Measurement of longitudinal spin transfer to Lambda hyperons in deep-inelastic lepton scattering - art. no. 112005

Authors
Airapetian, A Akopov, N Amarian, M Aschenauer, EC Avakian, H Avakian, R Avetissian, A Bains, B Baumgarten, C Beckmann, M Belostotski, S Belz, JE Benisch, T Bernreuther, S Bianchi, N Blouw, J Bottcher, H Borissov, A Bouwhuis, M Brack, J Brauksiepe, S Braun, B Bray, B Brons, S Bruckner, W Brull, A Bruins, EEW Bulten, HJ Capitani, GP Carter, P Chumney, P Cisbani, E Court, GR Dalpiaz, PF De Sanctis, E De Schepper, D Devitsin, E Huberts, PKAD Di Nezza, P Duren, M Dvoredsky, A Elbakian, G Ely, J Fantoni, A Fechtchenko, A Ferstl, M Fiedler, K Filippone, BW Fischer, H Fox, B Franz, J Frullani, S Funk, MA Garber, Y Gao, H Garibaldi, F Gavrilov, G Geiger, P Gharibyan, V Golendukhin, A Graw, G Grebeniouk, O Green, PW Greeniaus, LG Grosshauser, C Guidal, M Gute, A Gyurjyan, V Haas, JP Haeberli, W Hausser, O Hansen, JO Hartig, M Hasch, D Heinsius, FH Henderson, R Henoch, M Hertenberger, R Holler, Y Holt, RJ Hoprich, W Ihssen, H Iodice, M Izotov, A Jackson, HE Jgoun, A Kaiser, R Kinney, E Kirsch, M Kisselev, A Kitching, P Kobayashi, H Koch, N Konigsmann, K Kolstein, M Kolster, H Korotkov, V Korsch, W Kozlov, V Kramer, LH Krivokhijine, VG Kurisuno, M Kyle, G Lachnit, W Lenisa, P Lorenzon, W Makins, NCR Manaenkov, SI Martens, FK Martin, JW Masoli, F Mateos, A McAndrew, M McIlhany, K McKeown, RD Meissner, F Menden, F Metz, A Meyners, N Mikloukho, O Miller, CA Miller, MA Milner, R Most, A Muccifora, V Mussa, R Nagaitsev, A Naryshkin, Y Nathan, AM Neunreither, F Niczyporuk, JM Nowak, WD Nupieri, M O'Neill, TG Openshaw, R Ouyang, J Owen, BR Papavassiliou, V Pate, SF Pitt, M Potashov, S Potterveld, DH Rakness, G Reali, A Redwine, R Reolon, AR Ristinen, R Rith, K Rossi, P Rudnitsky, S Ruh, M Ryckbosch, D Sakemi, Y Savin, I Scarlett, C Schmidt, F Schmitt, H Schnell, G Schuler, KP Schwind, A Seibert, J Shibata, TA Shibatani, K Shin, T Shutov, V Simani, C Simon, A Sinram, K Slavich, P Spengos, M Steffens, E Stenger, J Stewart, J Stosslein, U Sutter, M Tallini, H Taroian, S Terkulov, A Thomas, E Tipton, B Tytgat, M Urciuoli, GM van den Brand, JFJ van der Steenhoven, G van de Vyver, R van Hunen, JJ Vetterli, MC Vikhrov, V Vincter, MG Visser, J Volk, E Wander, W Wendland, J Williamson, SE Wise, T Woller, K Yoneyama, S Zohrabian, H
Citation
A. Airapetian et al., Measurement of longitudinal spin transfer to Lambda hyperons in deep-inelastic lepton scattering - art. no. 112005, PHYS REV D, 6411(11), 2001, pp. 2005
Citations number
37
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
PHYSICAL REVIEW D
ISSN journal
0556-2821 → ACNP
Volume
6411
Issue
11
Year of publication
2001
Database
ISI
SICI code
0556-2821(200112)6411:11<2005:MOLSTT>2.0.ZU;2-6
Abstract
Spin transfer in deep-inelastic Lambda electroproduction has been studied w ith the HERMES detector using the 27.6 GeV polarized positron beam in the D ESY 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 fo und to be 0.11+/-0.17(stat)+/-0.03(syst); similar values are found for othe r possible choices for the longitudinal spin direction of the Lambda. This result is the most precise value obtained to date from deep-inelastic scatt ering with charged lepton beams, and is sensitive to polarized up quark fra gmentation to hyperon states. The experimental result is found to be in gen eral agreement with various models of the Lambda spin content, and is consi stent with the assumption of helicity conservation in the fragmentation pro cess.