Search for New Physics with Gluonic Penguin $B$ Decays

Charmless $B$-meson decays such as $B\to \eta^\prime K$ and $B\to \phi K$ are dominated by transitions into a $s$-quark and a gluon via internal $W$-quark loops. In these loops new particles and forces as e.g. predicted by supersymmetric models can contribute virtually. This provides an opportunity to detect such New Physics as deviation of $CP$ asymmetries from Standard Model expectations and with negligible or small hadronic uncertainties. The BaBar collaboration has now accumulated more than 350 million $\bar{B}B$ events at the $\Upsilon(4S)$ resonance. To overcome the rareness of these charmless $B$ decay final states we have reconstructed many sub-decay modes and additional similar penguin decays. We present the new $CP$ measurements in the $\eta^\prime K$ and $\phi (K^+K^-)K$ final states. With time-dependent $B$-decay Dalitz plot analyses we expand the spectrum of penguin decays.