Measurement of the Λ polarization in νμ charged current interactions in the NOMAD experiment

P. Astier, D. Autiero, A. Baldisseri, M. Baldo-Ceolin, M. Banner, G. Bassompierre, K. Benslama, N. Besson, I. Bird, B. Blumenfeld, F. Bobisut, J. Bouchez, S. Boyd, A. Bueno, S. Bunyatov, L. Camilleri, A. Cardini, P. W. Cattaneo, V. Cavasinni, A. Cervera-VillanuevaA. Chukanov, G. Collazuol, G. Conforto, C. Conta, M. Contalbrigo, R. Cousins, D. Daniels, H. Degaudenzi, T. del Prete, A. de Santo, T. Dignan, L. di Lella, E. do Couto e Silva, J. Dumarchez, M. Ellis, T. Fazio, G. J. Feldman, R. Ferrari, D. Ferrère, V. Flaminio, M. Fraternali, J. M. Gaillard, E. Gangler, A. Geiser, D. Geppert, D. Gibin, S. Gninenko, A. Godley, J. J. Gomez-Cadenas, J. Gosset, C. Gößling, M. Gouanère, A. Grant, G. Graziani, A. Guglielmi, C. Hagner, J. Hernando, D. Hubbard, P. Hurst, N. Hyett, E. Iacopini, C. Joseph, F. Juget, M. Kirsanov, O. Klimov, J. Kokkonen, A. Kovzelev, A. Krasnoperov, D. Kustov, V. Kuznetsov, S. Lacaprara, C. Lachaud, B. Lakić, A. Lanza, L. la Rotonda, M. Laveder, A. Letessier-Selvon, J. M. Levy, L. Linssen, A. Ljubičić, J. Long, A. Lupi, A. Marchionni, F. Martelli, X. Méchain, J. P. Mendiburu, J. P. Meyer, M. Mezzetto, S. R. Mishra, G. F. Moorhead, D. Naumov, P. Nédélec, Yu Nefedov, C. Nguyen-Mau, D. Orestano, F. Pastore, L. S. Peak, E. Pennacchio, H. Pessard, R. Petti, A. Placci, G. Polesello, D. Pollmann, A. Polyarush, B. Popov, C. Poulsen, P. Rathouit, J. Rico, P. Riemann, C. Roda, A. Rubbia, F. Salvatore, K. Schahmaneche, B. Schmidt, T. Schmidt, M. Sevior, D. Sillou, F. J.P. Soler, G. Sozzi, D. Steele, U. Stiegler, M. Stipčević, Th Stolarczyk, M. Tareb-Reyes, G. N. Taylor, V. Tereshchenko, A. Toropin, A. M. Touchard, S. N. Tovey, M. T. Tran, E. Tsesmelis, J. Ulrichs, L. Vacavant, M. Valdata-Nappi, V. Valuev, F. Vannucci, K. E. Varvell, M. Veltri, V. Vercesi, J. M. Vieira, T. Vinogradova, F. V. Weber, T. Weisse, F. F. Wilson, L. J. Winton, B. D. Yabsley, H. Zaccone, K. Zuber, P. Zuccon

Research output: Contribution to journalArticle

83 Citations (Scopus)

Abstract

The Λ polarization in νμ charged current interactions has been measured in the NOMAD experiment. The event sample (8087 reconstructed Λ 's) is more than an order of magnitude larger than that of previous bubble chamber experiments, while the quality of event reconstruction is comparable. We observe negative polarization along the W -boson direction which is enhanced in the target fragmentation region: Px(xF<0)=-0.21±0.04(stat)±0.02(sys) . In the current fragmentation region we find Px(xF>0)=-0.09±0.06(stat)±0.03(sys) . These results provide a test of different models describing the nucleon spin composition and the spin transfer mechanisms. A significant transverse polarization (in the direction orthogonal to the Λ production plane) has been observed for the first time in a neutrino experiment: Py=-0.22±0.03(stat)±0.01(sys) . The dependence of the absolute value of Py on the Λ transverse momentum with respect to the hadronic jet direction is in qualitative agreement with the results from unpolarized hadron-hadron experiments.

Original languageEnglish (US)
Pages (from-to)3-36
Number of pages34
JournalNuclear Physics B
Volume588
Issue number1-2
DOIs
StatePublished - Nov 6 2000
Externally publishedYes

Fingerprint

polarization
bubble chambers
interactions
transverse momentum
fragmentation
bosons
neutrinos

Keywords

  • Lambda polarization
  • Neutrino interactions
  • Nucleon spin
  • Spin transfer

ASJC Scopus subject areas

  • Nuclear and High Energy Physics

Cite this

Astier, P., Autiero, D., Baldisseri, A., Baldo-Ceolin, M., Banner, M., Bassompierre, G., ... Zuccon, P. (2000). Measurement of the Λ polarization in νμ charged current interactions in the NOMAD experiment. Nuclear Physics B, 588(1-2), 3-36. https://doi.org/10.1016/S0550-3213(00)00503-4

Measurement of the Λ polarization in νμ charged current interactions in the NOMAD experiment. / Astier, P.; Autiero, D.; Baldisseri, A.; Baldo-Ceolin, M.; Banner, M.; Bassompierre, G.; Benslama, K.; Besson, N.; Bird, I.; Blumenfeld, B.; Bobisut, F.; Bouchez, J.; Boyd, S.; Bueno, A.; Bunyatov, S.; Camilleri, L.; Cardini, A.; Cattaneo, P. W.; Cavasinni, V.; Cervera-Villanueva, A.; Chukanov, A.; Collazuol, G.; Conforto, G.; Conta, C.; Contalbrigo, M.; Cousins, R.; Daniels, D.; Degaudenzi, H.; del Prete, T.; de Santo, A.; Dignan, T.; di Lella, L.; do Couto e Silva, E.; Dumarchez, J.; Ellis, M.; Fazio, T.; Feldman, G. J.; Ferrari, R.; Ferrère, D.; Flaminio, V.; Fraternali, M.; Gaillard, J. M.; Gangler, E.; Geiser, A.; Geppert, D.; Gibin, D.; Gninenko, S.; Godley, A.; Gomez-Cadenas, J. J.; Gosset, J.; Gößling, C.; Gouanère, M.; Grant, A.; Graziani, G.; Guglielmi, A.; Hagner, C.; Hernando, J.; Hubbard, D.; Hurst, P.; Hyett, N.; Iacopini, E.; Joseph, C.; Juget, F.; Kirsanov, M.; Klimov, O.; Kokkonen, J.; Kovzelev, A.; Krasnoperov, A.; Kustov, D.; Kuznetsov, V.; Lacaprara, S.; Lachaud, C.; Lakić, B.; Lanza, A.; la Rotonda, L.; Laveder, M.; Letessier-Selvon, A.; Levy, J. M.; Linssen, L.; Ljubičić, A.; Long, J.; Lupi, A.; Marchionni, A.; Martelli, F.; Méchain, X.; Mendiburu, J. P.; Meyer, J. P.; Mezzetto, M.; Mishra, S. R.; Moorhead, G. F.; Naumov, D.; Nédélec, P.; Nefedov, Yu; Nguyen-Mau, C.; Orestano, D.; Pastore, F.; Peak, L. S.; Pennacchio, E.; Pessard, H.; Petti, R.; Placci, A.; Polesello, G.; Pollmann, D.; Polyarush, A.; Popov, B.; Poulsen, C.; Rathouit, P.; Rico, J.; Riemann, P.; Roda, C.; Rubbia, A.; Salvatore, F.; Schahmaneche, K.; Schmidt, B.; Schmidt, T.; Sevior, M.; Sillou, D.; Soler, F. J.P.; Sozzi, G.; Steele, D.; Stiegler, U.; Stipčević, M.; Stolarczyk, Th; Tareb-Reyes, M.; Taylor, G. N.; Tereshchenko, V.; Toropin, A.; Touchard, A. M.; Tovey, S. N.; Tran, M. T.; Tsesmelis, E.; Ulrichs, J.; Vacavant, L.; Valdata-Nappi, M.; Valuev, V.; Vannucci, F.; Varvell, K. E.; Veltri, M.; Vercesi, V.; Vieira, J. M.; Vinogradova, T.; Weber, F. V.; Weisse, T.; Wilson, F. F.; Winton, L. J.; Yabsley, B. D.; Zaccone, H.; Zuber, K.; Zuccon, P.

In: Nuclear Physics B, Vol. 588, No. 1-2, 06.11.2000, p. 3-36.

Research output: Contribution to journalArticle

Astier, P, Autiero, D, Baldisseri, A, Baldo-Ceolin, M, Banner, M, Bassompierre, G, Benslama, K, Besson, N, Bird, I, Blumenfeld, B, Bobisut, F, Bouchez, J, Boyd, S, Bueno, A, Bunyatov, S, Camilleri, L, Cardini, A, Cattaneo, PW, Cavasinni, V, Cervera-Villanueva, A, Chukanov, A, Collazuol, G, Conforto, G, Conta, C, Contalbrigo, M, Cousins, R, Daniels, D, Degaudenzi, H, del Prete, T, de Santo, A, Dignan, T, di Lella, L, do Couto e Silva, E, Dumarchez, J, Ellis, M, Fazio, T, Feldman, GJ, Ferrari, R, Ferrère, D, Flaminio, V, Fraternali, M, Gaillard, JM, Gangler, E, Geiser, A, Geppert, D, Gibin, D, Gninenko, S, Godley, A, Gomez-Cadenas, JJ, Gosset, J, Gößling, C, Gouanère, M, Grant, A, Graziani, G, Guglielmi, A, Hagner, C, Hernando, J, Hubbard, D, Hurst, P, Hyett, N, Iacopini, E, Joseph, C, Juget, F, Kirsanov, M, Klimov, O, Kokkonen, J, Kovzelev, A, Krasnoperov, A, Kustov, D, Kuznetsov, V, Lacaprara, S, Lachaud, C, Lakić, B, Lanza, A, la Rotonda, L, Laveder, M, Letessier-Selvon, A, Levy, JM, Linssen, L, Ljubičić, A, Long, J, Lupi, A, Marchionni, A, Martelli, F, Méchain, X, Mendiburu, JP, Meyer, JP, Mezzetto, M, Mishra, SR, Moorhead, GF, Naumov, D, Nédélec, P, Nefedov, Y, Nguyen-Mau, C, Orestano, D, Pastore, F, Peak, LS, Pennacchio, E, Pessard, H, Petti, R, Placci, A, Polesello, G, Pollmann, D, Polyarush, A, Popov, B, Poulsen, C, Rathouit, P, Rico, J, Riemann, P, Roda, C, Rubbia, A, Salvatore, F, Schahmaneche, K, Schmidt, B, Schmidt, T, Sevior, M, Sillou, D, Soler, FJP, Sozzi, G, Steele, D, Stiegler, U, Stipčević, M, Stolarczyk, T, Tareb-Reyes, M, Taylor, GN, Tereshchenko, V, Toropin, A, Touchard, AM, Tovey, SN, Tran, MT, Tsesmelis, E, Ulrichs, J, Vacavant, L, Valdata-Nappi, M, Valuev, V, Vannucci, F, Varvell, KE, Veltri, M, Vercesi, V, Vieira, JM, Vinogradova, T, Weber, FV, Weisse, T, Wilson, FF, Winton, LJ, Yabsley, BD, Zaccone, H, Zuber, K & Zuccon, P 2000, 'Measurement of the Λ polarization in νμ charged current interactions in the NOMAD experiment', Nuclear Physics B, vol. 588, no. 1-2, pp. 3-36. https://doi.org/10.1016/S0550-3213(00)00503-4
Astier P, Autiero D, Baldisseri A, Baldo-Ceolin M, Banner M, Bassompierre G et al. Measurement of the Λ polarization in νμ charged current interactions in the NOMAD experiment. Nuclear Physics B. 2000 Nov 6;588(1-2):3-36. https://doi.org/10.1016/S0550-3213(00)00503-4
Astier, P. ; Autiero, D. ; Baldisseri, A. ; Baldo-Ceolin, M. ; Banner, M. ; Bassompierre, G. ; Benslama, K. ; Besson, N. ; Bird, I. ; Blumenfeld, B. ; Bobisut, F. ; Bouchez, J. ; Boyd, S. ; Bueno, A. ; Bunyatov, S. ; Camilleri, L. ; Cardini, A. ; Cattaneo, P. W. ; Cavasinni, V. ; Cervera-Villanueva, A. ; Chukanov, A. ; Collazuol, G. ; Conforto, G. ; Conta, C. ; Contalbrigo, M. ; Cousins, R. ; Daniels, D. ; Degaudenzi, H. ; del Prete, T. ; de Santo, A. ; Dignan, T. ; di Lella, L. ; do Couto e Silva, E. ; Dumarchez, J. ; Ellis, M. ; Fazio, T. ; Feldman, G. J. ; Ferrari, R. ; Ferrère, D. ; Flaminio, V. ; Fraternali, M. ; Gaillard, J. M. ; Gangler, E. ; Geiser, A. ; Geppert, D. ; Gibin, D. ; Gninenko, S. ; Godley, A. ; Gomez-Cadenas, J. J. ; Gosset, J. ; Gößling, C. ; Gouanère, M. ; Grant, A. ; Graziani, G. ; Guglielmi, A. ; Hagner, C. ; Hernando, J. ; Hubbard, D. ; Hurst, P. ; Hyett, N. ; Iacopini, E. ; Joseph, C. ; Juget, F. ; Kirsanov, M. ; Klimov, O. ; Kokkonen, J. ; Kovzelev, A. ; Krasnoperov, A. ; Kustov, D. ; Kuznetsov, V. ; Lacaprara, S. ; Lachaud, C. ; Lakić, B. ; Lanza, A. ; la Rotonda, L. ; Laveder, M. ; Letessier-Selvon, A. ; Levy, J. M. ; Linssen, L. ; Ljubičić, A. ; Long, J. ; Lupi, A. ; Marchionni, A. ; Martelli, F. ; Méchain, X. ; Mendiburu, J. P. ; Meyer, J. P. ; Mezzetto, M. ; Mishra, S. R. ; Moorhead, G. F. ; Naumov, D. ; Nédélec, P. ; Nefedov, Yu ; Nguyen-Mau, C. ; Orestano, D. ; Pastore, F. ; Peak, L. S. ; Pennacchio, E. ; Pessard, H. ; Petti, R. ; Placci, A. ; Polesello, G. ; Pollmann, D. ; Polyarush, A. ; Popov, B. ; Poulsen, C. ; Rathouit, P. ; Rico, J. ; Riemann, P. ; Roda, C. ; Rubbia, A. ; Salvatore, F. ; Schahmaneche, K. ; Schmidt, B. ; Schmidt, T. ; Sevior, M. ; Sillou, D. ; Soler, F. J.P. ; Sozzi, G. ; Steele, D. ; Stiegler, U. ; Stipčević, M. ; Stolarczyk, Th ; Tareb-Reyes, M. ; Taylor, G. N. ; Tereshchenko, V. ; Toropin, A. ; Touchard, A. M. ; Tovey, S. N. ; Tran, M. T. ; Tsesmelis, E. ; Ulrichs, J. ; Vacavant, L. ; Valdata-Nappi, M. ; Valuev, V. ; Vannucci, F. ; Varvell, K. E. ; Veltri, M. ; Vercesi, V. ; Vieira, J. M. ; Vinogradova, T. ; Weber, F. V. ; Weisse, T. ; Wilson, F. F. ; Winton, L. J. ; Yabsley, B. D. ; Zaccone, H. ; Zuber, K. ; Zuccon, P. / Measurement of the Λ polarization in νμ charged current interactions in the NOMAD experiment. In: Nuclear Physics B. 2000 ; Vol. 588, No. 1-2. pp. 3-36.
@article{208f7d4d9c084de7baeddb64668438f1,
title = "Measurement of the Λ polarization in νμ charged current interactions in the NOMAD experiment",
abstract = "The Λ polarization in νμ charged current interactions has been measured in the NOMAD experiment. The event sample (8087 reconstructed Λ 's) is more than an order of magnitude larger than that of previous bubble chamber experiments, while the quality of event reconstruction is comparable. We observe negative polarization along the W -boson direction which is enhanced in the target fragmentation region: Px(xF<0)=-0.21±0.04(stat)±0.02(sys) . In the current fragmentation region we find Px(xF>0)=-0.09±0.06(stat)±0.03(sys) . These results provide a test of different models describing the nucleon spin composition and the spin transfer mechanisms. A significant transverse polarization (in the direction orthogonal to the Λ production plane) has been observed for the first time in a neutrino experiment: Py=-0.22±0.03(stat)±0.01(sys) . The dependence of the absolute value of Py on the Λ transverse momentum with respect to the hadronic jet direction is in qualitative agreement with the results from unpolarized hadron-hadron experiments.",
keywords = "Lambda polarization, Neutrino interactions, Nucleon spin, Spin transfer",
author = "P. Astier and D. Autiero and A. Baldisseri and M. Baldo-Ceolin and M. Banner and G. Bassompierre and K. Benslama and N. Besson and I. Bird and B. Blumenfeld and F. Bobisut and J. Bouchez and S. Boyd and A. Bueno and S. Bunyatov and L. Camilleri and A. Cardini and Cattaneo, {P. W.} and V. Cavasinni and A. Cervera-Villanueva and A. Chukanov and G. Collazuol and G. Conforto and C. Conta and M. Contalbrigo and R. Cousins and D. Daniels and H. Degaudenzi and {del Prete}, T. and {de Santo}, A. and T. Dignan and {di Lella}, L. and {do Couto e Silva}, E. and J. Dumarchez and M. Ellis and T. Fazio and Feldman, {G. J.} and R. Ferrari and D. Ferr{\`e}re and V. Flaminio and M. Fraternali and Gaillard, {J. M.} and E. Gangler and A. Geiser and D. Geppert and D. Gibin and S. Gninenko and A. Godley and Gomez-Cadenas, {J. J.} and J. Gosset and C. G{\"o}{\ss}ling and M. Gouan{\`e}re and A. Grant and G. Graziani and A. Guglielmi and C. Hagner and J. Hernando and D. Hubbard and P. Hurst and N. Hyett and E. Iacopini and C. Joseph and F. Juget and M. Kirsanov and O. Klimov and J. Kokkonen and A. Kovzelev and A. Krasnoperov and D. Kustov and V. Kuznetsov and S. Lacaprara and C. Lachaud and B. Lakić and A. Lanza and {la Rotonda}, L. and M. Laveder and A. Letessier-Selvon and Levy, {J. M.} and L. Linssen and A. Ljubičić and J. Long and A. Lupi and A. Marchionni and F. Martelli and X. M{\'e}chain and Mendiburu, {J. P.} and Meyer, {J. P.} and M. Mezzetto and Mishra, {S. R.} and Moorhead, {G. F.} and D. Naumov and P. N{\'e}d{\'e}lec and Yu Nefedov and C. Nguyen-Mau and D. Orestano and F. Pastore and Peak, {L. S.} and E. Pennacchio and H. Pessard and R. Petti and A. Placci and G. Polesello and D. Pollmann and A. Polyarush and B. Popov and C. Poulsen and P. Rathouit and J. Rico and P. Riemann and C. Roda and A. Rubbia and F. Salvatore and K. Schahmaneche and B. Schmidt and T. Schmidt and M. Sevior and D. Sillou and Soler, {F. J.P.} and G. Sozzi and D. Steele and U. Stiegler and M. Stipčević and Th Stolarczyk and M. Tareb-Reyes and Taylor, {G. N.} and V. Tereshchenko and A. Toropin and Touchard, {A. M.} and Tovey, {S. N.} and Tran, {M. T.} and E. Tsesmelis and J. Ulrichs and L. Vacavant and M. Valdata-Nappi and V. Valuev and F. Vannucci and Varvell, {K. E.} and M. Veltri and V. Vercesi and Vieira, {J. M.} and T. Vinogradova and Weber, {F. V.} and T. Weisse and Wilson, {F. F.} and Winton, {L. J.} and Yabsley, {B. D.} and H. Zaccone and K. Zuber and P. Zuccon",
year = "2000",
month = "11",
day = "6",
doi = "10.1016/S0550-3213(00)00503-4",
language = "English (US)",
volume = "588",
pages = "3--36",
journal = "Nuclear Physics B",
issn = "0550-3213",
publisher = "Elsevier",
number = "1-2",

}

TY - JOUR

T1 - Measurement of the Λ polarization in νμ charged current interactions in the NOMAD experiment

AU - Astier, P.

AU - Autiero, D.

AU - Baldisseri, A.

AU - Baldo-Ceolin, M.

AU - Banner, M.

AU - Bassompierre, G.

AU - Benslama, K.

AU - Besson, N.

AU - Bird, I.

AU - Blumenfeld, B.

AU - Bobisut, F.

AU - Bouchez, J.

AU - Boyd, S.

AU - Bueno, A.

AU - Bunyatov, S.

AU - Camilleri, L.

AU - Cardini, A.

AU - Cattaneo, P. W.

AU - Cavasinni, V.

AU - Cervera-Villanueva, A.

AU - Chukanov, A.

AU - Collazuol, G.

AU - Conforto, G.

AU - Conta, C.

AU - Contalbrigo, M.

AU - Cousins, R.

AU - Daniels, D.

AU - Degaudenzi, H.

AU - del Prete, T.

AU - de Santo, A.

AU - Dignan, T.

AU - di Lella, L.

AU - do Couto e Silva, E.

AU - Dumarchez, J.

AU - Ellis, M.

AU - Fazio, T.

AU - Feldman, G. J.

AU - Ferrari, R.

AU - Ferrère, D.

AU - Flaminio, V.

AU - Fraternali, M.

AU - Gaillard, J. M.

AU - Gangler, E.

AU - Geiser, A.

AU - Geppert, D.

AU - Gibin, D.

AU - Gninenko, S.

AU - Godley, A.

AU - Gomez-Cadenas, J. J.

AU - Gosset, J.

AU - Gößling, C.

AU - Gouanère, M.

AU - Grant, A.

AU - Graziani, G.

AU - Guglielmi, A.

AU - Hagner, C.

AU - Hernando, J.

AU - Hubbard, D.

AU - Hurst, P.

AU - Hyett, N.

AU - Iacopini, E.

AU - Joseph, C.

AU - Juget, F.

AU - Kirsanov, M.

AU - Klimov, O.

AU - Kokkonen, J.

AU - Kovzelev, A.

AU - Krasnoperov, A.

AU - Kustov, D.

AU - Kuznetsov, V.

AU - Lacaprara, S.

AU - Lachaud, C.

AU - Lakić, B.

AU - Lanza, A.

AU - la Rotonda, L.

AU - Laveder, M.

AU - Letessier-Selvon, A.

AU - Levy, J. M.

AU - Linssen, L.

AU - Ljubičić, A.

AU - Long, J.

AU - Lupi, A.

AU - Marchionni, A.

AU - Martelli, F.

AU - Méchain, X.

AU - Mendiburu, J. P.

AU - Meyer, J. P.

AU - Mezzetto, M.

AU - Mishra, S. R.

AU - Moorhead, G. F.

AU - Naumov, D.

AU - Nédélec, P.

AU - Nefedov, Yu

AU - Nguyen-Mau, C.

AU - Orestano, D.

AU - Pastore, F.

AU - Peak, L. S.

AU - Pennacchio, E.

AU - Pessard, H.

AU - Petti, R.

AU - Placci, A.

AU - Polesello, G.

AU - Pollmann, D.

AU - Polyarush, A.

AU - Popov, B.

AU - Poulsen, C.

AU - Rathouit, P.

AU - Rico, J.

AU - Riemann, P.

AU - Roda, C.

AU - Rubbia, A.

AU - Salvatore, F.

AU - Schahmaneche, K.

AU - Schmidt, B.

AU - Schmidt, T.

AU - Sevior, M.

AU - Sillou, D.

AU - Soler, F. J.P.

AU - Sozzi, G.

AU - Steele, D.

AU - Stiegler, U.

AU - Stipčević, M.

AU - Stolarczyk, Th

AU - Tareb-Reyes, M.

AU - Taylor, G. N.

AU - Tereshchenko, V.

AU - Toropin, A.

AU - Touchard, A. M.

AU - Tovey, S. N.

AU - Tran, M. T.

AU - Tsesmelis, E.

AU - Ulrichs, J.

AU - Vacavant, L.

AU - Valdata-Nappi, M.

AU - Valuev, V.

AU - Vannucci, F.

AU - Varvell, K. E.

AU - Veltri, M.

AU - Vercesi, V.

AU - Vieira, J. M.

AU - Vinogradova, T.

AU - Weber, F. V.

AU - Weisse, T.

AU - Wilson, F. F.

AU - Winton, L. J.

AU - Yabsley, B. D.

AU - Zaccone, H.

AU - Zuber, K.

AU - Zuccon, P.

PY - 2000/11/6

Y1 - 2000/11/6

N2 - The Λ polarization in νμ charged current interactions has been measured in the NOMAD experiment. The event sample (8087 reconstructed Λ 's) is more than an order of magnitude larger than that of previous bubble chamber experiments, while the quality of event reconstruction is comparable. We observe negative polarization along the W -boson direction which is enhanced in the target fragmentation region: Px(xF<0)=-0.21±0.04(stat)±0.02(sys) . In the current fragmentation region we find Px(xF>0)=-0.09±0.06(stat)±0.03(sys) . These results provide a test of different models describing the nucleon spin composition and the spin transfer mechanisms. A significant transverse polarization (in the direction orthogonal to the Λ production plane) has been observed for the first time in a neutrino experiment: Py=-0.22±0.03(stat)±0.01(sys) . The dependence of the absolute value of Py on the Λ transverse momentum with respect to the hadronic jet direction is in qualitative agreement with the results from unpolarized hadron-hadron experiments.

AB - The Λ polarization in νμ charged current interactions has been measured in the NOMAD experiment. The event sample (8087 reconstructed Λ 's) is more than an order of magnitude larger than that of previous bubble chamber experiments, while the quality of event reconstruction is comparable. We observe negative polarization along the W -boson direction which is enhanced in the target fragmentation region: Px(xF<0)=-0.21±0.04(stat)±0.02(sys) . In the current fragmentation region we find Px(xF>0)=-0.09±0.06(stat)±0.03(sys) . These results provide a test of different models describing the nucleon spin composition and the spin transfer mechanisms. A significant transverse polarization (in the direction orthogonal to the Λ production plane) has been observed for the first time in a neutrino experiment: Py=-0.22±0.03(stat)±0.01(sys) . The dependence of the absolute value of Py on the Λ transverse momentum with respect to the hadronic jet direction is in qualitative agreement with the results from unpolarized hadron-hadron experiments.

KW - Lambda polarization

KW - Neutrino interactions

KW - Nucleon spin

KW - Spin transfer

UR - http://www.scopus.com/inward/record.url?scp=17544397420&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=17544397420&partnerID=8YFLogxK

U2 - 10.1016/S0550-3213(00)00503-4

DO - 10.1016/S0550-3213(00)00503-4

M3 - Article

AN - SCOPUS:17544397420

VL - 588

SP - 3

EP - 36

JO - Nuclear Physics B

JF - Nuclear Physics B

SN - 0550-3213

IS - 1-2

ER -