WIMP identification through a combined measurement of axial and scalar couplings
G. Bertone, D. G. Cerdeno, J. I. Collar, B. Odom
TL;DR
Direct detection of dark matter requires constraining both spin-independent and spin-dependent WIMP–nucleon cross sections, $\sigma_p^{\rm SI}$ and $\sigma_p^{\rm SD}$. The paper analyzes a COUPP-like detector with CF$_3$I and complementary targets (e.g., C$_4$F$_{10}$) to perform a combined measurement of axial and scalar couplings. It shows that sensitivity to both couplings increases the chance of initial detection and that comparing signals across targets allows a more precise determination of $\sigma_p^{\rm SI}$ and $\sigma_p^{\rm SD}$, enabling discrimination between neutralino and Kaluza-Klein dark matter. This multitarget approach informs detector strategy for accurately characterizing the DM particle and guides future ton-scale experiments.
Abstract
We study the prospects for detecting Weakly Interacting Massive Particles (WIMPs), in a number of phenomenological scenarios, with a detector composed of a target simultaneously sensitive to both spin-dependent and spin-independent couplings, as is the case of COUPP (Chicagoland Observatory for Underground Particle Physics). First, we show that sensitivity to both couplings optimizes chances of initial WIMP detection. Second, we demonstrate that in case of detection, comparison of the signal on two complementary targets, such as in COUPP CF3I and C4F10 bubble chambers, allows a significantly more precise determination of the dark matter axial and scalar couplings. This strategy would provide crucial information on the nature of the WIMPs, and possibly allow discrimination between neutralino and Kaluza-Klein dark matter.