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

A. Airapetian, N. Akopov, M. Amarian, E. C. Aschenauer, H. Avakian, R. Avakian, A. Avetissian, B. Bains, C. Baumgarten, M. Beckmann, S. Belostotski, J. E. Belz, Th Benisch, S. Bernreuther, N. Bianchi, J. Blouw, H. Böttcher, A. Borissov, M. Bouwhuis, J. BrackS. Brauksiepe, B. Braun, B. Bray, S. Brons, W. Brückner, A. Brüll, E. E.W. Bruins, H. J. Bulten, G. P. Capitani, P. Carter, P. Chumney, E. Cisbani, G. R. Court, P. F. Dalpiaz, E. De Sanctis, D. De Schepper, E. Devitsin, P. K.A. De Witt Huberts, P. Di Nezza, M. Düren, A. Dvoredsky, G. Elbakian, J. Ely, A. Fantoni, A. Fechtchenko, M. Ferstl, K. Fiedler, B. W. Filippone, H. Fischer, B. Fox, J. Franz, S. Frullani, M. A. Funk, Y. Gärber, H. Gao, F. Garibaldi, G. Gavrilov, P. Geiger, V. Gharibyan, A. Golendukhin, G. Graw, O. Grebeniouk, P. W. Green, L. G. Greeniaus, C. Grosshauser, M. Guidal, A. Gute, V. Gyurjyan, J. P. Haas, W. Haeberli, O. Häusser, J. O. Hansen, M. Hartig, D. Hasch, F. H. Heinsius, R. Henderson, M. Henoch, R. Hertenberger, Y. Holler, R. J. Holt, W. Hoprich, H. Ihssen, M. Iodice, A. Izotov, H. E. Jackson, A. Jgoun, R. Kaiser, E. Kinney, M. Kirsch, A. Kisselev, P. Kitching, H. Kobayashi, N. Koch, K. Königsmann, M. Kolstein, H. Kolster, V. Korotkov, W. Korsch, V. Kozlov

Research output: Contribution to journalArticlepeer-review

46 Scopus citations


Spin transfer in deep-inelastic Λ 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 Λ has been extracted. The spin transfer along the Λ 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 Λ. 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 Λ spin content, and is consistent with the assumption of helicity conservation in the fragmentation process.

Original languageEnglish
Article number112005
Pages (from-to)1120051-1120057
Number of pages7
JournalPhysical review D
Issue number11
StatePublished - Dec 1 2001

ASJC Scopus subject areas

  • Nuclear and High Energy Physics


Dive into the research topics of 'Measurement of longitudinal spin transfer to Λ hyperons in deep-inelastic lepton scattering'. Together they form a unique fingerprint.

Cite this