AMS-02 fits dark matter

Abstract

In this work we perform a comprehensive statistical analysis of the AMS-02 electron, positron fluxes and the antiproton-to-proton ratio in the context of a simplified dark matter model. We include known, standard astrophysical sources and a dark matter component in the cosmic ray injection spectra. To predict the AMS-02 observables we use propagation parameters extracted from observed fluxes of heavier nuclei and the low energy part of the AMS-02 data. We assume that the dark matter particle is a Majorana fermion coupling to third generation fermions via a spin-0 mediator, and annihilating to multiple channels at once. The simultaneous presence of various annihilation channels provides the dark matter model with additional flexibility, and this enables us to simultaneously fit all cosmic ray spectra using a simple particle physics model and coherent astrophysical assumptions. Our results indicate that AMS-02 observations are not only consistent with the dark matter hypothesis within the uncertainties, but adding a dark matter contribution improves the fit to the data. Assuming, however, that dark matter is solely responsible for this improvement of the fit, it is difficult to evade the latest CMB limits in this model.

Revisiting simplified dark matter models in terms of AMS-02 and Fermi-LAT

“…As mentioned above, for each set of dark matter mass and mediator mass, we first generate the antiproton spectrum dN p/dE, and calculate the dark matter annihilation cross section. These dark matter model dependent variables are then passed into the public code Galprop v54 [43][44][45][46][47] to ensure that near Earth cosmic ray fluxes from dark matter annihilation and background are obtained in a consistent way [48]. The obtained cosmic ray fluxes, together with the experimental data points, are put into a composite likelihood function, defined as…”

Simplified dark matter models in the light of AMS-02 antiproton data

“…A self-consistent way to take into account the dark matter source is to propagate the antiproton spectrum induced by dark matter annihilation through the Galaxy and calculate the antiproton flux under the exact same set of the above astrophysical parameters. This procedure ensures a consistent astrophysical treatment of cosmic rays from the standard astrophysical source and dark matter [12].…”

Dark matter properties implied by gamma ray interstellar emission models

“…In this section, we describe the simplified dark matter model we use in our analysis. Majorana fermions recently emerged as the most plausible dark matter particle candidates in the simplified model context [80,[122][123][124][127][128][129][130][131]. Motivated by this, we assume that dark matter consists of a single Majorana fermion, which we denote by χ. Additionally, motivated by the listed literature and the Higgs portal, we assume that the interaction between the dark matter particle and standard fermions is mediated by a scalar particle S [132,133].…”

“…To make minimal and general theoretical assumptions we use the simplified model framework assuming that dark matter is a Majorana fermion coupling to standard fermions via a scalar mediator. This particular simplified model has unsuppressed indirect, and suppressed direct and collider detection rates, and emerged as the most plausible one when compared with a wide range of data [123][124][125]. To show the role of the IEM assumptions in constraining dark matter properties, we infer the properties JCAP02(2017)037 of these dark matter particles using the multiple Fermi data sets categorized by different choices of IEMs and spectral models.…”