2012/01/13 by Kevin T. Engel, Hiren H. Patel, Michael J. Ramsey-Musolf · 33 citations
Physics and Astronomy · #Amplitude #Anomalous magnetic dipole moment #Chiral perturbation theory #Hadron #High-Energy Particle Collisions Research #Muon #Order (exchange) #Particle physics #Particle physics theoretical and experimental studies #Perturbation theory (quantum mechanics) #Perturbative QCD #Photon #Physics #Pion #Polarizability #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #Quantum electrodynamics #Quantum mechanics #Scattering #Scattering amplitude #hep-ph
paper · pdf · doi:10.1103/physrevd.86.037502
published in Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields 86(3) (American Physical Society) · 4 pages, 1 figure
arxiv created 2012/01/13 · openalex publication_date 2012/08/27 · arxiv updated 2013/05/29 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We compute the charged pion loop contribution to the light-by-light scattering amplitude for off-shell photons in chiral perturbation theory through next-to-leading order (NLO). We show that for small photon virtualities (k2\ensuremath≪m_\ensuremathπ2) the NLO contributions are relatively more important due to an accidental numerical suppression of the LO terms. This behavior is consistent with previous calculations of the hadronic light-by-light contribution to the muon anomalous magnetic moment, a_\ensuremathμHLBL, whose leading order value receives O(1) corrections from models incorporating some of the NLO physics. We also show that models employed thus far for the charged pion loop contribution to a_\ensuremathμHLBL are not fully consistent with low-momentum behavior implied by quantum chromodynamics, having omitted potentially significant contributions from the pion polarizability.