HELENA - a beauty factory in Hamburg

A high-luminosity asymmetric energy e+e- collider, operated at the Υ (4S) energy, provide the best opportunity to study CP violation as a means of testing the consistency of the Standard Model. If the phenomenon of CP violation is explained by the Standard Model through the non-zero angles and phase of the Cabibbo-Kobayashi-Maskawa matrix, then there are precise relations between the CKM parameters and the various measurable CP violating asymmetries in B meson decay. Should these consistency relations fail, the origin of CP violation must lie outside of the Standard Model framework. The measurement would then lead to the first observation of physics beyond the Standard Model. The B Factory will also carry out a varied, high quality program of studies of other aspects of the physics of b quarks, as well as high precision measurements in τ and charm physics. The peak luminosity of 3.1033 cm-2s-1 necessary for such a physics program can be achieved with a double ring e+e- collider that fits into the PETRA tunnel at DESY, and that can be constructed using presently existing techniques. We describe the design of a universal magnetic detector that is optimized for the observation of CP violation, but also allows for a wide additional physics program. The combination of collider and detector can be built within 4 years for an estimated cost of 175 MDM and 104 MDM, respectively. (orig.)