Constraining nonlinear corrections to Maxwell electrodynamics using γ γ scattering

• Autor(a) principal: Medeiros, Léo Gouvêa
• Data de Publicação: 2019
• Outros Autores: Akmansoy, Pierre Niau
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRN
• Texto Completo: https://repositorio.ufrn.br/jspui/handle/123456789/29895
• topic: Nonlinear corrections; Maxwell electrodynamics; γ γ scattering

The recent light-by-light scattering cross section measurement made by the ATLAS Collaboration is used to constrain nonlinear corrections to Maxwell electrodynamics parametrized by the Lagrangian L 1⁄4 F þ 4αF2 þ 4βG2 þ 4δFG. The ion’s radiation is described using the equivalent photon approximation, and the influence of four different nuclear charge distributions is evaluated. Special attention is given to the interference term between the Standard Model and the nonlinear corrections amplitudes. By virtue of the quadratic dependence on α, β, and δ, the nonlinear contribution to the Standard Model γγ cross section is able to delimit a finite region of the parameter’s phase space. The upper values for α and β in this region are of order 10−10 GeV−4, a constraint of at least 12 orders of magnitude more precise when compared to low-energy experiments. An upper value of the same order for δ is obtained for the first time in the LHC energy regime. We also give our predictions for the Standard Model cross section measured at ATLAS for each distribution and analyze the impact of the absorption factor. We finally give predictions for the future measurements to be done with upgraded tracking acceptance jηj < 4 by the ATLAS Collaboration