DAMPE squib? Significance of the 1.4 TeV DAMPE excess

Understand

We present a Bayesian and frequentist analysis of the DAMPE charged cosmic ray spectrum.

• The spectrum, by eye, contained a spectral break at about 1 TeV and a monochromatic excess at about 1.4 TeV.
• The break was supported by a Bayes factor of about $10^{10}$ and we argue that the statistical significance was resounding.
• We investigated whether we should attribute the excess to dark matter annihilation into electrons in a nearby subhalo.