Search for modulations of the solarBe7flux in the next-generation neutrino observatory LENA

A next-generation liquid-scintillator detector will be able to perform high-statistics measurements of the solar neutrino flux. In LENA, solar $^{7}\mathrm{Be}$ neutrinos are expected to cause $1.7\ifmmode\times\else\texttimes\fi{}{10}^{4}$ electron recoil events per day in a fiducial volume of 35 kilotons. Based on this signal, a search for periodic modulations on a subpercent level can be conducted, surpassing the sensitivity of current detectors by at least a factor of 20. The range of accessible periods reaches from several minutes, corresponding to modulations induced by helioseismic g-modes, to tens of years, allowing to study long-term changes in solar fusion rates.