1. Holographic approach to the light-by-light contribution to the muon (g-2)
- Author
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Luigi Cappiello, G. D’Ambrosio, M. Iacovacci, S. Mastroianni, M. Passera and G. Venanzoni, and Cappiello, Luigi
- Subjects
Quantum chromodynamics ,Physics ,Particle physics ,Anomalous magnetic dipole moment ,010308 nuclear & particles physics ,QC1-999 ,Form factor (quantum field theory) ,Four-vector ,01 natural sciences ,Scattering amplitude ,Momento magnetico anomalo del muone, Modelli olografici della QCD ,Pion ,0103 physical sciences ,High Energy Physics::Experiment ,Tensor ,010306 general physics ,Pseudovector - Abstract
We discuss how holographic models of QCD are used to study the the hadronic light-by-light (HLbL) scattering amplitude contribution to the muon anomalous magnetic moment. After a brief description of the various models, we focus on a particular one, introduced by Hirn and Sanz, emphasizing the role it assigns to the pion, and the vector and-axial vector resonances. We review how the parameters of the model are fixed by imposing condition on the low energy and the deep Euclidean limit of two-point correlators of QCD vector and axial vector currents. We then focus on the evaluation of the three-point axial-vector-vector current correlator and the pion anomalous transition form factor to be used in the one-pion exchange HLbL diagram and study its asymptotic properties. Finally, we present preliminary results on the four vector current correlator that defines the Hadronic Light-by-Light tensor. We find that axial-vector resonances play an important rule in recovering the correct asymptotic behaviour predicted by QCD at large Euclidean momenta.
- Published
- 2020