Conversions between neutrons n and Dark Matter candidate sterile neutrons n′ have been proposed as a mechanism for Baryon Number B violation. In the case that there is a small mass difference Δm between the n and the n′ states, oscillations can be induced by compensating for Δm 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 Δm between 0.1~neV and 1000~neV.
@article{arxiv.2402.15981,
title = {Improved Limits on $n \rightarrow n'$ Transformation from the Spallation Neutron Source},
author = {Francisco M. Gonzalez and Cary Rock and Leah J. Broussard and Lisa DeBeer-Schmitt and Matthew J. Frost and Lawrence Heilbronn and Erik B. Iverson and Yuri Kamyshkov and Michael Kline and David Milstead and Devyn Powers and James Rogers and Valentina Santoro and Shaun Vavra},
journal= {arXiv preprint arXiv:2402.15981},
year = {2024}
}