New high-sensitivity searches for neutrons converting into antineutrons and/or sterile neutrons at the HIBEAM/NNBAR experiment at the European Spallation Source



Addazi, A, Anderson, K, Ansell, S, Babu, KS, Barrow, JL, Baxter, DV, Bentley, PM, Berezhiani, Z, Bevilacqua, R, Biondi, R
et al (show 104 more authors) (2021) New high-sensitivity searches for neutrons converting into antineutrons and/or sterile neutrons at the HIBEAM/NNBAR experiment at the European Spallation Source. JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS, 48 (7). 070501-070501.

Access the full-text of this item by clicking on the Open Access link.
[img] Text
2006.04907v1.pdf - Submitted version

Download (7MB) | Preview

Abstract

The violation of Baryon Number, $\mathcal{B}$, is an essential ingredient for the preferential creation of matter over antimatter needed to account for the observed baryon asymmetry in the universe. However, such a process has yet to be experimentally observed. The HIBEAM/NNBAR %experiment program is a proposed two-stage experiment at the European Spallation Source (ESS) to search for baryon number violation. The program will include high-sensitivity searches for processes that violate baryon number by one or two units: free neutron-antineutron oscillation ($n\rightarrow \bar{n}$) via mixing, neutron-antineutron oscillation via regeneration from a sterile neutron state ($n\rightarrow [n',\bar{n}'] \rightarrow \bar{n}$), and neutron disappearance ($n\rightarrow n'$); the effective $\Delta \mathcal{B}=0$ process of neutron regeneration ($n\rightarrow [n',\bar{n}'] \rightarrow n$) is also possible. The program can be used to discover and characterise mixing in the neutron, antineutron, and sterile neutron sectors. The experiment addresses topical open questions such as the origins of baryogenesis, the nature of dark matter, and is sensitive to scales of new physics substantially in excess of those available at colliders. A goal of the program is to open a discovery window to neutron conversion probabilities (sensitivities) by up to three orders of magnitude compared with previous searches. The opportunity to make such a leap in sensitivity tests should not be squandered. The experiment pulls together a diverse international team of physicists from the particle (collider and low energy) and nuclear physics communities, while also including specialists in neutronics and magnetics.

Item Type: Article
Uncontrolled Keywords: baryon number violation, feebly interacting particles, European Spallation Source, baryogenesis
Divisions: Faculty of Science and Engineering > School of Physical Sciences
Depositing User: Symplectic Admin
Date Deposited: 27 Jul 2022 14:30
Last Modified: 23 Feb 2023 02:49
DOI: 10.1088/1361-6471/abf429
Open Access URL: https://iopscience.iop.org/article/10.1088/1361-64...
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3159678