Particle-Physics Implications of a Recent Test of the Gravitational Inverse-Square Law

We use data from our recent search for violations of the gravitational inverse-square law to constrain dilaton, radion, and chameleon exchange forces as well as arbitrary vector or scalar Yukawa interactions. We test the interpretation of the PVLAS Collaboration effect and a conjectured “fat-graviton” scenario and constrain the ${\gamma }_5$ couplings of pseuodscalar bosons and arbitrary power-law interactions.

Figure 1

95% confidence constraints on scalar or vector Yukawa interactions. Left vertical scale: vector interactions coupled to $B\mathrm{\text{−}}L$ (i.e., $\tilde{\psi }=\pi /2$); right vertical scale: scalar $\varphi \gamma \gamma$ couplings inferred as discussed below.

Figure 2

95% confidence constraints on couplings of a boson of mass $m{c}^2=1\mathrm{meV}$ as a function of the charge parameter $\tilde{\psi }$. Constraints for other values of $m$ can be found by using Fig. 1 to scale the couplings as a function of $m$.

Figure 3

Left: diagram of the process proposed to explain the PVLAS result [5]. Right: diagram of a related process that would give a signal in gravitational experiments. Wiggly and dashed lines are photons and scalar bosons, respectively.

Figure 4

$2\sigma$ constraints on the chameleon parameter $\beta$ as a function of $\gamma$ from the data of Ref. 1. The shaded area is ruled out at 95% confidence. The chameleon signal is strongest when the chameleon length scale is comparable to the 1 mm hole thickness. For much larger length scales, the field varies little over the pendulum and attractor, giving a weak signal. For length scales much smaller than the thickness of the BeCu foil, the signal is “screened” by the foil.

Figure 5

68%-confidence constraints on the ${\gamma }_5$ couplings of massive pseudoscalars to neutrons plotted against pseudoscalar mass $m$. The solid and dashed curves are from the ISL tests of Refs. 1, 15, respectively. The horizontal dotted line shows the SN 1987A constraint [8].