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Title: Evidence for a single-spin azimuthal asymmetry in semi-inclusive pion electro-production.

Abstract

Single-spin asymmetries for semi-inclusive pion production in deep-inelastic scattering have been measured for the first time. A significant target-spin asymmetry of the distribution in the azimuthal angle {var_phi} of the pion relative to the lepton scattering plane was formed for {pi}{sup +} electroproduction on a longitudinally polarized hydrogen target. The corresponding analyzing power in the sin{var_phi} moment of the cross section is 0.022{+-}0.005{+-}0.003. This result can be interpreted as the effect of terms in the cross section involving chiral-odd spin distribution functions in combination with a chiral-odd fragmentation function that is sensitive to the transverse polarization of the fragmenting quark.

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
943124
Report Number(s):
ANL/PHY/JA-37670
Journal ID: ISSN 0031-9007; PRLTAO; TRN: US201002%%611
DOE Contract Number:  
DE-AC02-06CH11357
Resource Type:
Journal Article
Journal Name:
Phys. Rev. Lett.
Additional Journal Information:
Journal Volume: 84; Journal Issue: 18 ; May 2000; Journal ID: ISSN 0031-9007
Country of Publication:
United States
Language:
ENGLISH
Subject:
08 HYDROGEN; ASYMMETRY; CROSS SECTIONS; DISTRIBUTION FUNCTIONS; ELECTROPRODUCTION; FRAGMENTATION; HYDROGEN; LEPTONS; PIONS; POLARIZED TARGETS; POLARIZATION; POLARIZATION-ASYMMETRY RATIO; PRODUCTION; DEEP INELASTIC SCATTERING; SCATTERING; SPIN

Citation Formats

Airapetian, A., Akopov, N., Amarian, M., Aschenauer, E. C., Avakian, H., De Schepper, D., Gao, H., Hansen, J.-O., Jackson, H. E., Makins, N. C. R., O'Neill, T. G., Potterveld, D. H., HERMES Collaboration, Physics, Yerevan Physics Inst., National Inst. voor Kernfysica en Hoge-Energiefysica, Inst. Superiore di Sanita, Massachusetts Inst. of Tech., and Univ. of Illinois. Evidence for a single-spin azimuthal asymmetry in semi-inclusive pion electro-production.. United States: N. p., 2000. Web. doi:10.1103/PhysRevLett.84.4047.
Airapetian, A., Akopov, N., Amarian, M., Aschenauer, E. C., Avakian, H., De Schepper, D., Gao, H., Hansen, J.-O., Jackson, H. E., Makins, N. C. R., O'Neill, T. G., Potterveld, D. H., HERMES Collaboration, Physics, Yerevan Physics Inst., National Inst. voor Kernfysica en Hoge-Energiefysica, Inst. Superiore di Sanita, Massachusetts Inst. of Tech., & Univ. of Illinois. Evidence for a single-spin azimuthal asymmetry in semi-inclusive pion electro-production.. United States. doi:10.1103/PhysRevLett.84.4047.
Airapetian, A., Akopov, N., Amarian, M., Aschenauer, E. C., Avakian, H., De Schepper, D., Gao, H., Hansen, J.-O., Jackson, H. E., Makins, N. C. R., O'Neill, T. G., Potterveld, D. H., HERMES Collaboration, Physics, Yerevan Physics Inst., National Inst. voor Kernfysica en Hoge-Energiefysica, Inst. Superiore di Sanita, Massachusetts Inst. of Tech., and Univ. of Illinois. Mon . "Evidence for a single-spin azimuthal asymmetry in semi-inclusive pion electro-production.". United States. doi:10.1103/PhysRevLett.84.4047.
@article{osti_943124,
title = {Evidence for a single-spin azimuthal asymmetry in semi-inclusive pion electro-production.},
author = {Airapetian, A. and Akopov, N. and Amarian, M. and Aschenauer, E. C. and Avakian, H. and De Schepper, D. and Gao, H. and Hansen, J.-O. and Jackson, H. E. and Makins, N. C. R. and O'Neill, T. G. and Potterveld, D. H. and HERMES Collaboration and Physics and Yerevan Physics Inst. and National Inst. voor Kernfysica en Hoge-Energiefysica and Inst. Superiore di Sanita and Massachusetts Inst. of Tech. and Univ. of Illinois},
abstractNote = {Single-spin asymmetries for semi-inclusive pion production in deep-inelastic scattering have been measured for the first time. A significant target-spin asymmetry of the distribution in the azimuthal angle {var_phi} of the pion relative to the lepton scattering plane was formed for {pi}{sup +} electroproduction on a longitudinally polarized hydrogen target. The corresponding analyzing power in the sin{var_phi} moment of the cross section is 0.022{+-}0.005{+-}0.003. This result can be interpreted as the effect of terms in the cross section involving chiral-odd spin distribution functions in combination with a chiral-odd fragmentation function that is sensitive to the transverse polarization of the fragmenting quark.},
doi = {10.1103/PhysRevLett.84.4047},
journal = {Phys. Rev. Lett.},
issn = {0031-9007},
number = 18 ; May 2000,
volume = 84,
place = {United States},
year = {2000},
month = {5}
}