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Gauge Coupling β Functions to Four-Loop Order in the Standard Model.

Joshua Davies1, Florian Herren1, Colin Poole2

  • 1Institut für Theoretische Teilchenphysik, Karlsruhe Institute of Technology (KIT), 76128 Karlsruhe, Germany.

Physical Review Letters
|March 7, 2020
PubMed
Summary
This summary is machine-generated.

We calculated the beta functions for standard model gauge couplings up to four-loop order. This research advances theoretical physics by precisely defining these functions in quantum field theory calculations.

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Area of Science:

  • High Energy Physics
  • Quantum Field Theory
  • Standard Model

Background:

  • The Standard Model describes fundamental particles and forces.
  • Gauge couplings determine interaction strengths.
  • Calculating beta functions is crucial for understanding renormalization and scale dependence.

Purpose of the Study:

  • To compute the beta functions of the three standard model gauge couplings to four-loop order.
  • To address the challenges of defining gamma_5 in dimensional regularization at higher loop orders.

Main Methods:

  • Modified minimal subtraction scheme (MS-bar) used for renormalization.
  • Calculation performed to four-loop order.
  • Gamma_5-dependent terms determined by exploiting relations with lower loop order coefficients.

Main Results:

  • The beta functions of the three standard model gauge couplings have been computed to four-loop order.
  • A method for handling gamma_5-dependent terms in dimensional regularization was successfully applied.

Conclusions:

  • The four-loop beta functions provide a more precise understanding of the Standard Model's behavior at high energy scales.
  • This work contributes to the ongoing effort to refine theoretical predictions in particle physics.