Single-spin asymmetries for pions and charged kaons are measured in semi-inclusive deep-inelastic scattering of positrons and electrons off a transversely nuclear-polarized hydrogen target. The dependence of the cross section on the azimuthal angles of the target polarization (phi s) and the produced hadron (phi) is found to have a substantial sin(phi +phi s) modulation for the production of pi(+), pi(-) and K(+). This Fourier component can be interpreted in terms of non-zero transversity distribution functions and non-zero favored and disfavored Collins fragmentation functions with opposite sign. For pi(0) and K(-) production the amplitude of this Fourier component is consistent with zero.

Effects of transversity in deep-inelastic scattering by polarized protons

BACCHETTA, ALESSANDRO;
2010-01-01

Abstract

Single-spin asymmetries for pions and charged kaons are measured in semi-inclusive deep-inelastic scattering of positrons and electrons off a transversely nuclear-polarized hydrogen target. The dependence of the cross section on the azimuthal angles of the target polarization (phi s) and the produced hadron (phi) is found to have a substantial sin(phi +phi s) modulation for the production of pi(+), pi(-) and K(+). This Fourier component can be interpreted in terms of non-zero transversity distribution functions and non-zero favored and disfavored Collins fragmentation functions with opposite sign. For pi(0) and K(-) production the amplitude of this Fourier component is consistent with zero.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11571/214023
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