Testing the equivalence principle in the field of the Earth: Particle physics at masses below 1 μeV\?
Abstract
A sensitive, systematic search for feeble, macroscopic forces arising from the exchange of hypothetical ultra-low-mass bosons was made by observing the differential acceleration of two different test body pairs toward two different sources. Our differential accelerometer-a highly symmetric, continuously rotating torsion balance-incorporated several innovations that effectively suppressed systematic errors. All known sources of systematic error were demonstrated to be negligible in comparison to our fluctuating errors which are roughly 7 times larger than the fundamental limit set by the fact that we observe an oscillator at room temperature with a given damping time. Our 1σ limits on the horizontal differential acceleration of Be/Al or Be/Cu test body pairs in the field of the Earth, Δa⊥=(2.1+/-2.1)×10-11 cm s-2 and Δa⊥=(0.8+/-1.7)×10-11 cm s-2, respectively, set improved bounds on Yukawa interactions mediated by bosons with masses ranging between mbc2~=3×10-18 and mbc2~=1×10-6 eV. For example, our constraints on infinite-range vector interactions with charges of B and of B-L are roughly 10 and 2 times more sensitive than those obtained by Roll, Krotkov, and Dicke using the field of the Sun. Furthermore we set stringent constraints down to λ=1 m, while those of solar experiments are weak for λ<1 AU. In terms of the weak equivalence principle in the field of the Earth, our 1σ result corresponds to mi/mg(Cu)-mi/mg(Be)=(0.2+/-1.0)×10-11. Our results also yield stringent constraints on the nonsymmetric gravitation theory of Moffat and on the anomalous acceleration of antimatter in proposed ``quantum gravity'' models, and have implications for lunar-ranging tests of the strong equivalence principle. Our 1σ limit on the differential acceleration of Be/Al test body pairs toward a 1.5 Mg Pb laboratory source, Δa=(-0.15+/-1.31)×10-10 cm s-2, provides constraints on Yukawa interactions with ranges down to 10 cm, and on interactions whose charge is B-2L.
- Publication:
-
Physical Review D
- Pub Date:
- November 1990
- DOI:
- 10.1103/PhysRevD.42.3267
- Bibcode:
- 1990PhRvD..42.3267A