Speaker
Description
The Borexino experiment at the INFN Gran Sasso Laboratory is following a rich solar neutrino physics program. The Borexino most recent results are the precise measurements of the $^7$Be, pep and pp solar neutrino fluxes as well as the observation of season modulation of the $^7$Be solar neutrino rate. These results were derived from the so-called Borexino Phase-II data (i.e. data collected after some intense purification campaigns in 2010-2011) and were achieved thanks to advanced data analysis techniques that allowed to maximize the signal/noise ratio.
In this contribution, we present the data selection strategy of the Borexino solar neutrino analysis: we describe how the neutrino-like scintillation events are selected according to event-based cuts which eliminate most of the external and cosmogenic backgrounds. These cuts include the definition of a fiducial volume and time-correlation techniques with the muon veto events. Moreover, the spatial distribution of events and a $\beta^{+}/\beta^{-}$ pulse shape discrimination variable are used in a multivariate fit approach to additionally constrain the residual cosmogenic $^{11}$C and external backgrounds.
