Novel CSL bounds from the noise-induced radiation emission from atoms

TL;DR

This paper investigates radiation emission from atoms under the CSL collapse model, revealing nuclear contributions dominate at certain energies and setting new bounds on CSL parameters through underground experiments.

Contribution

It provides the first detailed analysis of atomic nuclei's role in CSL-induced radiation and establishes the strongest experimental bounds on CSL parameters for small correlation lengths.

Findings

Nuclear contribution to radiation grows quadratically with atomic number.

Electrons contribute linearly, but are less significant at high energies.

New bounds on CSL parameters surpass previous limits by over an order of magnitude.

Abstract

We study spontaneous radiation emission from matter, as predicted by the Continuous Spontaneous Localization (CSL) collapse model. We show that, in an appropriate range of energies of the emitted radiation, the largest contribution comes from the atomic nuclei. Specifically, we show that in the energy range $E\sim 10\,-\,10^{5}$ keV the contribution to the radiation emission from the atomic nuclei grows quadratically with the atomic number of the atom, overtaking the contribution from the electrons, which grows only linearly. This theoretical prediction is then compared with the data from a dedicated experiment performed at the extremely low background environment of the Gran Sasso underground National Laboratory, where the radiation emitted from a sample of Germanium was measured. As a result, we obtain the strongest bounds on the CSL parameters for $r_C\leq 10^{-6}$ m, improving the previous ones by more than an order of magnitude.