Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userDark Matter Substructure under the Electron Scattering Lamppost
60
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
We study the mutual relationship between dark matter-electron scattering experiments and possible new dark matter substructure nearby hinted by the Gaia data. We show how kinematic substructure could affect the average and modulation spectra of dark matter-electron scattering in semiconductors, and the discovery reaches of future experiments with these targets. Conversely, we demonstrate how future data could probe and constrain the substructure dark matter fraction, even when it constitutes a sub-dominant component of the local dark matter density.
rate research
Read More
We present a detailed analysis of the effect of light Dark Matter (DM) on atomic clocks, for the case where DM mass and density are such that occupation numbers are low and DM must be considered as particles scattering off the atoms, rather than a classical field. We show that the resulting atomic clock frequency shifts are first order in the scattering amplitudes, and particularly suited to constrain DM models in the regime where the DM mass $m_chi ll$ GeV. We provide some rough order of magnitude estimates of sensitivity that can be confronted to any DM model that allows for non zero differential scattering amplitudes of the two atomic states involved in the clock.
We present a novel mechanism for Sommerfeld enhancement for dark matter interactions without the need for light mediators. Considering a model for two-component scalar dark matter with a triple coupling, we find that there appears an $u$-channel resonance in dark matter elastic scattering. From the sum of the corresponding ladder diagrams, we obtain a Bethe-Salpeter equation with a delay term and identify the Sommerfeld factor for two-component dark matter from the effective Yukawa potential for the first time. We discuss the implications of our results for enhancing dark matter self-scattering and annihilation.
We extend the calculation of dark matter direct detection rates via electronic transitions in general dielectric crystal targets, combining state-of-the-art density functional theory calculations of electronic band structures and wave functions near the band gap, with semi-analytic approximations to include additional states farther away from the band gap. We show, in particular, the importance of all-electron reconstruction for recovering large momentum components of electronic wave functions, which, together with the inclusion of additional states, has a significant impact on direct detection rates, especially for heavy mediator models and at $mathcal{O}(10,text{eV})$ and higher energy depositions. Applying our framework to silicon and germanium (that have been established already as sensitive dark matter detectors), we find that our extended calculations can appreciably change the detection prospects. Our calculational framework is implemented in an open-source program $texttt{EXCEED-DM}$ (EXtended Calculation of Electronic Excitations for Direct detection of Dark Matter), to be released in an upcoming publication.
The unambiguous detection of Galactic dark matter annihilation would unravel one of the most outstanding puzzles in particle physics and cosmology. Recent observations have motivated models in which the annihilation rate is boosted by the Sommerfeld effect, a non-perturbative enhancement arising from a long range attractive force. Here we apply the Sommerfeld correction to Via Lactea II, a high resolution N-body simulation of a Milky-Way-size galaxy, to investigate the phase-space structure of the Galactic halo. We show that the annihilation luminosity from kinematically cold substructure can be enhanced by orders of magnitude relative to previous calculations, leading to the prediction of gamma-ray fluxes from up to hundreds of dark clumps that should be detectable by the Fermi satellite.
Sub-GeV mass dark matter particles whose collisions with nuclei would not deposit sufficient energy to be detected, could instead be revealed through their interaction with electrons. Analyses of data from direct detection experiments usually require assuming a local dark matter halo velocity distribution. In the halo-independent analysis method, properties of this distribution are instead inferred from direct dark matter detection data, which allows then to compare different data without making any assumption on the uncertain local dark halo. This method has so far been developed for and applied to dark matter scattering off nuclei. Here we demonstrate how this analysis can be applied to scattering off electrons.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
