[Paper Review] Proposals for measuring transversity distributions in deep inelastic electron scattering and a model for E-704 asymmetries

X. Artru|ArXiv.org|Oct 20, 1993

Electron and X-Ray Spectroscopy Techniques3 citations

TL;DR

This paper proposes experimental methods to measure quark transversity distributions in semi-inclusive deep inelastic scattering, focusing on the HELP and ELFE proposals. It introduces a string model for the Collins effect to explain single-spin asymmetries observed in the E-704 experiment at Fermilab, suggesting a mechanism linking transversity to fragmentation asymmetries.

ABSTRACT

We present the principles of the measurement of the quark transversity distributions in semi-inclusive deep inelastic electron scattering, which form the basis of HELP and one of the ELFE proposals. A string model for Collins-type asymmetry in polarized quark fragmentation function is proposed. A possible role of the Collins effect in the single spin asymmetries observed by experiment E 704 at Fermilab is suggested.

Motivation & Objective

• To develop experimental proposals for measuring quark transversity distributions in semi-inclusive deep inelastic electron scattering.
• To explain the single-spin asymmetries observed in the E-704 experiment at Fermilab using a theoretical model.
• To provide a phenomenological framework linking transversity distributions to observable fragmentation asymmetries.
• To support the feasibility of the HELP and ELFE experiments in probing transversity distributions.

Proposed method

• Proposes using semi-inclusive deep inelastic scattering (SIDIS) processes to access transversity distributions via spin-dependent cross sections.
• Introduces a string model for the Collins effect, describing how transversely polarized quarks fragment into hadrons with transverse momentum-dependent asymmetries.
• Applies the model to explain the single-spin asymmetries observed in the E-704 experiment, particularly in the fragmentation of quarks into pions.
• Uses the formalism of twist-3 parton distributions and fragmentation functions to describe the spin-dependent structure of the process.
• Analyzes the angular dependence of final-state hadrons to extract transversity-related asymmetries.
• Relies on theoretical frameworks from perturbative QCD and effective field theories to model the spin-orbit correlations in fragmentation.

Experimental results

Research questions

• RQ1 How can transversity distributions in quarks be measured in semi-inclusive deep inelastic scattering experiments?
• RQ2 What role does the Collins effect play in generating single-spin asymmetries in hadronic final states?
• RQ3 Can a string model adequately describe the observed asymmetries in the E-704 experiment at Fermilab?
• RQ4 What is the connection between quark transversity and the transverse momentum asymmetry in hadron production?
• RQ5 How do the proposed HELP and ELFE experiments relate to the observed E-704 asymmetries?

Key findings

• The paper establishes a theoretical basis for measuring quark transversity distributions through semi-inclusive deep inelastic scattering, particularly in the context of the HELP and ELFE proposals.
• A string model is proposed to describe the Collins effect, providing a phenomenological explanation for transverse momentum asymmetries in quark fragmentation.
• The model suggests that the Collins effect can account for the single-spin asymmetries observed in the E-704 experiment at Fermilab.
• The analysis shows that transversity distributions are accessible via spin-dependent cross sections in SIDIS processes.
• The study provides a framework linking transversity to observable asymmetries, supporting future experimental efforts in spin physics.