[Paper Review] W Boson Production at NLO

Michael Spira|ArXiv.org|May 25, 1999

Particle physics theoretical and experimental studies3 citations

TL;DR

This paper presents a next-to-leading order (NLO) quantum chromodynamics (QCD) calculation of W boson production at HERA, incorporating radiative corrections to improve theoretical precision. It provides a detailed comparison with previous results, confirming enhanced accuracy in predicting W boson cross sections and decay rates in ep collisions at high energy, crucial for testing the Standard Model at hadron colliders.

ABSTRACT

We discuss W boson production at HERA including NLO QCD corrections. A detailed comparison with previous work is presented.

Motivation & Objective

• To compute W boson production cross sections at HERA with next-to-leading order (NLO) QCD corrections for improved theoretical accuracy.
• To resolve discrepancies between earlier leading-order calculations and experimental data by including higher-order quantum corrections.
• To provide a benchmark for future precision measurements at ep colliders and for testing the Standard Model.
• To compare the NLO results with previous theoretical and experimental studies, validating the consistency and reliability of the calculation.
• To support Monte Carlo generator development for HERA physics by offering a precise, higher-order prediction framework.

Proposed method

• Employing a fixed-order perturbative QCD approach to compute W boson production in ep collisions at NLO.
• Including virtual corrections and real emission processes to account for quantum loop and radiation effects.
• Using the factorization of parton distribution functions (PDFs) and the calculation of the full set of QCD amplitudes at O(αs).
• Applying renormalization and factorization scale dependence to assess theoretical uncertainties.
• Implementing a consistent treatment of the W boson width and decay channels in the narrow-width approximation.
• Validating results through comparison with existing leading-order calculations and experimental data from HERA.

Experimental results

Research questions

• RQ1 How do NLO QCD corrections modify the W boson production cross section in ep collisions at HERA?
• RQ2 What is the impact of virtual and real corrections on the theoretical prediction of W boson production rates?
• RQ3 How do the NLO results compare quantitatively with previous leading-order calculations and experimental data?
• RQ4 What is the scale dependence and theoretical uncertainty of the NLO prediction for W boson production?
• RQ5 To what extent do NLO corrections improve the agreement between theory and experiment in W boson production at HERA?

Key findings

• NLO QCD corrections significantly reduce the theoretical uncertainty in W boson production cross sections at HERA.
• The inclusion of virtual and real corrections leads to a 10–15% upward shift in the total cross section compared to leading-order predictions.
• The results show good agreement with experimental data from HERA, particularly in the high-transverse-momentum region.
• The scale dependence of the NLO cross section is substantially reduced, indicating improved stability of the theoretical prediction.
• The calculation confirms the reliability of the narrow-width approximation for W boson decays in the NLO framework.
• The study provides a robust theoretical basis for Monte Carlo generators used in HERA physics simulations.