Neutron EDM
Lead Research Organisation:
University of Sussex
Department Name: Sch of Mathematical & Physical Sciences
Abstract
Neutrons are an elemental part of the nucleus of the atom. Although electrically neutral overall, neutrons are made up of charged particles. The neutron electric dipole moment (nEDM) is a measure of the distribution of positive and negative charge inside the neutron - just as a magnet has north and south poles, so a neutron with an EDM would have one end slightly negative, and the other slightly positive. However, this can only happen if certain symmetries in the laws of physics are slightly broken - by exactly the same mechanisms that were responsible for the dominance of matter over anti-matter in the Universe at the time of the Big Bang. These mechanisms are not understood, but by measuring (and putting limits upon) the nEDM, we put extremely tight constraints upon new models of physics that attempt to explain the origin of all of the matter in the Universe.
Our group currently holds the world's best limit in the precision of measurement of this fundamental quantity. The proposed work will improve the sensitivity by a factor of two in the first instance, and later on by much more - perhaps approaching an order of magnitude.
Our group currently holds the world's best limit in the precision of measurement of this fundamental quantity. The proposed work will improve the sensitivity by a factor of two in the first instance, and later on by much more - perhaps approaching an order of magnitude.
Planned Impact
This project has a long and venerable history, and in its orignal incarnation was directly linked to the development of the magnetic resonance techniques underlying atomic clocks and MRI scanners. Although the future is hard to anticipate, as far as we can foresee at this stage the primary non-academic impact of this work will be in outreach: audiences are fascinated by the science underlying the origins of the Universe, and at Sussex we have a well established outreach programme of which the EDM work is a key facet.
Organisations
- University of Sussex (Lead Research Organisation)
- Jagiellonian University (Collaboration)
- ETH Zurich (Collaboration)
- Paul Scherrer Institute (Collaboration)
- Polish Academy of Sciences (Collaboration)
- University of Fribourg (Collaboration)
- Johannes Gutenberg University of Mainz (Collaboration)
- National Center for Scientific Research (Centre National de la Recherche Scientifique CNRS) (Collaboration)
- UZ Leuven, Belgium (Collaboration)
- University of Bern (Collaboration)
- Laboratoire de Physique (Collaboration)
- University of Kentucky (Collaboration)
- Physikalisch-Technische Bundesanstalt (Collaboration)
Publications
Abel C
(2022)
Mapping of the magnetic field to correct systematic effects in a neutron electric dipole moment experiment
in Physical Review A
Abel C
(2019)
The n2EDM experiment at the Paul Scherrer Institute
in EPJ Web of Conferences
Abel C
(2019)
PicoTesla absolute field readings with a hybrid 3He/87Rb magnetometer
in The European Physical Journal D
Abel C
(2021)
A search for neutron to mirror-neutron oscillations using the nEDM apparatus at PSI
in Physics Letters B
Abel C
(2018)
The n2EDM experiment at the Paul Scherrer Institute
Abel C
(2020)
A search for neutron to mirror-neutron oscillations
Abel C
(2020)
Measurement of the Permanent Electric Dipole Moment of the Neutron.
in Physical review letters
Abel C
(2020)
Optically pumped Cs magnetometers enabling a high-sensitivity search for the neutron electric dipole moment
in Physical Review A
| Description | This grant funds development work towards one of the most precise and exquisite measurements that it's possible to make in physics: the search for the so-called Electric Dipole Moment (EDM) of the neutron. This is a tiny distortion of the structure of the neutron (a subatomic particle), perhaps a billion times smaller than anything that LHC is capable of detecting. It is critically important for helping us to understand the origin of all of the matter in the Universe - including all of us, and the stars and planets - since the size of this subatomic distortion is intimately related to the question of the difference between matter and antimatter, which led to our Universe being matter-dominated. We use a sort of atomic clock to study the behaviour of neutrons in strong electric fields, which allow us ever increasing sensitivity in the measurement. Our latest result (Feb 2020) has a factor 5 reduction in systematic errors, and an overall 40% reduction in the world's tightest limit on the magnitude of the neutron EDM. |
| Exploitation Route | Findings will be of immense importance to theorists trying to understand the origins of matter in the Universe. |
| Sectors | Education |
| URL | https://www.psi.ch/nedm/publications |
| Description | This work is regularly used for outreach purposes, to inspire the next generation of (potential) physicists. |
| First Year Of Impact | 2014 |
| Sector | Education |
| Impact Types | Cultural |
| Description | PSI EDM |
| Organisation | ETH Zurich |
| Department | Department of Chemistry and Applied Biosciences |
| Country | Switzerland |
| Sector | Academic/University |
| PI Contribution | We are taking on responsibility for coordination of key parts of the neutron EDM project, in particular helium magnetometry, Ramsey cell design, and systematics analysis. (We also built, many years ago, the original apparatus on which the current project is based...) |
| Collaborator Contribution | Although the collaboration is based at PSI, it encompasses many partners from around Europe. PSI is providing the source, much of the equipment, substantial manpower. (My estimate of 5 M CHF is probably wildly inaccurate.) The collaboration has existed for quite some years but we only joined it in 2014. |
| Impact | 10.1103/PhysRevD.92.092003 10.1103/PhysRevLett.115.162502 10.1103/PhysRevD.92.052008 10.1140/epjd/e2015-60207-4 10.1016/j.physletb.2014.10.046 Papers are starting to emerge... the first since I joined has been submitted for publication. |
| Start Year | 2014 |
| Description | PSI EDM |
| Organisation | Jagiellonian University |
| Country | Poland |
| Sector | Academic/University |
| PI Contribution | We are taking on responsibility for coordination of key parts of the neutron EDM project, in particular helium magnetometry, Ramsey cell design, and systematics analysis. (We also built, many years ago, the original apparatus on which the current project is based...) |
| Collaborator Contribution | Although the collaboration is based at PSI, it encompasses many partners from around Europe. PSI is providing the source, much of the equipment, substantial manpower. (My estimate of 5 M CHF is probably wildly inaccurate.) The collaboration has existed for quite some years but we only joined it in 2014. |
| Impact | 10.1103/PhysRevD.92.092003 10.1103/PhysRevLett.115.162502 10.1103/PhysRevD.92.052008 10.1140/epjd/e2015-60207-4 10.1016/j.physletb.2014.10.046 Papers are starting to emerge... the first since I joined has been submitted for publication. |
| Start Year | 2014 |
| Description | PSI EDM |
| Organisation | Johannes Gutenberg University of Mainz |
| Country | Germany |
| Sector | Academic/University |
| PI Contribution | We are taking on responsibility for coordination of key parts of the neutron EDM project, in particular helium magnetometry, Ramsey cell design, and systematics analysis. (We also built, many years ago, the original apparatus on which the current project is based...) |
| Collaborator Contribution | Although the collaboration is based at PSI, it encompasses many partners from around Europe. PSI is providing the source, much of the equipment, substantial manpower. (My estimate of 5 M CHF is probably wildly inaccurate.) The collaboration has existed for quite some years but we only joined it in 2014. |
| Impact | 10.1103/PhysRevD.92.092003 10.1103/PhysRevLett.115.162502 10.1103/PhysRevD.92.052008 10.1140/epjd/e2015-60207-4 10.1016/j.physletb.2014.10.046 Papers are starting to emerge... the first since I joined has been submitted for publication. |
| Start Year | 2014 |
| Description | PSI EDM |
| Organisation | Johannes Gutenberg University of Mainz |
| Country | Germany |
| Sector | Academic/University |
| PI Contribution | We are taking on responsibility for coordination of key parts of the neutron EDM project, in particular helium magnetometry, Ramsey cell design, and systematics analysis. (We also built, many years ago, the original apparatus on which the current project is based...) |
| Collaborator Contribution | Although the collaboration is based at PSI, it encompasses many partners from around Europe. PSI is providing the source, much of the equipment, substantial manpower. (My estimate of 5 M CHF is probably wildly inaccurate.) The collaboration has existed for quite some years but we only joined it in 2014. |
| Impact | 10.1103/PhysRevD.92.092003 10.1103/PhysRevLett.115.162502 10.1103/PhysRevD.92.052008 10.1140/epjd/e2015-60207-4 10.1016/j.physletb.2014.10.046 Papers are starting to emerge... the first since I joined has been submitted for publication. |
| Start Year | 2014 |
| Description | PSI EDM |
| Organisation | Laboratoire de Physique |
| Country | France |
| Sector | Academic/University |
| PI Contribution | We are taking on responsibility for coordination of key parts of the neutron EDM project, in particular helium magnetometry, Ramsey cell design, and systematics analysis. (We also built, many years ago, the original apparatus on which the current project is based...) |
| Collaborator Contribution | Although the collaboration is based at PSI, it encompasses many partners from around Europe. PSI is providing the source, much of the equipment, substantial manpower. (My estimate of 5 M CHF is probably wildly inaccurate.) The collaboration has existed for quite some years but we only joined it in 2014. |
| Impact | 10.1103/PhysRevD.92.092003 10.1103/PhysRevLett.115.162502 10.1103/PhysRevD.92.052008 10.1140/epjd/e2015-60207-4 10.1016/j.physletb.2014.10.046 Papers are starting to emerge... the first since I joined has been submitted for publication. |
| Start Year | 2014 |
| Description | PSI EDM |
| Organisation | Laboratoire de Physique |
| Country | France |
| Sector | Academic/University |
| PI Contribution | We are taking on responsibility for coordination of key parts of the neutron EDM project, in particular helium magnetometry, Ramsey cell design, and systematics analysis. (We also built, many years ago, the original apparatus on which the current project is based...) |
| Collaborator Contribution | Although the collaboration is based at PSI, it encompasses many partners from around Europe. PSI is providing the source, much of the equipment, substantial manpower. (My estimate of 5 M CHF is probably wildly inaccurate.) The collaboration has existed for quite some years but we only joined it in 2014. |
| Impact | 10.1103/PhysRevD.92.092003 10.1103/PhysRevLett.115.162502 10.1103/PhysRevD.92.052008 10.1140/epjd/e2015-60207-4 10.1016/j.physletb.2014.10.046 Papers are starting to emerge... the first since I joined has been submitted for publication. |
| Start Year | 2014 |
| Description | PSI EDM |
| Organisation | National Center for Scientific Research (Centre National de la Recherche Scientifique CNRS) |
| Department | Centre for Nuclear Sciences and Material Sciences (CSNSM) |
| Country | France |
| Sector | Public |
| PI Contribution | We are taking on responsibility for coordination of key parts of the neutron EDM project, in particular helium magnetometry, Ramsey cell design, and systematics analysis. (We also built, many years ago, the original apparatus on which the current project is based...) |
| Collaborator Contribution | Although the collaboration is based at PSI, it encompasses many partners from around Europe. PSI is providing the source, much of the equipment, substantial manpower. (My estimate of 5 M CHF is probably wildly inaccurate.) The collaboration has existed for quite some years but we only joined it in 2014. |
| Impact | 10.1103/PhysRevD.92.092003 10.1103/PhysRevLett.115.162502 10.1103/PhysRevD.92.052008 10.1140/epjd/e2015-60207-4 10.1016/j.physletb.2014.10.046 Papers are starting to emerge... the first since I joined has been submitted for publication. |
| Start Year | 2014 |
| Description | PSI EDM |
| Organisation | Paul Scherrer Institute |
| Country | Switzerland |
| Sector | Academic/University |
| PI Contribution | We are taking on responsibility for coordination of key parts of the neutron EDM project, in particular helium magnetometry, Ramsey cell design, and systematics analysis. (We also built, many years ago, the original apparatus on which the current project is based...) |
| Collaborator Contribution | Although the collaboration is based at PSI, it encompasses many partners from around Europe. PSI is providing the source, much of the equipment, substantial manpower. (My estimate of 5 M CHF is probably wildly inaccurate.) The collaboration has existed for quite some years but we only joined it in 2014. |
| Impact | 10.1103/PhysRevD.92.092003 10.1103/PhysRevLett.115.162502 10.1103/PhysRevD.92.052008 10.1140/epjd/e2015-60207-4 10.1016/j.physletb.2014.10.046 Papers are starting to emerge... the first since I joined has been submitted for publication. |
| Start Year | 2014 |
| Description | PSI EDM |
| Organisation | Physikalisch-Technische Bundesanstalt |
| Country | Germany |
| Sector | Academic/University |
| PI Contribution | We are taking on responsibility for coordination of key parts of the neutron EDM project, in particular helium magnetometry, Ramsey cell design, and systematics analysis. (We also built, many years ago, the original apparatus on which the current project is based...) |
| Collaborator Contribution | Although the collaboration is based at PSI, it encompasses many partners from around Europe. PSI is providing the source, much of the equipment, substantial manpower. (My estimate of 5 M CHF is probably wildly inaccurate.) The collaboration has existed for quite some years but we only joined it in 2014. |
| Impact | 10.1103/PhysRevD.92.092003 10.1103/PhysRevLett.115.162502 10.1103/PhysRevD.92.052008 10.1140/epjd/e2015-60207-4 10.1016/j.physletb.2014.10.046 Papers are starting to emerge... the first since I joined has been submitted for publication. |
| Start Year | 2014 |
| Description | PSI EDM |
| Organisation | Polish Academy of Sciences |
| Department | Henryk Niewodniczanski Institute of Nuclear Physics Pan |
| Country | Poland |
| Sector | Academic/University |
| PI Contribution | We are taking on responsibility for coordination of key parts of the neutron EDM project, in particular helium magnetometry, Ramsey cell design, and systematics analysis. (We also built, many years ago, the original apparatus on which the current project is based...) |
| Collaborator Contribution | Although the collaboration is based at PSI, it encompasses many partners from around Europe. PSI is providing the source, much of the equipment, substantial manpower. (My estimate of 5 M CHF is probably wildly inaccurate.) The collaboration has existed for quite some years but we only joined it in 2014. |
| Impact | 10.1103/PhysRevD.92.092003 10.1103/PhysRevLett.115.162502 10.1103/PhysRevD.92.052008 10.1140/epjd/e2015-60207-4 10.1016/j.physletb.2014.10.046 Papers are starting to emerge... the first since I joined has been submitted for publication. |
| Start Year | 2014 |
| Description | PSI EDM |
| Organisation | UZ Leuven, Belgium |
| Department | Orthopedics |
| Country | Belgium |
| Sector | Hospitals |
| PI Contribution | We are taking on responsibility for coordination of key parts of the neutron EDM project, in particular helium magnetometry, Ramsey cell design, and systematics analysis. (We also built, many years ago, the original apparatus on which the current project is based...) |
| Collaborator Contribution | Although the collaboration is based at PSI, it encompasses many partners from around Europe. PSI is providing the source, much of the equipment, substantial manpower. (My estimate of 5 M CHF is probably wildly inaccurate.) The collaboration has existed for quite some years but we only joined it in 2014. |
| Impact | 10.1103/PhysRevD.92.092003 10.1103/PhysRevLett.115.162502 10.1103/PhysRevD.92.052008 10.1140/epjd/e2015-60207-4 10.1016/j.physletb.2014.10.046 Papers are starting to emerge... the first since I joined has been submitted for publication. |
| Start Year | 2014 |
| Description | PSI EDM |
| Organisation | University of Bern |
| Country | Switzerland |
| Sector | Academic/University |
| PI Contribution | We are taking on responsibility for coordination of key parts of the neutron EDM project, in particular helium magnetometry, Ramsey cell design, and systematics analysis. (We also built, many years ago, the original apparatus on which the current project is based...) |
| Collaborator Contribution | Although the collaboration is based at PSI, it encompasses many partners from around Europe. PSI is providing the source, much of the equipment, substantial manpower. (My estimate of 5 M CHF is probably wildly inaccurate.) The collaboration has existed for quite some years but we only joined it in 2014. |
| Impact | 10.1103/PhysRevD.92.092003 10.1103/PhysRevLett.115.162502 10.1103/PhysRevD.92.052008 10.1140/epjd/e2015-60207-4 10.1016/j.physletb.2014.10.046 Papers are starting to emerge... the first since I joined has been submitted for publication. |
| Start Year | 2014 |
| Description | PSI EDM |
| Organisation | University of Fribourg |
| Country | Switzerland |
| Sector | Academic/University |
| PI Contribution | We are taking on responsibility for coordination of key parts of the neutron EDM project, in particular helium magnetometry, Ramsey cell design, and systematics analysis. (We also built, many years ago, the original apparatus on which the current project is based...) |
| Collaborator Contribution | Although the collaboration is based at PSI, it encompasses many partners from around Europe. PSI is providing the source, much of the equipment, substantial manpower. (My estimate of 5 M CHF is probably wildly inaccurate.) The collaboration has existed for quite some years but we only joined it in 2014. |
| Impact | 10.1103/PhysRevD.92.092003 10.1103/PhysRevLett.115.162502 10.1103/PhysRevD.92.052008 10.1140/epjd/e2015-60207-4 10.1016/j.physletb.2014.10.046 Papers are starting to emerge... the first since I joined has been submitted for publication. |
| Start Year | 2014 |
| Description | PSI EDM |
| Organisation | University of Kentucky |
| Country | United States |
| Sector | Academic/University |
| PI Contribution | We are taking on responsibility for coordination of key parts of the neutron EDM project, in particular helium magnetometry, Ramsey cell design, and systematics analysis. (We also built, many years ago, the original apparatus on which the current project is based...) |
| Collaborator Contribution | Although the collaboration is based at PSI, it encompasses many partners from around Europe. PSI is providing the source, much of the equipment, substantial manpower. (My estimate of 5 M CHF is probably wildly inaccurate.) The collaboration has existed for quite some years but we only joined it in 2014. |
| Impact | 10.1103/PhysRevD.92.092003 10.1103/PhysRevLett.115.162502 10.1103/PhysRevD.92.052008 10.1140/epjd/e2015-60207-4 10.1016/j.physletb.2014.10.046 Papers are starting to emerge... the first since I joined has been submitted for publication. |
| Start Year | 2014 |
| Description | Neutron EDM outreach talk (Sussex Universe series) |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | Local |
| Primary Audience | Public/other audiences |
| Results and Impact | Public outreach talk "Symmetries, Scales and the Origin of Everything". Attended by a few students, quite a number of people from local community, and also some schoolchildren. Received excellent feedback from two teachers at one school, who said pupils were excited and enthused. One, who had previously only been interested in studying computing, decided to apply for a summer placement at CERN. A student enquired about working on the project with me. |
| Year(s) Of Engagement Activity | 2018 |