Improved Limits on $n \rightarrow n'$ Transformation from the Spallation Neutron Source

• DOI: 10.48550/arxiv.2402.15981
• Publication Date: 2024-02-24
• Authors: Francisco M. Gonz...; Cary Rock; L. J. Broussard; Lisa DeBeer‐Schmitt; Matthew Frost; L. Heilbronn; Erik B. Iverson; Y. Kamyshkov; Michael Kline; D. Milstead; Devyn Powers; James E. Rogers; V. Santoro; Shaun Vavra
• Keywords: Spallation Neutron Source

Conversions between neutrons $n$ and Dark Matter candidate sterile $n'$ have been proposed as a mechanism for Baryon Number $\mathcal{B}$ violation. In the case that there is small mass difference $\Delta{m}$ states, oscillations can be induced by compensating with magnetic field. A search such neutron was performed at Spallation Neutron Source looking anomalous transmission through strongly absorbing cadmium wafer inside of $6.6$~T magnet. The approach described here saw no regenerated above background, which provides an improved limit - transformations range $0.1$~neV $1000$~neV.