Laser-assisted Light-by-Light Scattering in Born-Infeld and Axion-like Particle Theories

TL;DR

This work investigates laser-assisted light-by-light scattering as a low-energy probe of nonlinear QED and beyond-the-Standard-Model physics. By combining complete QED helicity amplitudes with Born–Infeld (BI) and axion-like particle (ALP) amplitudes, the authors compute interference patterns in the total cross section for gamma–laser collisions and identify regimes where the signal is observable with moderate luminosity. BI effects produce characteristic knee-like features due to destructive/constructive interference with QED, while ALPs introduce resonant enhancements near $oldsymbol{ extsqrt{s}} oughly m_a$ and potentially large on-shell production, yielding strong sensitivity to the coupling $g_{a extgamma extgamma}$ in the low-mass region. The study shows that laser-assisted LbL scattering can provide complementary constraints to LHC and beam-dump experiments, particularly at low invariant masses, and outlines practical experimental parameters and analyses to realize these searches.

Abstract

The precision measurements of well-known light-by-light reactions lead to important insights of nonlinear quantum electrodynamics (QED) vacuum polarization. The laser of an intense electromagnetic field strength provides an essential tool for exploring nonlinear QED and new physics beyond Standard Model (SM) in the high-precision frontier. In this work, we propose to search for low-energy light-by-light scattering in the collision of a photon beam and a laser pulse of classical background field. We aim to investigate the impact of Born-Infeld (BI) and axion-like particle (ALP) theories on laser-assisted light-by-light scattering. We calculate the QED light-by-light scattering cross section using complete QED helicity amplitudes, and then combine them with the amplitudes in BI or ALP theory to evaluate the total cross section. The laser-assisted SM light-by-light scattering should be observable in future experiments with very moderate integrated luminosities. The sensitivity of laser-assisted light-by-light scattering to BI and ALP parameters is presented.

Figures (9)

• Figure 1: Schematic diagram for the laser-assisted light-by-light scattering.
• Figure 2: The light-by-light scattering cross sections in BI theory as a function of c.m. energy $\sqrt{s}$ (left) and $\sqrt{b}$ (right). They include QED contribution (blue long-dashed line), BI contribution (cyan dash-dotted line), destructive interference (red dashed line), constructive interference (olive dashed line) and total cross section (black solid line). For illustration, we fix $\sqrt{b}=20m_e$ ($\sqrt{s}=0.34m_e$) on the left (right) panel.
• Figure 3: The differential cross sections $d\sigma/d\cos\theta$ in BI theory with $\sqrt{s}=0.34m_e$ and $\sqrt{b}=10m_e$ (left) or $\sqrt{b}=20m_e$ (right). They include QED contribution (blue long-dashed line), BI contribution (cyan dash-dotted line), destructive interference (red dashed line), and total cross section (black solid line).
• Figure 4: The differential cross sections $d\sigma/d\cos\theta_{\rm Lab}$ in BI theory with $\omega_\gamma =3.25 {\rm GeV}$, $\omega_L =2.35 {\rm eV}$, $\vartheta=10^\circ$ and $\sqrt{b}=10m_e$ (left) or $\sqrt{b}=20m_e$ (right). They include QED contribution (blue long-dashed line), BI contribution (cyan dash-dotted line), destructive interference (red dashed line), and the total contribution (black solid line).
• Figure 5: The light-by-light scattering cross sections in ALP theory as a function of c.m. energy $\sqrt{s}$ (top panels) and $m_a$ (bottom panel). They include QED contribution (blue long-dashed line), ALP contribution (cyan dash-dotted line), destructive interference (red dashed line), constructive interference (olive dashed line) and total cross section (black solid line). For illustration, we fix $g_{a\gamma\gamma}^{-1}=400m_e$, $m_a=0$ and $g_{a\gamma\gamma}^{-1}=400m_e$, $m_a=0.4 m_e$ ($\sqrt{s}=0.34m_e$, $g_{a\gamma\gamma}^{-1}=400m_e$) in the up (bottom) panels.