Related Experiment Video
Updated: Oct 5, 2025
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Setting Limits on Supersymmetry Using Simplified Models
Published on: November 15, 2013
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Two-Loop Four-Fermion Scattering Amplitude in QED
R Bonciani1, A Broggio2, S Di Vita3,4
1Dipartimento di Fisica, Università di Roma "La Sapienza" and INFN Sezione di Roma, 00185 Roma, Italy.
Physical Review Letters
|January 28, 2022
Summary
This study provides the first full analytic calculation for a key quantum electrodynamics process. This advances precision measurements of the muon
Area of Science:
- Quantum Electrodynamics (QED)
- Particle Physics
- High-Energy Physics
Background:
- The anomalous magnetic moment of the muon (g-2)μ is a key observable in particle physics.
- Discrepancies exist between the Standard Model prediction and experimental measurements of (g-2)μ.
- Higher precision is needed to resolve this discrepancy.
Purpose of the Study:
- To perform a fully analytic two-loop evaluation of the transition amplitude for massless-to-massive fermion pair scattering.
- To provide a crucial component for improving the accuracy of electromagnetic coupling determinations.
- To enable a precise calculation of the leading hadronic contribution to (g-2)μ.
Main Methods:
- Fully analytic evaluation of scattering amplitudes.
- Two-loop calculations in quantum electrodynamics.
- Theoretical physics methods for precision calculations.
Main Results:
- The first fully analytic two-loop transition amplitude for the specified scattering process.
- An essential ingredient for enhanced accuracy in electromagnetic coupling determinations.
- A method to precisely determine the leading hadronic contribution to (g-2)μ.
Conclusions:
- The presented result is vital for the MUonE experiment at CERN.
- This work will help elucidate the discrepancy in the muon's anomalous magnetic moment.
- It advances the precision of theoretical predictions in particle physics.
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