Simulations of the Angular Recoil-Energy Distribution of WIMP-Scattered Target Nuclei for Directional Dark Matter Detection Experiments

TL;DR

This study uses Monte Carlo simulations to analyze the angular and energy distributions of WIMP-induced nuclear recoils, emphasizing their anisotropy and modulation, to improve directional dark matter detection methods.

Contribution

It investigates the angular and energy distributions of WIMP recoils in different celestial coordinates, highlighting anisotropy and modulation effects based on target nucleus and WIMP mass.

Findings

Recoil distributions show significant anisotropy and annual modulation.

Distribution characteristics depend on target nucleus and WIMP mass.

Simulation results are available interactively online.

Abstract

In this paper, as the second part of the third step of our study on developing data analysis procedures for using 3-dimensional information offered by directional direct Dark Matter detection experiments in the future, we investigate the angular distributions of the recoil direction (flux) and the recoil energy of the Monte Carlo simulated WIMP-scattered target nuclei observed in different celestial coordinate systems. The "anisotropy" and the "directionality" ("annual" modulation) of the angular recoil-direction/energy distributions will be demonstrated. We will also discuss their dependences on the target nucleus and on the mass of incident halo WIMPs. For readers' reference, all simulation plots presented in this paper (and more) can be found "in animation" on our online (interactive) demonstration webpage (http://www.tir.tw/phys/hep/dm/amidas-2d/).