Leading-twist single-transverse-spin asymmetries: Drell–Yan and deep-inelastic scattering

Recently, Brodsky, Hwang and Schmidt have proposed a new mechanism that gives a transverse spin symmetry at leading twist in semi-inclusive deep-inelastic scattering. I show that the new mechanism is compatible with factorization and is due to a transverse-spin asymmetry in the k T distribution of q...

Full description

Saved in:
Bibliographic Details
Published in:Physics letters. B 2002-05, Vol.536 (1), p.43-48
Main Author: Collins, John C.
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Recently, Brodsky, Hwang and Schmidt have proposed a new mechanism that gives a transverse spin symmetry at leading twist in semi-inclusive deep-inelastic scattering. I show that the new mechanism is compatible with factorization and is due to a transverse-spin asymmetry in the k T distribution of quarks in a hadron (the “Sivers asymmetry”). An earlier proof that the Sivers asymmetry vanishes because of time-reversal invariance is invalidated by the path-ordered exponential of the gluon field in the operator definition of parton densities. Instead, the time-reversal argument shows that the Sivers asymmetry is reversed in sign in hadron-induced hard processes (e.g., Drell–Yan), thereby violating naive universality of parton densities. Previous phenomenology with time-reversal-odd parton densities is therefore validated.
ISSN:0370-2693
1873-2445
DOI:10.1016/S0370-2693(02)01819-1