







Item type: | Article | ||||
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Journal or Publication Title: | Physical Review Letters | ||||
Publisher: | AMER PHYSICAL SOC | ||||
Place of Publication: | COLLEGE PK | ||||
Volume: | 94 | ||||
Number of Issue or Book Chapter: | 1 | ||||
Date: | 2005 | ||||
Institutions: | Physics > Institute of Theroretical Physics > Chair Professor Schäfer > Group Andreas Schäfer | ||||
Identification Number: |
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Keywords: | FINAL-STATE INTERACTIONS; PARTON DISTRIBUTIONS; DEUTERIUM TARGET; AZIMUTHAL ASYMMETRIES; DRELL-YAN; HERMES; FRAGMENTATION; ELECTROPRODUCTION; CONSTITUENTS; QUARKS; | ||||
Dewey Decimal Classification: | 500 Science > 530 Physics | ||||
Status: | Published | ||||
Refereed: | Yes, this version has been refereed | ||||
Created at the University of Regensburg: | Yes | ||||
Item ID: | 70973 |
Abstract
Single-spin asymmetries for semi-inclusive electroproduction of charged pions in deep-inelastic scattering of positrons are measured for the first time with transverse target polarization. The asymmetry depends on the azimuthal angles of both the pion (phi) and the target spin axis (phi(S)) about the virtual-photon direction and relative to the lepton scattering plane. The extracted Fourier ...

Abstract
Single-spin asymmetries for semi-inclusive electroproduction of charged pions in deep-inelastic scattering of positrons are measured for the first time with transverse target polarization. The asymmetry depends on the azimuthal angles of both the pion (phi) and the target spin axis (phi(S)) about the virtual-photon direction and relative to the lepton scattering plane. The extracted Fourier component <sin(phi+phi(S))>(pi)(UT) is a signal of the previously unmeasured quark transversity distribution, in conjunction with the Collins fragmentation function, also unknown. The component <sin(phi-phi(S)>(pi)(UT) arises from a correlation between the transverse polarization of the target nucleon and the intrinsic transverse momentum of quarks, as represented by the previously unmeasured Sivers distribution function. Evidence for both signals is observed, but the Sivers asymmetry may be affected by exclusive vector meson production.
Metadata last modified: 19 Dec 2024 15:05