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

HERMES Collaboration

doi:10.1103/PhysRevD.64.112005

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

HERMES Collaboration

Research output: Contribution to journal › Article › Academic › peer-review

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 language	English
Article number	112005
Number of pages	7
Journal	Physical Review D
Volume	64
Issue number	11
DOIs	https://doi.org/10.1103/PhysRevD.64.112005
Publication status	Published - 1 Dec 2001
Externally published	Yes

Keywords

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

Access to Document

10.1103/PhysRevD.64.112005

Cite this

@article{db07990f29b04f1897f0ccfafaae1a06,

title = "Measurement of longitudinal spin transfer to Lambda hyperons in deep-inelastic lepton scattering",

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.",

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

author = "A. Airapetian and N. Akopov and M. Amarian and E.C. Aschenauer and H. Avakian and R. Avakian and A. Avetissian and B. Bains and C. Baumgarten and M. Beckmann and S. Belostotski and J.E. Belz and T. Benisch and S. Bernreuther and N. Bianchi and J. Blouw and H. Bottcher and A. Borissov and M. Bouwhuis and J. Brack and S. Brauksiepe and B. Braun and B. Bray and S. Brons and W. Bruckner and A. Brull and E.E.W. Bruins and H.J. Bulten and G.P. Capitani and P. Carter and P. Chumney and E. Cisbani and G.R. Court and P.F. Dalpiaz and {De Sanctis}, E. and {De Schepper}, D. and E. Devitsin and P.K.A.D. Huberts and {Di Nezza}, P. and M. Duren and A. Dvoredsky and G. Elbakian and J. Ely and A. Fantoni and A. Fechtchenko and M. Ferstl and K. Fiedler and B.W. Filippone and H. Fischer and {van den Brand}, J.F.J. and {HERMES Collaboration}",

year = "2001",

month = dec,

day = "1",

doi = "10.1103/PhysRevD.64.112005",

language = "English",

volume = "64",

journal = "Physical Review D",

issn = "1550-7998",

publisher = "American Physical Society",

number = "11",

}

TY - JOUR

T1 - Measurement of longitudinal spin transfer to Lambda hyperons in deep-inelastic lepton scattering

AU - Airapetian, A.

AU - Akopov, N.

AU - Amarian, M.

AU - Aschenauer, E.C.

AU - Avakian, H.

AU - Avakian, R.

AU - Avetissian, A.

AU - Bains, B.

AU - Baumgarten, C.

AU - Beckmann, M.

AU - Belostotski, S.

AU - Belz, J.E.

AU - Benisch, T.

AU - Bernreuther, S.

AU - Bianchi, N.

AU - Blouw, J.

AU - Bottcher, H.

AU - Borissov, A.

AU - Bouwhuis, M.

AU - Brack, J.

AU - Brauksiepe, S.

AU - Braun, B.

AU - Bray, B.

AU - Brons, S.

AU - Bruckner, W.

AU - Brull, A.

AU - Bruins, E.E.W.

AU - Bulten, H.J.

AU - Capitani, G.P.

AU - Carter, P.

AU - Chumney, P.

AU - Cisbani, E.

AU - Court, G.R.

AU - Dalpiaz, P.F.

AU - De Sanctis, E.

AU - De Schepper, D.

AU - Devitsin, E.

AU - Huberts, P.K.A.D.

AU - Di Nezza, P.

AU - Duren, M.

AU - Dvoredsky, A.

AU - Elbakian, G.

AU - Ely, J.

AU - Fantoni, A.

AU - Fechtchenko, A.

AU - Ferstl, M.

AU - Fiedler, K.

AU - Filippone, B.W.

AU - Fischer, H.

AU - van den Brand, J.F.J.

AU - HERMES Collaboration

PY - 2001/12/1

Y1 - 2001/12/1

N2 - 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.

AB - 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.

KW - POLARIZED QUARK DISTRIBUTIONS

KW - STRUCTURE-FUNCTION G(1)(P)

KW - MUON SCATTERING

KW - (LAMBDA)OVER-BAR POLARIZATION

KW - Z-DECAYS

KW - PROTON

KW - DEUTERON

KW - ASYMMETRIES

KW - NUCLEON

KW - BARYONS

U2 - 10.1103/PhysRevD.64.112005

DO - 10.1103/PhysRevD.64.112005

M3 - Article

SN - 1550-7998

VL - 64

JO - Physical Review D

JF - Physical Review D

IS - 11

M1 - 112005

ER -