A Background-Free Search for Physics Beyond the Standard Model Using Atom Interferometry

A Background-Free Search for Physics Beyond the Standard Model Using Atom Interferometry Description This presentation outlines an experimental architecture adapting a large-baseline atom interferometer with a macroscopic electrostatic potential to perform a background-free search for anomalous gauge-gravity scalar couplings. Searching for Beyond Standard Model (BSM) physics at the intersection of gravity and electromagnetism is traditionally hindered by severe kinematic degeneracies, specifically the quadratic Stark shift. This proposed architecture transforms a mathematically degenerate quantum measurement problem into an achievable array of classical control requirements utilizing a "Four-Pillar" metrological approach: Geometric Exponential Suppression: Utilizing a Faraday tube to exponentially decay vector leakage fields, physically breaking the parity degeneracy. Double-Difference Lock-In Quadrature: A 4-point measurement cycle that algebraically annihilates gigaradian inertial gravitational phases and active high-pass filters low-frequency drift. Mid-Fringe Sweeping: Injecting an active optical phase shift to defeat fringe-peak rectification bias caused by massive environmental vibration noise. Optimal Spin-Squeezing: Utilizing Quantum Non-Demolition (QND) measurements to surpass the Standard Quantum Limit, achieving a ~20 dB noise reduction. The protocol is rigorously validated through ab initio 1D Split-Step Fourier Method (SSFM) simulations and a Monte Carlo noise engine, which successfully extracted a 28.2 μrad target signal with >10σ statistical confidence against extreme macroscopic drift. A statistically significant detection using this pristine null test would carry profound fundamental implications, including the breakdown of local gauge invariance, Equivalence Principle violations, and new empirical constraints on screened scalars and the Standard-Model Extension (SME). Full preprint paper:Cagnani, I. (2026). A Background-Free Search for Physics Beyond the Standard Model Using Atom Interferometry. Zenodo. https://doi.org/10.5281/zenodo.18896187