About 30 Galactic supernova remnants (SNRs) are thought to be physically associated with molecular clouds (MCs). These systems are prime g-ray source candidates as the accelerated particles from shock fronts collide with the surrounding high-density
medium thus emitting gamma-rays through hadronic interactions. However only a handful of such interacting SNRs are detected at TeV energies. We report the current status of the High Energy Stereoscopic System (H.E.S.S.) observations towards these SNR-MC systems, with a particular emphasis on the latest results.
A new TeV source, HESS J1641-463, has been serendipitously discovered in the Galactic plane by the High Energy Stereoscopic System (H.E.S.S.) at a significance level of 8.6 standard deviations. The observations of HESS J1641-463 were performed betwee
n 2004 and 2011 and the source has a moderate flux level of 1.7% of the Crab Nebula flux at E > 1 TeV. HESS J1641-463 has a rather hard photon index of 1.99 +- 0.13_stat +- 0.20_sys. HESS J1641-463 is positionally coincident with the radio supernova remnant SNR G338.5+0.1, but no clear X-ray counterpart has been found in archival Chandra observations of the region. Different possible VHE production scenarios will be discussed in this contribution.
The differential cross-section for the process p(e,ep)eta has been measured at Q2 ~ 5.7 and 7.0 (GeV/c)2 for centre-of-mass energies from threshold to 1.8 GeV, encompassing the S11(1535) resonance, which dominates the channel. This is the highest mom
entum transfer measurement of this exclusive process to date. The helicity-conserving transition amplitude A_1/2, for the production of the S11(1535) resonance, is extracted from the data. Within the limited Q2 now measured, this quantity appears to begin scaling as 1/Q3 - a predicted, but not definitive, signal of the dominance of perturbative QCD, at Q2 ~ 5 (GeV/c)2.
