Induced Violation of Weak Equivalence Principle in the Brans-Dicke Theory

TL;DR

This paper investigates how quantum corrections in Brans-Dicke theory can lead to violations of the Weak Equivalence Principle, providing new constraints on the theory's parameters based on potential experimental bounds.

Contribution

It introduces a quantum correction mechanism in Brans-Dicke theory that results in WEP violation, establishing more stringent bounds on the parameter .

Findings

Lower bounds on  are ^6 for force-range > 1m

Lower bounds on  are ^8 for force-range > 1AU

Quantum effects can significantly constrain scalar-tensor theories

Abstract

A quantum correction to the Brans-Dicke theory due to interactions among matter fields is calculated, resulting in violation of WEP, hence giving a constraint on the parameter $\omega$ far more stringent than accepted so far. The tentative estimate gives the lower bounds $\gsim 10^{6}$ and $\gsim 10^{8}$ for the assumed force-range $\gsim 1$m and $\gsim 1$AU, respectively.