Constraining nonlinear corrections to Maxwell electrodynamics using γγ scattering

Abstract

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 = F + 4αF 2 + 4βG 2 + 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, 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 |η| < 4 by the ATLAS Collaboration.

Observation of Light-by-Light Scattering in Ultraperipheral Pb+Pb Collisions with the ATLAS Detector

“…Relevant examples are magnetic monopoles [3], vector-like fermions [4] and axion-like particles [5,6]. The light-by-light cross section is also sensitive to the effect of possible non-SM operators in an effective field theory [7][8][9]. Light-by-light scattering graphs with electron loops also contribute to the anomalous magnetic moment of the electron and muon [10,11].Strong evidence for this process in relativistic heavy-ion (Pb+Pb) collisions at the Large Hadron Collider (LHC) has been reported by the ATLAS [12] and CMS [13] collaborations with observed significances of 4.4 and 4.1 standard deviations, respectively.…”

Probing CP violation in photon self-interactions with cavities

“…(2.1) is valid. At such energies the EFT coefficients for photon self-interactions, including their CPV part, have been constrained to be b BSM , c BSM , d BSM 10 −10 GeV −4 , see [34].…”

Bounds on the scale of noncommutativity from mono photon production in ATLAS Runs -1 and -2 experiments at LHC energies

“…Recently, the ATLAS measurements of light-by-light scattering (𝛾𝛾 ⟶ 𝛾𝛾) in Pb-Pb collisions [29,30], which is the first direct evidence for this process, imposed a strong constraint on Born-Infeld Theory [31] and on nonlinear Lorentz-violating effects in electrodynamics [32]. These same scattering cross section measurements are used to obtain the most precise constraints for nonlinear corrections to Maxwell electrodynamics [33]. NCQED cross section calculations show that the current ATLAS experiment at a center-of-mass energy of √ 𝑠 𝑁𝑁 = 5.02 𝑇𝑒𝑉 can only probe 𝛬 < 100 𝐺𝑒𝑉 region, however the next generation hadron colliders (such as the SppC) could have the potential to probe the non-commutative scale up to ∼ 300 GeV [34].…”