Relic density of wino-like dark matter in the MSSM

The relic density of TeV-scale wino-like neutralino dark matter in the MSSM is subject to potentially large corrections as a result of the Sommerfeld effect. A recently developed framework enables us to calculate the Sommerfeld-enhanced relic density in general MSSM scenarios, properly treating mixed states and multiple co-annihilating channels as well as including off-diagonal contributions. Using this framework, including on-shell one-loop mass splittings and running couplings and taking into account the latest experimental constraints, we perform a thorough study of the regions of parameter space surrounding the well known pure-wino scenario: namely the effect of sfermion masses being non-decoupled and of allowing non-negligible Higgsino or bino components in the lightest neutralino. We further perform an investigation into the effect of thermal corrections and show that these can safely be neglected. The results reveal a number of phenomenologically interesting but so far unexplored regions where the Sommerfeld effect is sizeable. We find, in particular, that the relic density can agree with experiment for dominantly wino neutralino dark matter with masses ranging from 1.7 to beyond 4 TeV. In light of these results the bounds from Indirect Detection on wino-like dark matter should be revisited.Comment: 49 pages, 15 figure

Hepatitis C virus outbreak in a haemodialysis unit: learning from failures

The investigation of an outbreak of hepatitis C virus in an Italian haemodialysis (HD) centre showed that three patients acquired infection with the same strain, affecting a chronically hepatitis C virus (HCV)-infected patient receiving HD in the same room and during the same shifts. Through our observational analysis many possible modes of transmission were identified, but none could be definitively identified as the route of HCV spread in this small cluster. This outbreak confirms that repeated opportunities for nosocomial HCV transmission may occur among HD patients due to several breaches in the standard precautions for bloodborne infections by healthcare staff