Halo-independent bounds on Inelastic Dark Matter

Abstract

We discuss halo-independent constraints on the Inelastic Dark Matter (IDM) scenario, in which a Weakly Interaction Massive Particle (WIMP) state $\chi$ with mass $m_{\chi }$ interacts with nuclear targets by upscattering to a heavier state ${\chi }^{\prime }$ with mass $m_{\chi }+\delta$. In order to do so we adopt the single-stream method, that exploits the complementarity of Direct Detection (DD) and Capture in the Sun to extend the experimental sensitivity to the full range of incoming WIMP speeds. We show that a non-vanishing mass splitting $\delta$ modifies such range, and that for particular combinations of $m_{\chi }$ and $\delta$ the complementarity between the two detection techniques required by the method is lost. Specifically, assuming for the escape velocity in our Galaxy $u_{esc}$ the reference value $u_{esc}^{ref}$ = 560 km/s a halo-independent bound is possible when $\delta \lesssim$ 510 keV for a Spin-Independent interaction and when $\delta \lesssim$ 245 keV for a Spin-Dependent interaction (with the Spin-Independent value slightly reduced to $\delta \lesssim$ 490 keV when $u_{esc}>u_{esc}^{ref}$). In the low-mass regime the bound from capture in the Sun is always more constraining than that for DD and is sufficient alone to provide a halo-independent constraint, while for large WIMP masses the halo-independent bound is given by a combination of capture in the Sun and DD. We also find that, for $u_{esc}$ = $u_{esc}^{ref}$, unless the mass of the target used in DD is larger than about four times that of the target driving capture in the Sun, DD does not play any role in the determination of the maximal value of $\delta$ for which a halo-independent bound is possible. We also discuss the issue of thermalization of IDM within the Sun and show that its impact on our results is mild.

32 pages and 11 figures. Discussion on thermalization added. Updated to published version

References in corpus (18)

• First Dark Matter Search Results from the LUX-ZEPLIN (LZ) Experiment
• The RAVE Survey: Constraining the Local Galactic Escape Speed
• Dark Matter Search Results from the Complete Exposure of the PICO-60 C${}_3$F${}_8$ Bubble Chamber
• Exothermic Dark Matter
• Interpreting Dark Matter Direct Detection Independently of the Local Velocity and Density Distribution
• Capture of Inelastic Dark Matter in the Sun
• Taking Halo-Independent Dark Matter Methods Out of the Bin
• Search for GeV-scale Dark Matter Annihilation in the Sun with IceCube DeepCore
• Bounds on Long-lived Dark Matter Mediators from Neutron Stars
• Quantifying (dis)agreement between direct detection experiments in a halo-independent way
• Electroweakly-Interacting Dirac Dark Matter
• A systematic halo-independent analysis of direct detection data within the framework of Inelastic Dark Matter
• Studying generalised dark matter interactions with extended halo-independent methods
• What is the probability that direct detection experiments have observed Dark Matter?
• Capture of Electroweak Multiplet Dark Matter in Neutron Stars
• Probing WIMP particle physics and astrophysics with direct detection and neutrino telescope data
• Halo-independent bounds on the non-relativistic effective theory of WIMP-nucleon scattering from direct detection and neutrino observations
• A halo-independent lower bound on the dark matter capture rate in the Sun from a direct detection signal

Cited by in corpus (4)

• Low-mass constraints on WIMP effective models of inelastic scattering using the Migdal effect
• Sensitivity of WIMP bounds on the velocity distribution in the limit of a massless mediator
• Information divergences to parametrize astrophysical uncertainties in dark matter direct detection
• Information-theoretic astrophysical uncertainties in the effective theory of dark matter direct detection