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Nuclear Modification of Transverse Momentum Dependent Parton Distribution Functions by a Global QCD Analysis
Mishary Alrashed1, Daniele Anderle1,2,3, Zhong-Bo Kang1,4,5
1Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA.
Physical Review Letters
|December 23, 2022
Summary
This study presents the first global QCD extraction of nuclear parton distribution and fragmentation functions. It analyzes data from electron-nucleus scattering and Drell-Yan production, providing insights into nuclear parton structure.
Area of Science:
- Quantum Chromodynamics (QCD)
- High-Energy Nuclear Physics
- Parton Physics
Background:
- Understanding the structure of nucleons and nuclei at high energies is crucial.
- Transverse Momentum Dependent (TMD) parton distribution functions (PDFs) and fragmentation functions (FFs) describe this structure.
- Previous studies have focused on free nucleons, with limited extractions for nuclear environments.
Purpose of the Study:
- To perform the first simultaneous global Quantum Chromodynamics (QCD) extraction of TMD parton distribution functions (PDFs) and TMD fragmentation functions (FFs) in nuclei.
- To analyze the impact of nuclear matter on parton properties.
- To provide predictions for future experimental programs.
Main Methods:
- Global analysis of world data from semi-inclusive electron-nucleus deep inelastic scattering and Drell-Yan dilepton production.
- Utilized data from HERMES, Fermilab, RHIC, and LHC (90 data points total).
- Performed calculations at next-to-leading order and next-to-next-to-leading logarithmic accuracy.
Main Results:
- Achieved a statistically significant fit with χ²/d.o.f. = 1.196.
- Successfully extracted nuclear-modified TMDs for the first time.
- Compared the extracted nuclear TMDs with those of free nucleons, revealing modifications.
Conclusions:
- This work establishes a robust framework for studying nuclear parton structure using TMDs.
- The results provide essential input for interpreting current and future experiments at facilities like JLab and the Electron-Ion Collider.
- The findings contribute to a deeper understanding of Quantum Chromodynamics in the nuclear medium.
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