Constraining the Symmetron Model with the HUST-2020 Torsion Pendulum Experiment.

Area of Science:

• * Theoretical physics
• * Cosmology
• * Experimental gravity

Background:

• * The symmetron model proposes a mechanism for dynamically screening the coupling between scalar fields and matter.
• * High-density environments are crucial for probing such screening effects.
• * Short-range gravity experiments offer a unique avenue to test fundamental physics beyond the Standard Model.

Purpose of the Study:

• * To constrain the parameters of the symmetron model using experimental data.
• * To investigate the sensitivity of torsion pendulum experiments to the symmetron model.
• * To explore the implications of experimental results for dark energy and fundamental couplings.

Main Methods:

• * Analysis of data from the HUST-2020 torsion pendulum experiment.
• * Testing the inverse-square law of gravity at submillimeter ranges.
• * Applying constraints on the symmetron model's mass scale (μ) and self-coupling parameter (λ).

Main Results:

• * The HUST-2020 experiment is uniquely sensitive to the symmetron model with a mass scale of μ=7.2×10⁻³ eV.
• * The self-coupling parameter λ≲10⁵ is excluded at a mass scale M=0.3 TeV.
• * Constraints at the dark energy scale (μ=2.4×10⁻³ eV) were improved by approximately 10 times compared to previous torsion pendulum experiments.

Conclusions:

• * Torsion pendulum experiments provide powerful constraints on the symmetron model.
• * The study excludes specific parameter spaces for the symmetron model, particularly at high mass scales.
• * Future high-accuracy, short-range gravity experiments are essential for further probing scalar-tensor theories.