Description and performances of luminosity and background detectors at the upgraded e+e− collider

Abstract: Testing the new crab waist collision scheme at the e+e− Frascati accelerator complex requires a fast and accurate measurement of the absolute luminosity, as well as a full characterization of the background conditions. To fulfill these requirements, dedicated detectors have been built by the LUMI Collaboration and operated during the 2008 and 2009 runs, providing valuable inputs for the accelerator team. This article motivates their design, describes their installation in the modified interaction region and presents their performances. Another article in the same issue focuses on the results achieved using these detectors. [ABSTRACT FROM AUTHOR]