Luminosity and background measurements at the e+e−DAΦNEDAΦNE collider upgraded with the crab waist scheme

The crab waist collision scheme has been successfully tested at the e+e− Frascati collider during the 2008–2009 runs: the gain in luminosity is consistent with the predictions while the background remains sustainable. Among the various inputs used by the DAΦNEDAΦNE accelerator team to steer this new machine and improve its performances, key online information, absolute luminosity and background level measurements, has been provided by the LUMI detectors: a Bhabha calorimeter and two gamma bremsstrahlung proportional counters. This paper focuses on the results achieved with this experimental setup, described in details in another article.