scholarly journals New constraints on the mass of fermionic dark matter from dwarf spheroidal galaxies

2020 ◽  
Vol 501 (1) ◽  
pp. 1188-1201
Author(s):  
James Alvey ◽  
Nashwan Sabti ◽  
Victoria Tiki ◽  
Diego Blas ◽  
Kyrylo Bondarenko ◽  
...  

ABSTRACT Dwarf spheroidal galaxies are excellent systems to probe the nature of fermionic dark matter due to their high observed dark matter phase-space density. In this work, we review, revise, and improve upon previous phase-space considerations to obtain lower bounds on the mass of fermionic dark matter particles. The refinement in the results compared to previous works is realized particularly due to a significantly improved Jeans analysis of the galaxies. We discuss two methods to obtain phase-space bounds on the dark matter mass, one model-independent bound based on Pauli’s principle, and the other derived from an application of Liouville’s theorem. As benchmark examples for the latter case, we derive constraints for thermally decoupled particles and (non-)resonantly produced sterile neutrinos. Using the Pauli principle, we report a model-independent lower bound of $m \ge 0.18\, \mathrm{keV}$ at 68 per cent CL and $m \ge 0.13\, \mathrm{keV}$ at 95 per cent CL. For relativistically decoupled thermal relics, this bound is strengthened to $m \ge 0.59\, \mathrm{keV}$ at 68 per cent CL and $m \ge 0.41\, \mathrm{keV}$ at 95 per cent CL, while for non-resonantly produced sterile neutrinos the constraint is $m \ge 2.80\, \mathrm{keV}$ at 68 per cent CL and $m \ge 1.74\, \mathrm{keV}$ at 95 per cent CL. Finally, the phase-space bounds on resonantly produced sterile neutrinos are compared with complementary limits from X-ray, Lyman α, and big bang nucleosynthesis observations.

2018 ◽  
Vol 475 (4) ◽  
pp. 5385-5397 ◽  
Author(s):  
Chiara Di Paolo ◽  
Fabrizio Nesti ◽  
Francesco L Villante

2021 ◽  
Vol 2021 (10) ◽  
Author(s):  
Maíra Dutra ◽  
Vinícius Oliveira ◽  
C. A de S. Pires ◽  
Farinaldo S. Queiroz

Abstract We discuss a model where a mixed warm and hot keV neutrino dark matter rises naturally. We arrange active and sterile neutrinos in the same SU(3)L multiplet, with the lightest sterile neutrino being dark matter. The other two heavy sterile neutrinos, through their out-of-equilibrium decay, contribute both to the dilution of dark matter density and its population, after freeze-out. We show that this model features all ingredients to overcome the overproduction of keV neutrino dark matter, and explore the phenomenological implications for Big Bang Nucleosynthesis and the number of relativistic degrees of freedom.


2004 ◽  
Vol 13 (05) ◽  
pp. 819-830 ◽  
Author(s):  
M. D. POLLOCK

In the heterotic superstring theory, the decay constant of the QCD axion lies within the range 3×1016≲fa GeV ≲1018, the lower limit referring to the model-independent axion, while the upper limit is due to dimension-five, non-renormalizable effects first calculated by Cvetič. Consequently, the neutralino χ0, assumed to be a nearly pure B-ino, decays into the axino ã on the time scale obtained by Covi et al., [Formula: see text], which is ≲10-3 times the age of the Universe t0≈4×1017 s , but can only be made less than the time t≈1 s of the onset of Big-Bang nucleosynthesis by revising mχ0 to an unnaturally high level, mχ0≳500 TeV . Therefore, it is necessary to set the coefficient Ca YY =0, which is possible for the Kim–Shifman–Vainshtein–Zakharov invisible-axion model if the electric charge q c of the heavy-quark colour representation C vanishes. The neutralino does not then decay and can constitute some fraction of the dark matter of the Universe, depending upon the value of mχ0 (for a gaugino-dominated state, [Formula: see text] where [Formula: see text] is the SU(2) singlet slepton). The consequences of an ultra-light axion with fa≈1018 GeV are also discussed.


2018 ◽  
Vol 98 (4) ◽  
Author(s):  
Sebastian Bergström ◽  
Riccardo Catena ◽  
Andrea Chiappo ◽  
Jan Conrad ◽  
Björn Eurenius ◽  
...  

1997 ◽  
Vol 12 (21) ◽  
pp. 3669-3694 ◽  
Author(s):  
Nobuchika Okada ◽  
Osamu Yasuda

We analyze a scheme in which three active neutrinos and one sterile neutrino account for the solar, the atmospheric and the LSND neutrino anomalies in a model-independent way. It is shown that if the equivalent number, Nν, of the light neutrino species is less than 4, then the constraints from these anomalies, accelerator and reactor experiments and big bang nucleosynthesis force a general 4 × 4 mixing matrix to be effectively split into two 2 × 2 matrices. If these neutrinos are of the Majorana type, then negative results of neutrinoless double beta decay experiments imply that the total mass of neutrinos is not sufficient to account for all the hot dark matter components.


Sign in / Sign up

Export Citation Format

Share Document