A simple and natural interpretations of the DAMPE cosmic-ray electron/positron spectrum within two sigma deviations

TL;DR

This paper demonstrates that the DAMPE cosmic-ray electron/positron spectrum, including the spectral break and tentative peak, can be explained by simple models involving pulsars or dark matter, considering statistical fluctuations.

Contribution

It offers a natural interpretation of DAMPE data using minimal assumptions, incorporating statistical fluctuations, and introduces a $U(1)_D$ dark matter model with Breit-Wigner mechanism.

Findings

DAMPE data can be explained by pulsar and dark matter models with good fit quality.

Statistical fluctuations around the 1.4 TeV excess are consistent with observed deficits.

The proposed dark matter model can satisfy CMB constraints and explain the spectrum.

Abstract

The DArk Matter Particle Explorer (DAMPE) experiment has recently announced the first results for the measurement of total electron plus positron fluxes between 25 GeV and 4.6 TeV. A spectral break at about 0.9 TeV and a tentative peak excess around 1.4 TeV have been found. However, it is very difficult to reproduce both the peak signal and the smooth background including spectral break simultaneously. We point out that the numbers of events in the two energy ranges (bins) close to the 1.4 TeV excess have $1\sigma$ deficits. With the basic physics principles such as simplicity and naturalness, we consider the $-2\sigma$, $+2\sigma$, and $-1\sigma$ deviations due to statistical fluctuations for the 1229.3~GeV bin, 1411.4~GeV bin, and 1620.5~GeV bin. Interestingly, we show that all the DAMPE data can be explained consistently via both the continuous distributed pulsar and dark matter interpretations, which have $\chi^{2} \simeq 17.2 $ and $\chi^{2} \simeq 13.9$ (for all the 38 points in DAMPE electron/positron spectrum with 3 of them revised), respectively. These results are different from the previous analyses by neglecting the 1.4 TeV excess. At the same time, we do a similar global fitting on the newly released CALET lepton data, which could also be interpreted by such configurations. Moreover, we present a $U(1)_D$ dark matter model with Breit-Wigner mechanism, which can provide the proper dark matter annihilation cross section and escape the CMB constraint. Furthermore, we suggest a few ways to test our proposal.