Leading isospin breaking effects in the HVP contribution to a_μ and to the running of α

2021/12/01 by Andreas Risch, Risch, Andreas, Hartmut Wittig +1
Physics and Astronomy · Computer Science · #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #Computational Physics and Python Applications

paper · pdf · doi:10.48550/arxiv.2112.00878

Abstract

The anomalous magnetic moment of the muon a_μ and the running of the electromagnetic coupling α play a fundamental role in beyond Standard Model (SM) physics searches. Non-perturbative hadronic contributions to both quantities, which are related to the hadronic vacuum polarization (HVP) function consisting of two electromagnetic currents, are a main source of uncertainty in the SM prediction. We compute the HVP function in lattice QCD+QED applying the time-momentum representation method. We expand the relevant correlation functions around the isosymmetric limit. In particular, we focus on leading isospin breaking effects taking quark-connected contributions into account, which we evaluate on isosymmetric N_f=2+1 QCD gauge ensembles generated by the CLS initiative with non-perturbatively O(a)-improved Wilson fermions.

Related

• Isospin-breaking corrections to the muon magnetic anomaly in Lattice QCD
• Isospin breaking corrections to the HVP at the physical point
• QED and strong isospin corrections in the hadronic vacuum polarization contribution to the anomalous magnetic moment of the muon
• Valence leading isospin breaking contributions to a_μ^HVP-LO
• HVP contribution of the light quarks to the muon (g - 2) including isospin-breaking corrections with Twisted-Mass fermions