First data from the BaBar experiment at PEP II

The BaBar detector on the asymmetric e+e− PEP II accelerator facility at SLAC is a general purpose 4π detector which was built to study CP violation in the decays of B mesons. On May 26, 1999 the detector recorded its first collisions and started to accumulate data on and around the ϒ(4S) resonance. he author reviews the reasons for operating PEP II in an asymmetric mode. He then motivates the design of the BaBar detector and comments on its performance. Finally, some results collected in an energy scan around the ϒ(4S) resonance are presented. terial presented here is based on data collected within a few days of the start of operation and demonstrates that the detector components are working well and in most cases are at or near design performance. All results are preliminary.