PREPRINT
A26CA81E-5E57-44F8-8CEA-CB15D89DFF51

# Neutrino forces in neutrino backgrounds

Mitrajyoti Ghosh, Yuval Grossman, Walter Tangarife, Xun-Jie Xu, Bingrong Yu

Submitted on 15 September 2022

## Abstract

The Standard Model predicts a long-range force between fermions due to the exchange of a pair of neutrinos. However, this quantum force, proportional to ${G}_{F}^{2}/{r}^{5}$ in the massless neutrino limit, is feeble and has not yet been observed in experiments. In this paper, we compute this force, including the background effect caused by cosmic, reactor, and solar neutrinos. We find that the neutrino force can be significantly stronger in the presence of neutrino backgrounds. Remarkably, reactor neutrino background can strengthen the neutrino force by more than 20 orders of magnitude compared with the one in vacuum. We discuss the experimental prospects of detecting the neutrino force in neutrino backgrounds and find that the effect is close to the available sensitivity of the current fifth force experiments. The results are encouraging and a detailed experimental study is called for to check if the effect can be probed.

## Preprint

Comment: 30 pages, 4 figures, 4 tables; comments are welcome

Subjects: High Energy Physics - Phenomenology; Astrophysics - Cosmology and Nongalactic Astrophysics; Astrophysics - High Energy Astrophysical Phenomena; High Energy Physics - Experiment