skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Transversity and Collins functions from SIDIS and e{sup +}e{sup -} data

Abstract

A global analysis of the experimental data on azimuthal asymmetries in semi-inclusive deep inelastic scattering (SIDIS), from the HERMES and COMPASS Collaborations, and in e{sup +}e{sup -}{yields}h{sub 1}h{sub 2}X processes, from the Belle Collaboration, is performed. It results in the extraction of the Collins fragmentation function and, for the first time, of the transversity distribution function for u and d quarks. These turn out to have opposite signs and to be sizably smaller than their positivity bounds. Predictions for the azimuthal asymmetry A{sub UT}{sup sin({phi}{sub S}+{phi}{sub h})}, as will soon be measured at JLab and COMPASS operating on a transversely polarized proton target, are then presented.

Authors:
; ; ;  [1]; ;  [2];  [3];  [4]
  1. Dipartimento di Fisica Teorica, Universita di Torino and INFN, Sezione di Torino, Via P. Giuria 1, I-10125 Turin (Italy)
  2. Dipartimento di Fisica, Universita di Cagliari and INFN, Sezione di Cagliari, C.P. 170, I-09042 Monserrato (Italy)
  3. Yerevan Physics Institute, 375036 Yerevan (Armenia)
  4. (Russian Federation) and INFN, Sezione di Torino, Via P. Giuria 1, I-10125 Turin (Italy)
Publication Date:
OSTI Identifier:
21020079
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 75; Journal Issue: 5; Other Information: DOI: 10.1103/PhysRevD.75.054032; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ASYMMETRY; CEBAF ACCELERATOR; D QUARKS; DEEP INELASTIC SCATTERING; DISTRIBUTION FUNCTIONS; ELECTRON-POSITRON INTERACTIONS; ELECTRONS; MULTIPARTICLE SPECTROMETERS; PARTICLE IDENTIFICATION; POLARIZED TARGETS; POSITRONS; PROTONS; SEMI-INCLUSIVE INTERACTIONS; U QUARKS

Citation Formats

Anselmino, M., Boglione, M., Prokudin, A., Tuerk, C., D'Alesio, U., Murgia, F., Kotzinian, A., and JINR, 141980 Dubna. Transversity and Collins functions from SIDIS and e{sup +}e{sup -} data. United States: N. p., 2007. Web. doi:10.1103/PHYSREVD.75.054032.
Anselmino, M., Boglione, M., Prokudin, A., Tuerk, C., D'Alesio, U., Murgia, F., Kotzinian, A., & JINR, 141980 Dubna. Transversity and Collins functions from SIDIS and e{sup +}e{sup -} data. United States. doi:10.1103/PHYSREVD.75.054032.
Anselmino, M., Boglione, M., Prokudin, A., Tuerk, C., D'Alesio, U., Murgia, F., Kotzinian, A., and JINR, 141980 Dubna. Thu . "Transversity and Collins functions from SIDIS and e{sup +}e{sup -} data". United States. doi:10.1103/PHYSREVD.75.054032.
@article{osti_21020079,
title = {Transversity and Collins functions from SIDIS and e{sup +}e{sup -} data},
author = {Anselmino, M. and Boglione, M. and Prokudin, A. and Tuerk, C. and D'Alesio, U. and Murgia, F. and Kotzinian, A. and JINR, 141980 Dubna},
abstractNote = {A global analysis of the experimental data on azimuthal asymmetries in semi-inclusive deep inelastic scattering (SIDIS), from the HERMES and COMPASS Collaborations, and in e{sup +}e{sup -}{yields}h{sub 1}h{sub 2}X processes, from the Belle Collaboration, is performed. It results in the extraction of the Collins fragmentation function and, for the first time, of the transversity distribution function for u and d quarks. These turn out to have opposite signs and to be sizably smaller than their positivity bounds. Predictions for the azimuthal asymmetry A{sub UT}{sup sin({phi}{sub S}+{phi}{sub h})}, as will soon be measured at JLab and COMPASS operating on a transversely polarized proton target, are then presented.},
doi = {10.1103/PHYSREVD.75.054032},
journal = {Physical Review. D, Particles Fields},
number = 5,
volume = 75,
place = {United States},
year = {Thu Mar 01 00:00:00 EST 2007},
month = {Thu Mar 01 00:00:00 EST 2007}
}
  • We present a global re-analysis of the most recent experimental data on azimuthal asymmetries in semi-inclusive deep inelastic scattering, from the HERMES and COMPASS Collaborations, and in e{sup +}e{sup -} {yields} h{sub 1} h{sub 2} X processes, from the Belle Collaboration. The transversity and the Collins functions are extracted simultaneously, in the framework of a revised global analysis in which a new parameterisation of the unknown functions is also tested.
  • The recent data on the transverse single spin asymmetry A{sub UT}{sup sin({phi}{sub h}+{phi}{sub S})} from HERMES and COMPASS Collaborations are analysed within LO parton model with unintegrated parton distribution and fragmentation functions. A fit of SIDIS data from HERMES Collaboration is performed leading to the extraction of favoured and unfavoured Collins fragmentation functions. A very good description of COMPASS data is obtained. BELLE e+e- data are shown to be compatible with our estimates based on the extracted Collins fragmentation functions. Predictions for A{sub UT}{sup sin({phi}{sub h}+{phi}{sub S})} asymmetries at JLab and COMPASS operating on a proton target are given.
  • We review the present understanding of the nucleon transversity distribution and Collins fragmentation function, based on Ref.[1], and discuss how Drell-Yan experiments will improve it.
  • We present an update of a previous global analysis of the experimental data on azimuthal asymmetries in semi-inclusive deep inelastic scattering (SIDIS), from the HERMES and COMPASS Collaborations, and in e{sup +}e{sup -}{yields}h{sub 1}h{sub 2}X processes, from the Belle Collaboration. Compared to the first extraction, a more precise determination of the Collins fragmentation function and the transversity distribution function for u and d quarks is obtained.