# Borexino and General Neutrino Interactions

## TL;DR

This paper uses Borexino solar neutrino data to set new constraints on all types of neutrino-electron interactions, including for tau neutrinos, extending the search for new physics to TeV scales.

## Contribution

It provides the first constraints on tau neutrino interactions and improves existing bounds for electron and muon neutrinos using Borexino data.

## Key findings

- New limits on all neutrino-electron interaction types.
- First constraints on tau neutrino interactions.
- Potential for future improvements with next-generation experiments.

## Abstract

We derive constraints on all possible general neutrino-electron interactions (scalar, vector, pseudoscalar, axialvector and tensor) using the recent real time Borexino event rate measurements of $pp$, $pep$ and $^{7}Be$ solar neutrinos. The limits improve several previous ones from TEXONO and CHARM-II for incoming electron and muon neutrinos, and are the first ones for the tau flavor. Future improvements by next-generation solar neutrino experiments are also studied. The limits extend the physics reach of solar neutrino measurements to TeV-scale physics. Finally, the different properties of the new interactions for Dirac and Majorana neutrinos are discussed.