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

Author:

Francisco M. Gonzalez, Cary Rock, Leah J. Broussard, Lisa DeBeer-Schmitt, Matthew J. Frost, Lawrence Heilbronn, Erik B. Iverson, Yuri Kamyshkov, Michael Kline, David Milstead, Devyn Powers, James Rogers, Valentina Santoro, Shaun Vavra

Keyword:

High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), Nuclear Experiment (nucl-ex)

journal:

date:

2024-02-25 00:00:00

Abstract

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 $\Delta{m}$ between the $n$ and the $n'$ states, oscillations can be induced by compensating for $\Delta{m}$ 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 $\Delta{m}$ between $0.1$~neV and $1000$~neV.

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