scholarly journals Confronting the Fermi line with LHC data: An effective theory of dark matter interaction with photons

2014 ◽  
Vol 89 (5) ◽  
Author(s):  
Andy Nelson ◽  
Linda M. Carpenter ◽  
Randel Cotta ◽  
Adam Johnstone ◽  
Daniel Whiteson
Keyword(s):  
Dark Matter ◽  
Effective Theory ◽  
Matter Interaction ◽  
Fermi Line

scholarly journals Exothermic dark matter for XENON1T excess

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Hyun Min Lee
Keyword(s):  
Dark Matter ◽  
Mass Difference ◽  
Mass Splitting ◽  
Effective Theory ◽  
Recoil Energy ◽  
Detector Resolution ◽  
Atomic Excitation ◽  
Microscopic Models ◽  
Electron Recoil ◽  
Two Component

Abstract Motivated by the recent excess in the electron recoil from XENON1T experiment, we consider the possibility of exothermic dark matter, which is composed of two states with mass splitting. The heavier state down-scatters off the electron into the lighter state, making an appropriate recoil energy required for the Xenon excess even for the standard Maxwellian velocity distribution of dark matter. Accordingly, we determine the mass difference between two component states of dark matter to the peak electron recoil energy at about 2.5 keV up to the detector resolution, accounting for the recoil events over ER = 2 − 3 keV, which are most significant. We include the effects of the phase-space enhancement and the atomic excitation factor to calculate the required scattering cross section for the Xenon excess. We discuss the implications of dark matter interactions in the effective theory for exothermic dark matter and a massive Z′ mediator and provide microscopic models realizing the required dark matter and electron couplings to Z′.

scholarly journals A combined analysis of PandaX, LUX, and XENON1T experiments within the framework of dark matter effective theory

2017 ◽  
Vol 2017 (11) ◽  
Author(s):  
Zuowei Liu ◽  
Yushan Su ◽  
Yue-Lin Sming Tsai ◽  
Bingrong Yu ◽  
Qiang Yuan
Keyword(s):  
Dark Matter ◽  
Effective Theory ◽  
Combined Analysis

scholarly journals ETHOS – an effective theory of structure formation: formation of the first haloes and their stars

2019 ◽  
Vol 485 (4) ◽  
pp. 5474-5489 ◽  
Author(s):  
Mark R Lovell ◽  
Jesús Zavala ◽  
Mark Vogelsberger
Keyword(s):  
Dark Matter ◽  
Power Spectrum ◽  
Galaxy Formation ◽  
Cold Dark Matter ◽  
Dwarf Galaxy ◽  
Mass Scale ◽  
Effective Theory ◽  
Matter Power Spectrum ◽  
Hydrodynamical Simulations ◽  
Stellar Masses

Abstract A cut-off in the linear matter power spectrum at dwarf galaxy scales has been shown to affect the abundance, formation mechanism and age of dwarf haloes, and their galaxies at high and low redshifts. We use hydrodynamical simulations of galaxy formation within the ETHOS framework in a benchmark model that has such a cut-off and that has been shown to be an alternative to the cold dark matter (CDM) model that alleviates its dwarf-scale challenges. We show how galaxies in this model form differently to CDM, on a halo-by-halo basis, at redshifts z ≥ 6. We show that when CDM haloes with masses around the ETHOS half-mode mass scale are resimulated with the ETHOS matter power spectrum, they form with 50 per cent less mass than their CDM counterparts due to their later formation times, yet they retain more of their gas reservoir due to the different behaviour of gas and dark matter during the monolithic collapse of the first haloes in models with a galactic-scale cut-off. As a result, galaxies in ETHOS haloes near the cut-off scale grow rapidly between z = 10 and 6 and by z = 6 end up having very similar stellar masses, higher gas fractions and higher star formation rates relative to their CDM counterparts. We highlight these differences by making predictions for how the number of galaxies with old stellar populations is suppressed in ETHOS for both z = 6 galaxies and for gas-poor Local Group fossil galaxies. Interestingly, we find an age gradient in ETHOS between galaxies that form in high- and low-density environments.

NEW LIMITS ON THE WIMP COLD DARK MATTER INTERACTION CROSS SECTION FROM THE UK EXPERIMENT

COSMO-97 ◽  
1998 ◽  
Author(s):  
T. Ali ◽  
T. J. Sumner ◽  
J. J. Quenby ◽  
A. Bewick ◽  
N. J. T. Smith ◽  
...  
Keyword(s):  
Dark Matter ◽  
Cross Section ◽  
Cold Dark Matter ◽  
Interaction Cross Section ◽  
Matter Interaction ◽  
The Uk

scholarly journals Viscosity in cosmic fluids

2020 ◽  
Vol 80 (8) ◽  
Author(s):  
Pravin Kumar Natwariya ◽  
Jitesh R. Bhatt ◽  
Arun Kumar Pandey
Keyword(s):  
Dark Matter ◽  
Effective Viscosity ◽  
Large Scale ◽  
Significant Contribution ◽  
Viscosity Coefficient ◽  
Effective Theory ◽  
Viscous Effect ◽  
Dissipative Effects ◽  
Large Scale Structure Formation

Abstract The effective theory of large-scale structure formation based on $$\Lambda $$ΛCDM paradigm predicts finite dissipative effects in the resulting fluid equations. In this work, we study how viscous effect that could arise if one includes self-interaction among the dark-matter particles combines with the effective theory. It is shown that these two possible sources of dissipation can operate together in a cosmic fluid and the interplay between them can play an important role in determining dynamics of the cosmic fluid. In particular, we demonstrate that the viscosity coefficient due to self-interaction is added inversely with the viscosity calculated using effective theory of $$\Lambda $$ΛCDM model. Thus the larger viscosity has less significant contribution in the effective viscosity. Using the known bounds on $$\sigma /m$$σ/m for self-interacting darkmatter, where $$\sigma $$σ and m are the cross-section and mass of the dark-matter particles respectively, we discuss role of the effective viscosity in various cosmological scenarios.

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