Potential of constraining the Fifth Force Using the Earth as a Spin and Mass Source from space

Abstract

We explore the potential of conducting an experiment in a low Earth orbit spacecraft and using the Earth a spin and mass source to constrain beyond-the-standard-model (BSM) long-range spin- and velocity-dependent interactions, which are mediated by the exchange of an ultralight $\left(m_{Z^{\prime}}<10^{-10}\text{eV}\right)$ or massless intermediate vector boson. The high speed of the low Earth orbit spacecraft can enhance the sensitivity to velocity-dependent interactions. The periodicity enables efficient extraction of signals from background noise, thereby improving the experiment's accuracy. Combining these advantages, we demonstrate theoretically that the novel Spacecraft-Earth model can improve existing bounds on these exotic interactions by up to three orders of magnitude, using the China Space Station (CSS) as a representative low-Earth-orbit carrier. Such a model, if successfully implemented, may provide an innovative strategy for detecting ultralight dark matter and yield tighter constraints on certain coupling constants of exotic interactions.

Figures (6)

• Figure 1: Schematic layout of a space-based experiment. $\widehat{\boldsymbol{\sigma}}_{1}$ represents the spin-sensitive direction of the apparatus on a low Earth orbit spacecraft, which is fixed geographically northward(N) or eastward(E), respectively. $\widehat{\boldsymbol{\sigma}}_{2}$ represents the direction opposite to the geomagnetic field. $\mathbf{r}_{\mathrm{s}}^{\prime}$ and $\mathbf{r}^{\prime}$ represent the radial position of the spacecraft and the geoelectron, respectively. $\mathbf{r}_{\mathrm{s}}^{\prime} - \mathbf{r}^{\prime}$ is the relative position.
• Figure 2: Periodicity of the expected signals with the assumption that one can use the CSS as the spacecraft. The starting point of the Time axis is arbitrarily chosen to be July $1^{st}$, 2024.
• Figure 3: Contour plots of the potentials expected as a spacecraft (CSS) travels from south to north. (a) $V_{6}$. (b) $V_{7}$. (c) $V_{8}$. (d) $V_{14}$. (e) $V_{15}$. (f) $V_{16}$.
• Figure 4: Expected bounds on long-range spin-spin velocity-dependent couplings for electron-electron ($e$-$e$) interactions. The blue curves represent the expected constraints, assuming an arbitrary sensitivity condition (e.g., $10^{-20}$ eV), where the result is the combination of the sensor heading East (E) and North (N) during detection. (a) Vector-axial (V-A) couplings [Eq. \ref{['67']} with the $+$ sign] for $V_{6}$. (b) (V-A) couplings [Eq. \ref{['67']} with the $-$ sign ] for $V_{7}$. (c) (A-A) couplings [Eq. \ref{['8']}] for $V_{8}$. (d) (A-A) couplings [Eq. \ref{['14']}] for $V_{14}$. (e) (V-V) couplings [Eq. \ref{['15']}] for $V_{15}$. (f) (V-A) couplings [Eq. \ref{['16']}] for $V_{16}$.
• Figure 5: Same as Fig. \ref{['bound']} but for $V_{6+7}$.