No evidence yet for hadronic TeV gamma-ray emission from SNR RX J1713-3946

Recent TeV-scale γ-ray observations with the CANGAROO II telescope have led to the claim that the multi-band spectrum of RX J1713.7-3946 cannot be explained as the composite of a synchrotron and an inverse Compton component emitted by a population of relativistic electrons. It was argued that the spectrum of the high-energy emission is a good match to that predicted by pion decay, thus providing observational evidence that protons are accelerated in SNR to at least TeV energies. In this Letter we discuss the multi-band spectrum of RX J1713.7-3946 under the constraint that the GeV-scale emission observed from the closely associated EGRET source 3EG J1714-3857 is either associated with the SNR or an upper limit to the gammaray emission of the SNR. We find that the observed TeV-scale γ-ray emission of RX J1713.7-3946 cannot be explained by a pion decay component.