Force sensor for chameleon and Casimir force experiments with parallel-plate configuration

Abstract

PreprintVersionThe search for non-Newtonian forces has been pursued following many different paths. Recently it was suggested that hypothetical chameleon interactions, which might explain the mechanisms behind dark energy, could be detected in a high-precision force measurement. In such an experiment, interactions between parallel plates kept at constant separation could be measured as a function of the pressure of an ambient gas, thereby identifying chameleon interactions by their unique inverse dependence on the local mass density. During the past years we have been developing a new kind of setup complying with the high requirements of the proposed experiment. In this article we present the first and most important part of this setup -the force sensor. We discuss its design, fabrication, and characterization. From the results of the latter we derive limits on chameleon interaction parameters that could be set by the forthcoming experiment. Finally, we describe the opportunity to use the same setup to measure Casimir forces at large surface separations with unprecedented accuracy, thereby potentially giving unambiguous answers to long standing open questions.

Atomic interferometry test of dark energy

“…Stringent constraints [27][28][29] follow from torsion pendulum experiments such as Eötwash [30,31] where the presence of new forces can be tested [32]. Another promising technique uses the potential deviation from the Casimir interaction [7,33] between two plates [34,35]. Forthcoming experiments such as CANNEX may potentially exclude all models of the inverse chameleon type [36].…”

Recent breakthrough and outlook in constraining the non-Newtonian gravity and axion-like particles from Casimir physics

“…As shown above, the proposed minor modifications of already performed experiments make possible obtaining even stronger constraints. In future, more radical improvements in the laboratory setups may be employed (for instance, by using the test bodies with aligned nuclear spins [43] or a large area force sensor suggested for constraining chameleon interactions [44]). …”

Quartic chameleons: Safely scale-free in the early Universe

“…The value of the kick function then drops to Σ ≪ 1, and φ min is pushed to significantly smaller field values; see Eq. (8). For all reheat temperatures much less than M Pl we can assume that the chameleon begins at rest with φ equal to the value of φ min just prior to the drop in Σ, because m 2 ≫ H 2 , as shown in Eq.…”

“…Experiments that use atom [4] and neutron [5,6] interferometry and those that use µm-sized test masses [7] have already placed constraints on chameleon theories. Additional experiments have been proposed: one aims to measure the interactions between parallel plates to search for new forces [8] and another suggests using atom interferometry between parallel plates of different densities to detect density-dependent chameleon forces [9]. Laboratory searches for chameleon particles converted from photons in the presence of a magnetic field via the Primakov effect have placed constraints on the chameleon-photon coupling [10,11].…”

“…While we will show that the field still finds its minimum prior to the kicks, it is not strictly necessary to avoid endangering the success of BBN. Equation (8) implies that φ min is proportional to the cube root of the energy density in radiation and so will decay as a −4/3 . Thus, φ min will decrease faster than the oscillation amplitude by a factor of a −1/3 , implying that the value of φ at the maximum of its oscillations will always exceed the minimum of its effective potential.…”