Some Recent Developments in 5th Force Searches

TL;DR

This paper emphasizes the importance of using diverse test samples in 5th force and WEP experiments to detect composition-dependent forces, highlighting past limitations and advocating for broader sample ranges in future tests.

Contribution

It highlights the potential limitations of current high-precision tests due to limited sample diversity and advocates for experiments with more varied samples to improve detection of new forces.

Findings

Pattern observed in EPF experiment data

Limited sample diversity may hinder detection of new forces

Call for experiments with broader sample ranges

Abstract

Recently we drew attention to the fact that most recent 5th force searches and tests of the weak equivalence principle (WEP) utilize only one or two pairs of test samples. We argue that, despite the great precision of these experiments, the lack of diversity of samples may mean they are unable to detect new composition-dependent forces, which requires the observation of a pattern in the data. Such a pattern was observed in the experiment by E\"{o}tv\"{o}s, Pek\'{a}r, and Fekete (EPF), the last high precision test of the WEP which used a significant number of different samples. We advocate for new experiments utilizing a sufficient number and range of samples to either confirm or refute the pattern found in the EPF experimental data.