Speaker
Description
We report some of the most recent results in studying different aspects of QCD with about 500 fb$-1$ of data collected by the BaBar experiment at the $e^+e^-$ $B$-factory PEP-II.
Among these, we present a high precision measurement of the mass difference between the $D^*(2010)^+$ and $D^+$ mesons using the decay chain $D^*(2010)^+ \to D^+ \pi^0$, with $D^+ \to K^- \pi^+ \pi^+$. This result is then combined with a previous BaBar measurement of $m(D^*(2010)^+) - m(D^0)$ to extract the mass difference between the charged and neutral $D$ mesons. We obtain results that are approximately seven times more precise than the present world averages.
We also report on the first evidence for a $B$-meson decay to four baryons, $B^0 \to p \bar{p} p \bar{p}$, which can help to shed light on the experimental discrepancy between the inclusive branching fraction of all $B$ meson decay modes with at least a couple of baryons in the final state, measured by ARGUS to be $(6.8 \pm 0.6)\%$ , and the sum of exclusive baryonic channels, Finally, we present a measurement of the spectral function for the $\tau^-\to K^-K_S\nu_{\tau}$ decay, which can be used to determine the hadronic contribution to the muon $g-2$ due to the vacuum polarization,
