Test of the 1.4 TeV DAMPE electron excess with preliminary H.E.S.S. measurement

Abstract

In November 2017, the DAMPE collaboration announced their first measurement of the electron spectrum between energies of 25 GeV and 4.6 TeV, including a narrow peak at ∼1.4 TeV with marginal significance. However, this feature is not observed in the larger statistic H.E.S.S. spectrum reported a few month earlier in the ICRC 2017. In this work, we perform a likelihood ratio method to test whether the DAMPE excess is compatible with the preliminary H.E.S.S. spectrum. By assuming the performance of the H.E.S.S. analysis is smooth with the electron energy, a 95% CL upper limit on a stable DAMPE-like signal is set at ∼17% of the DAMPE excess flux. The further investigation will rely on the formal publication of H.E.S.S. spectrum and higher statistic spectrum of DAMPE in the future.