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Alleviating the $\bar B \to D τν$ and $\bar B \to D^* τν_τ$ puzzle in the MSSM

We show that Supersymmetric effects driven by penguin contributions to the $b \to c τν_τ$ transition are able to account simultaneously for a sizeable increase of both branching ratios of $\bar{B}\to D τ\barν_τ$ and $\bar{B} \to D^{*} τ\barν_τ$ with respect to the Standard Model predictions, thereby approaching their experimentally measured values. We emphasise that a light chargino and neutralino, with masses less than 300 GeV, in addition to a large stau/snueutrino mass and a large $\tanβ$, are essential for enhancing the effect of the lepton penguin $τν_τW^{\pm}$, which is responsible for the improved theoretical predictions with respect to current data.