Wimpyc Calculates WIMP Capture Rates in Celestial Bodies, Extending WimPyDD for NREFT-based Direct Detection Studies

The search for dark matter relies on detecting its elusive interactions, and a new code, WimPyC, significantly advances calculations of how weakly interacting massive particles (WIMPs) might be captured within celestial bodies. Sunghyun Kang from Sogang University, Stefano Scopel also of Sogang University, and Gaurav Tomar from APJ Abdul Kalam Technological University, developed WimPyC as an extension to their existing WimPyDD code, enabling researchers to combine direct detection experiments with calculations of WIMP capture rates in planets and stars. This advancement allows for a more comprehensive investigation of dark matter interactions, accommodating various theoretical models and galactic velocity distributions, and crucially, the code’s modular design improves both the transparency and speed of these complex calculations. By separating the underlying physics into distinct components, WimPyC facilitates a more detailed and efficient exploration of the dark matter landscape.

We introduce WimPyC, a Python code for calculating the capture rate of Weakly Interacting Massive Particles (WIMPs) by celestial bodies through nuclear scattering in scenarios where the scattering process is considered to be in the thin regime. WimPyC extends the capabilities of the existing WimPyDD code, which calculates WIMP-nucleus scattering signals in direct detection experiments, and allows researchers to combine both direct detection and celestial capture calculations within a consistent theoretical framework. This framework utilizes Galilean-invariant non-relativistic effective theory, accommodating inelastic scattering, arbitrary WIMP spin, and a flexible description of the WIMP velocity distribution in the Galactic halo.

Dark Matter Constraints From Multiple Sources

Current research focuses on establishing robust constraints on dark matter properties by combining data from a variety of sources, moving beyond single detection methods to integrate limits from direct detection experiments, indirect detection searches, and studies of dark matter capture in celestial bodies. Researchers are also leveraging astrophysical observations to further refine these constraints. Investigations cover a wide range of dark matter candidates and interaction types, including Weakly Interacting Massive Particles (WIMPs), inelastic dark matter, anapole dark matter, and light dark matter. The research explores how efficiently dark matter can be captured by different celestial bodies, considering the scattering processes between dark matter particles and atomic nuclei, and accounting for the evaporation and annihilation of captured dark matter and the resulting signals.

Researchers treat various astrophysical objects, such as the Sun, Earth, white dwarfs, and Jupiter, as potential dark matter detectors, using their properties to constrain dark matter interactions. This work employs a multi-messenger approach, combining information from gamma rays, neutrinos, and direct detection events to obtain more robust constraints, and considers the internal structure of celestial bodies, such as core composition and temperature gradients, to accurately model dark matter capture and annihilation. Specific experiments and objects under investigation include LZ, a leading direct detection experiment, IceCube, a neutrino observatory, the Sun, Earth, white dwarfs, Jupiter, and the galactic center. This comprehensive approach represents a cutting-edge research effort in the field of dark matter, aiming to combine theoretical and observational data to understand the nature of this elusive substance.

WimPyC Calculates WIMP Capture Rates in Celestial Bodies

This work introduces WimPyC, a Python code designed to calculate the rate at which Weakly Interacting Massive Particles (WIMPs) are captured by celestial bodies through nuclear scattering, specifically in scenarios where the scattering process is considered to be in the thin regime. WimPyC builds upon the existing WimPyDD code, which calculates WIMP-nucleus scattering signals in direct detection experiments, and allows researchers to combine both direct detection and celestial capture calculations within a consistent theoretical framework. This framework utilizes Galilean-invariant non-relativistic effective theory, accommodating inelastic scattering, arbitrary WIMP spin, and a flexible description of the WIMP velocity distribution in the Galactic halo. The core achievement of WimPyC lies in its ability to factorize the capture rate calculation into three key components: Wilson coefficients representing the underlying particle physics, a response function describing the nuclear physics, and a halo function characterizing the WIMP velocity distribution.

These components are calculated and stored separately, enabling efficient interpolation and combination for signal evaluation, thereby improving both transparency and computational speed. Measurements within the code utilize the optical depth approximation to determine the capture rate, expressed as a function of WIMP mass and celestial body radius. The calculations incorporate the WIMP-nucleus differential scattering cross section, which is dependent on the WIMP and target spins, and the scattering amplitude, which is determined by Wilson coefficients and nuclear response functions. Specifically, the code accurately models the minimal and maximal recoil energies of WIMPs during scattering, and the velocity threshold for Inelastic Dark Matter scenarios, where WIMPs transition between different energy states. The code provides explicit expressions for the nuclear response functions, which are essential for modeling the scattering process in various targets, including those found in stars, planets, and white dwarfs. This advancement enables more precise modeling of WIMP capture in celestial bodies.

WimPyC Calculates Gravitational Capture Rates of Dark Matter

The development of WimPyC represents a significant advance in the study of dark matter, specifically weakly interacting massive particles, or WIMPs. Researchers created this Python code to calculate the rate at which WIMPs become gravitationally captured by celestial bodies through nuclear scattering, extending the capabilities of their existing WimPyDD code which focuses on direct detection experiments. WimPyC allows for the investigation of WIMP interactions in a wide range of scenarios, accommodating factors such as WIMP spin, inelastic scattering, and diverse galactic halo velocity distributions. This achievement lies in the code’s modular design, which separates the calculation into three key components: Wilson coefficients representing fundamental interaction strengths, nuclear response functions detailing nuclear physics, and halo functions describing WIMP velocity distributions.

By calculating and storing these components independently, WimPyC enhances both the transparency and speed of calculations, facilitating detailed phenomenological studies. The ability to combine direct detection signals with those from captured WIMPs within celestial bodies offers a potentially more sensitive approach to detecting these elusive particles. Researchers acknowledge that the accuracy of the code relies on the approximations used in the interpolation methods and the assumptions made about the underlying physics of dark matter interactions. Future research directions could focus on refining these approximations and exploring more complex models of dark matter distribution and interaction. Nevertheless, WimPyC provides a powerful new tool for investigating the nature of dark matter and its role in the universe.