Lorentz Invariance Violation Alters Photon Interactions, Impacting Extragalactic Propagation And Atmospheric Shower Development

The fundamental principle of Lorentz invariance, which dictates that the laws of physics remain constant for all observers, faces ongoing scrutiny from physicists seeking a more complete understanding of the universe. Denise Boncioli, from Università degli Studi dell’Aquila and Istituto Nazionale di Fisica Nucleare, Valdir Barbosa Bezerra, from the Federal University of Paraíba, and Matteo Giammarco, also from Università degli Studi dell’Aquila and Istituto Nazionale di Fisica Nucleare, alongside Iarley Pereira Lobo, Pedro Morais, and Francesco Salamida from the Federal University of Paraíba, investigate how violations of this principle affect the journey of high-energy photons. Their work explores the consequences of Lorentz invariance violation both during the long voyage of photons across vast intergalactic distances and within the Earth’s atmosphere, demonstrating how such violations alter key characteristics of photon interactions and potentially create unique signatures in extensive air showers. By modelling these effects, the team reveals that even subtle deviations from established physics can measurably impact astroparticle propagation and photon dynamics, opening new avenues for testing fundamental theories through future high-energy astrophysical observations.

Scientists investigate the consequences of this symmetry violation on photon interactions, considering both the vast distances photons travel through intergalactic space and their interactions within Earth’s atmosphere and crust. The study employs a framework that incorporates modifications to how photons propagate, allowing for a detailed assessment of potential signatures of new physics. The research focuses on how Lorentz invariance violation alters key aspects of photon behavior, such as the probability of interactions and the energy required for certain processes to occur.

By modelling these effects, scientists analyse how the observed spectra of ultra-high energy photons might deviate from standard predictions. Furthermore, the study examines the characteristics of extensive air showers, like the timing of Cherenkov radiation, to identify potential effects of Lorentz invariance violation on shower development. Results demonstrate that this symmetry violation can induce measurable changes in both the spectra of ultra-high energy photons and the characteristics of extensive air showers, offering potential avenues for experimental verification. The research investigates intergalactic photon propagation, specifically through the creation of electron-positron pairs, and atmospheric interactions via the Bethe-Heitler process.

By incorporating Lorentz invariance violation into the theoretical framework, the study analyses how it modifies key quantities such as the probability of interactions and the energy threshold for these processes. Furthermore, the impact of Lorentz invariance violation on extensive air showers initiated by high-energy photons is studied, demonstrating that it can alter the cross section of the primary interaction in the atmosphere. The team also tests photon interactions within the Earth’s crust, to evaluate the potential induction of upward-going showers. The results highlight the necessity of accounting for both propagation effects and Lorentz invariance violation when modelling high-energy photon behaviour.

Lorentz Violation Impacts Ultrahigh Energy Photons

This paper investigates the potential effects of Lorentz invariance violation on the propagation and detection of ultra-high energy photons, focusing on how this symmetry violation might alter the observed flux of these particles. The goal is to explore how Lorentz invariance violation might change the observed flux of ultra-high energy photons and to assess the constraints that can be placed on Lorentz invariance violation parameters using observational data from experiments like the Pierre Auger Observatory and IceCube. The research combines theoretical calculations with observational constraints to explore the implications of Lorentz invariance violation for astroparticle physics. The central hypothesis is that Lorentz invariance, a cornerstone of special relativity, might be slightly violated at very high energies.

This violation could manifest as energy-dependent changes in the speed of light or other fundamental constants. The research focuses on how Lorentz invariance violation might affect the propagation of ultra-high energy photons through intergalactic space and their interactions within the Earth’s atmosphere and crust. Key mechanisms considered include the Bethe-Heitler process and pair production, which govern photon attenuation and shower development. The research employs a combination of theoretical calculations and numerical simulations. The authors develop theoretical models to describe how Lorentz invariance violation might affect photon propagation, interaction cross-sections, and shower development.

They calculate the cross-sections for relevant photon-nucleus interactions, taking into account the potential effects of Lorentz invariance violation. They use numerical simulations to model the development of electromagnetic showers in the atmosphere and within the Earth’s crust. They calculate the expected flux of ultra-high energy photons at the Earth’s surface, taking into account the effects of Lorentz invariance violation on propagation and interactions. They compare their theoretical predictions with observational data from the Pierre Auger Observatory and IceCube to constrain the parameters of Lorentz invariance violation.

Lorentz invariance violation can significantly alter the propagation of ultra-high energy photons through intergalactic space and their interactions within the Earth’s atmosphere and crust. Atmospheric suppression of showers is a crucial factor in determining the observed flux of ultra-high energy photons. The Earth’s crust can act as a potential medium for detecting ultra-high energy photons, with the possibility of observing upward-going showers. The research places constraints on the parameters of Lorentz invariance violation based on the comparison between theoretical predictions and observational data. The study highlights the importance of considering the combined effects of Lorentz invariance violation on both propagation and detection stages to obtain robust constraints on Lorentz invariance violation parameters. Including atmospheric suppression in the calculations reduces the expected photon flux, aligning the curves with the measured upper limits from the Pierre Auger Observatory.

Lorentz Violation Alters Photon Propagation and Interactions

This research investigates how violations of Lorentz invariance, a fundamental symmetry of physics, affect the behaviour of high-energy photons travelling through space and interacting with Earth. Scientists determined that even slight deviations from this established symmetry can measurably alter key characteristics of photon propagation, including the probability of interactions and the energy thresholds for certain processes. The study considered both the long distances photons travel through intergalactic space and their interactions within Earth’s atmosphere and crust. The team’s calculations demonstrate that Lorentz invariance violation can modify the cross section for photon interactions, potentially enhancing the production of upward-going showers within Earth’s crust.

By modelling these effects, researchers were able to predict how the observed flux of photons might be altered, and compared these predictions to existing upper limits on neutrino flux established by experiments like IceCube and the Pierre Auger Observatory. Results indicate that accounting for atmospheric suppression reduces the expected photon flux, bringing theoretical predictions closer to observational constraints. The authors acknowledge that their models rely on approximations of Earth’s density profile and that further refinement is needed. Future work should focus on more detailed modelling of these complex interactions and exploring a wider range of Lorentz invariance violation parameters. Despite these limitations, this research establishes a novel approach to constrain potential violations of fundamental symmetries using high-energy astrophysical observations and provides a valuable framework for interpreting data from ongoing and future experiments.