Single-Spin Asymmetries in Semi-inclusive Deep Inelastic Scattering and Drell-Yan Processes

Abstract

We examine in detail the diagrammatic mechanisms which provide the change of sign between the single transverse spin asymmetries measured in semi-inclusive deep inelastic scattering (SIDIS) and in the Drell-Yan process (DY). This asymmetry is known to arise due to the transverse spin dependence of the target proton combined with a T-odd complex phase. Using the discrete symmetry properties of transverse spinors, we show that the required complex phase originates in the denominators of rescattering diagrams and their respective cuts. For simplicity, we work in a model where the proton consists of a valence quark and a scalar diquark. We then show that the phases generated in SIDIS and in DY originate from distinctly different cuts in the amplitudes, which at first appears to obscure the relationship between the single-spin asymmetries in the two processes. Nevertheless, further analysis demonstrates that the contributions of these cuts are identical in the leading-twist Bjorken kinematics considered, resulting in the standard sign-flip relation between the Sivers functions in SIDIS and DY. Physically, this fundamental, but yet untested, prediction occurs because the Sivers effect in the Drell-Yan reaction is modified by the initial-state "lensing" interactions of the annihilating antiquark, in contrast to the final-state lensing which produces the Sivers effect in deep inelastic scattering.

40 pages, 15 figures

References in corpus (6)

• k_T factorization is violated in production of high-transverse-momentum particles in hadron-hadron collisions
• Measurement of Single and Double Spin Asymmetries in Deep Inelastic Pion Electroproduction with a Longitudinally Polarized Target
• Transverse Spin Structure of the Nucleon through Target Single Spin Asymmetry in Semi-Inclusive Deep-Inelastic $(e,e^{\prime }{\pi }^{\pm })$ Reaction at Jefferson Lab
• Connection between the Sivers function and the anomalous magnetic moment
• pT-Broadening and production processes versus dipole/quadrupole amplitudes at next-to-leading order
• Azimuthal angle dependence of di-jet production in unpolarized hadron scattering

Cited by in corpus (22)

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• Calculating TMDs of a Large Nucleus: Quasi-Classical Approximation and Quantum Evolution
• Transverse spin effects in hard semi-inclusive collisions
• When gluons go odd: how classical gluon fields generate odd azimuthal harmonics for the two-gluon correlation function in high-energy collisions
• Sivers Function in the Quasi-Classical Approximation
• Lensing Mechanism Meets Small-$x$ Physics: Single Transverse Spin Asymmetry in $p^{\uparrow }+p$ and $p^{\uparrow }+A$ Collisions
• Spin Physics through QCD Instantons
• Light-Front Holography, Color Confinement, and Supersymmetric Features of QCD
• Hadron Spectroscopy and Dynamics from Light-Front Holography and Superconformal Algebra
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• Transverse distortion of a relativistic composite system in impact parameter space
• QCD on the Light-Front -- A Systematic Approach to Hadron Physics
• Single Transverse Spin Asymmetries in Semi-inclusive Deep Inelastic Scattering in a Spin-1 Diquark Model
• Novel Corrections to the Momentum Sum Rule for Nuclear Structure Functions
• Predictions for the Sivers Single-Spin Asymmetry from Holographic QCD
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• Transverse Spin and Classical Gluon Fields: Combining Two Perspectives on Hadronic Structure
• Novel QCD Phenomena at JLab
• Supersymmetric Meson-Baryon Properties of QCD from Light-Front Holography and Superconformal Algebra