Improved Limits on $n \rightarrow n'$ Transformation from the Spallation Neutron Source
Francisco M. González, Cary Rock, L. J. Broussard, Lisa DeBeer‐Schmitt, Matthew Frost, L. Heilbronn, Erik B. Iverson, Yuri A. Kamyshkov, Kline, Michael, D. Milstead, Devyn Powers, James Edward Rogers, Valentina Santoro, Shaun Vavra · arXiv (Cornell University) · 2024
Conversions between neutrons $n$ and Dark Matter candidate sterile neutrons $n'$ have been proposed as a mechanism for Baryon Number $\mathcal{B}$ violation. In the case that there is a small mass difference $Δ{m}$ between the $n$ and the $n'$ states, oscillations can be induced by compensating for $Δ{m}$ with a magnetic field. A search for such neutron oscillations was performed at the Spallation Neutron Source by looking for anomalous neutron transmission through a strongly absorbing cadmium wafer inside of a $6.6$~T magnet. The approach described here saw no regenerated neutrons above background, which provides an improved limit for neutron - sterile neutrons transformations for a range of $Δ{m}$ between $0.1$~neV and $1000$~neV.