Has AMS-02 observed two-component dark matter?

Author(s)

Profumo, Stefano ^[1] ; Queiroz, Farinaldo ^[2] ; Siqueira, Clarissa ^[2]

Affiliation

^[1] Univ Calif Santa Cruz, Santa Cruz Inst Particle Phys, Santa Cruz, CA 95064 - USA

^[2] Univ Fed Rio Grande do Norte, Int Inst Phys, Campus Univ, BR-59078970 Natal, RN - Brazil

• Document type: Journal article
• Source: JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS; v. 48, n. 1 JAN 2021.
• Web of Science Citations: 0

Abstract

There is convincing observational evidence for an increasing cosmic-ray positron-to-electron ratio at energies larger than similar to 10 GeV, at odds with expectations from secondary positron production. The most recent AMS-02 data exhibit an interesting spectral feature consisting of a bump at an energy around 300 GeV followed by a drop around similar to 800 GeV. A possible explanation for the most recent data is that the excess positron flux originates from decaying dark matter. Here, we show that models consisting of two dark matter particle species contributing equally to the global cosmological dark matter density provide good fits to the data. The favored models, with a best-fit with chi(2)/d.o.f similar to 2, consist of a first species weighing 750 GeV decaying with a lifetime tau(chi) similar to 10(26) s to tau lepton pairs (or to a pair of vector bosons subsequently decaying to a tau pair each), and a second species with a mass around 2.3 TeV decaying to mu lepton pairs. We provide a few possible concrete realizations for this scenario. (AU)

• FAPESP's process: 15/15897-1 - Cherenkov Telescope Array - CTA
• Grantee: Luiz Vitor de Souza Filho
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 16/01343-7 - ICTP South American Institute for Fundamental Research: a regional center for theoretical physics
• Grantee: Nathan Jacob Berkovits
• Support Opportunities: Special Projects