Thermal relics in hidden sectors

Journal Article · Wed Oct 15 04:00:00 EDT 2008 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2008/10/043· OSTI ID:22156801

Feng, Jonathan L; Tu, Huitzu; Yu, Hai-Bo ^[1]

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1. Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States)

Dark matter may be hidden, with no standard model gauge interactions. At the same time, in WIMPless models (WIMP: weakly interacting massive particles) with hidden matter masses proportional to hidden gauge couplings squared, the hidden dark matter's thermal relic density may naturally be in the right range, preserving the key quantitative virtue of WIMPs. We consider this possibility in detail. We first determine model-independent constraints on hidden sectors from big bang nucleosynthesis and the cosmic microwave background. Contrary to conventional wisdom, large hidden sectors are easily accommodated. A flavour-free version of the standard model is allowed if the hidden sector is just 30% colder than the observable sector after reheating. Alternatively, if the hidden sector contains a one-generation version of the standard model with characteristic mass scale below 1 MeV, even identical reheating temperatures are allowed. We then analyse hidden sector freeze-out in detail for a concrete model, solving the Boltzmann equation numerically and explaining the results from both observable and hidden sector points of view. We find that WIMPless dark matter does indeed obtain the correct relic density for masses in the range keV{approx}

• OSTI ID: 22156801
• Journal Information: Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 10 Vol. 2008; ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
BOLTZMANN EQUATION
FLAVOR MODEL
FREEZING OUT
GAUGE INVARIANCE
LIMITING VALUES
MASS
MEV RANGE
NONLUMINOUS MATTER
NUCLEOSYNTHESIS
PARTICLES
RELICT RADIATION
STANDARD MODEL