Title: Bounds on Velocity-dependent Dark Matter–Proton Scattering from Milky Way Satellite Abundance

Abstract

We use the latest measurements of the Milky Way satellite population from the Dark Energy Survey and Pan-STARRS1 to infer the most stringent astrophysical bound to date on velocity-dependent interactions between dark matter particles and protons. We model the momentum-transfer cross section as a power law of the relative particle velocity v with a free normalizing amplitude, σ_MT = σ₀vⁿ, to broadly capture the interactions arising within the nonrelativistic effective theory of dark matter–proton scattering. The scattering leads to a momentum and heat transfer between the baryon and dark matter fluids in the early universe, ultimately erasing structure on small physical scales and reducing the abundance of low-mass halos that host dwarf galaxies today. From the consistency of observations with the cold collisionless dark matter paradigm, using a new method that relies on the most robust predictions of the linear perturbation theory, we infer an upper limit on σ0 of 1.4 × 10^-23, 2.1 × 10^-19, and 1.0 × 10^-12 cm², for interaction models with n = 2, 4, and 6, respectively, for a dark matter particle mass of 10 MeV. These results improve observational limits on dark matter–proton scattering by orders of magnitude and thus provide an important guidemore » for viable sub-GeV dark matter candidates.« less

Authors:

Maamari, Karime  ^[1];

• Search DOE PAGES for author "Maamari, Karime"
• Search DOE PAGES for ORCID "0000-0002-7515-6208"

Gluscevic, Vera  ^[1];

• Search DOE PAGES for author "Gluscevic, Vera"
• Search DOE PAGES for ORCID "0000-0002-3589-8637"

Boddy, Kimberly K.  ^[2];

• Search DOE PAGES for author "Boddy, Kimberly K."
• Search DOE PAGES for ORCID "0000-0003-1928-4667"

Nadler, Ethan O.  ^[3];

• Search DOE PAGES for author "Nadler, Ethan O."
• Search DOE PAGES for ORCID "0000-0002-1182-3825"

Wechsler, Risa H.  ^[4]

• Search DOE PAGES for author "Wechsler, Risa H."
• Search DOE PAGES for ORCID "0000-0003-2229-011X"

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+ Show Author Affiliations

1. Univ. of Southern California, Los Angeles, CA (United States)
2. Univ. of Texas, Austin, TX (United States)
3. Stanford Univ., CA (United States)
4. Stanford Univ., CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States)

Publication Date:

Wed Feb 03 00:00:00 EST 2021

Research Org.:

SLAC National Accelerator Lab., Menlo Park, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1778002

Grant/Contract Number:  

AC02-76SF00515; PHY-2013951; NSF DGE-1656518

Resource Type:

Accepted Manuscript

Journal Name:

The Astrophysical Journal. Letters (Online)

Additional Journal Information:

Journal Name: The Astrophysical Journal. Letters (Online); Journal Volume: 907; Journal Issue: 2; Journal ID: ISSN 2041-8213

Publisher:

Institute of Physics (IOP)

Country of Publication:

United States

Language:

English

Subject:

79 ASTRONOMY AND ASTROPHYSICS; Dark matter (353); Milky Way dark matter halo (1049); Galaxy abundances (574)