Title: Is Self-Interacting Dark Matter Undergoing Dark Fusion?

Abstract

Here, we suggest that two-to-two dark matter fusion may be the relaxation process that resolves the small-scale structure problems of the cold collisionless dark matter paradigm. In order for the fusion cross section to scale correctly across many decades of astrophysical masses from dwarf galaxies to galaxy clusters, we require the fractional binding energy released to be greater than vⁿ~(10^–(2–3))ⁿ, where n=1, 2 depends on local dark sector chemistry. The size of the dark-sector interaction cross sections must be σ~0.1–1 barn, moderately larger than for standard model deuteron fusion, indicating a dark nuclear scale Λ~O(100 MeV). Dark fusion firmly predicts constant σv below the characteristic velocities of galaxy clusters. Observations of the inner structure of galaxy groups with velocity dispersion of several hundred kilometers per second, of which a handful have been identified, could differentiate dark fusion from a dark photon model.

Authors:

McDermott, Samuel D.

Publication Date:

2018-06-01

Research Org.:

Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

Sponsoring Org.:

USDOE Office of Science (SC), High Energy Physics (HEP)

OSTI Identifier:

1439904

Alternate Identifier(s):

OSTI ID: 1410790

Report Number(s):

FERMILAB-PUB-17-483-A-T; arXiv:1711.00857
Journal ID: ISSN 0031-9007; PRLTAO; 221806

Grant/Contract Number:  

AC02-07CH11359

Resource Type:

Published Article

Journal Name:

Physical Review Letters

Additional Journal Information:

Journal Name: Physical Review Letters Journal Volume: 120 Journal Issue: 22; Journal ID: ISSN 0031-9007

Publisher:

American Physical Society (APS)

Country of Publication:

United States

Language:

English

Subject:

79 ASTRONOMY AND ASTROPHYSICS; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS