Precision measurement of the beryllium-7 line with the Borexino detector

Borexino experiment was the first to directly investigate the sub-MeV region of the solar spec- trum in real-time. Its search for answers to some fundamental questions in the field of neutrino oscillations was accomplished with a precision measurement of the ⁷Be line at 5%; Borex- ino detected 46.0±1:5_stat^+1.6_-1.5 syst solar neutrino events/day/(100 tons) during Phase I of data taking. Further investigation of the signal led to the determination of day-night asymmetry that resulted in no significant variation; the detected asymmetry of 0.0010±0:012_stat0±0:007_syst is consistent with zero within the error. This note presents details of the precision measurement of the 7Be ν 's including the first release of the solar neutrino annual flux modulation.