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Correspondence to G. K. Mallot.

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Alekseev, M., Alexakhin, V.Y., Alexandrov, Y. et al. Measurement of the longitudinal spin transfer to Λ and \(\bar{\varLambda}\) hyperons in polarised muon DIS. Eur. Phys. J. C 64, 171 (2009). https://doi.org/10.1140/epjc/s10052-009-1143-7

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PACS

  • 13.60.Rj
  • 13.87.Fh
  • 13.88.+e
  • 14.20.Jn