Neutrino emission from dark matter annihilation/decay in light of cosmic $e^{\pm}$ and $\bar{p}$ data

Abstract

A self-consistent global fitting method based on the Markov Chain Monte Carlo technique to study the dark matter (DM) property associated with the cosmic ray electron/positron excesses was developed in our previous work. In this work we further improve the previous study to include the hadronic branching ratio of DM annihilation/decay. The PAMELA $\bar{p}/p$ data are employed to constrain the hadronic branching ratio. We find that the 95% ($2\sigma$) upper limits of the quark branching ratio allowed by the PAMELA $\bar{p}/p$ data is $\sim 0.032$ for DM annihilation and $\sim 0.044$ for DM decay respectively. This result shows that the DM coupling to pure leptons is indeed favored by the current data. Based on the global fitting results, we further study the neutrino emission from DM in the Galactic center. Our predicted neutrino flux is some smaller than previous works since the constraint from $\gamma$-rays is involved. However, it is still capable to be detected by the forth-coming neutrino detector such as IceCube. The improved points of the present study compared with previous works include: 1) the DM parameters, both the particle physical ones and astrophysical ones, are derived in a global fitting way, 2) constraints from various species of data sets, including $\gamma$-rays and antiprotons are included, and 3) the expectation of neutrino emission is fully self-consistent.