nEDM Collaboration

nEDM Collaboration
Name	nEDM Collaboration
Formed	1990s
Members	multiple international institutions
Location	Europe, North America
Fields	Fundamental physics, Particle physics, Nuclear physics

nEDM Collaboration

The nEDM Collaboration is an international research consortium focused on measuring the electric dipole moment of the neutron, seeking signals that would impact theories involving Charge Parity, CP violation, Standard Model extensions and cosmological explanations such as Baryogenesis and Matter–antimatter asymmetry. The collaboration brings together experimental groups, theoretical teams, and large-scale facilities to perform ultra-sensitive measurements that test predictions from models including Supersymmetry, Left–right symmetry, and axion-related scenarios such as the Peccei–Quinn theory.

Overview

The collaboration operates at the interface of Particle physics, Nuclear physics, and precision measurement, combining expertise from institutions that have also contributed to initiatives like Large Hadron Collider, ISIS Neutron and Muon Source, Institut Laue–Langevin, European Organization for Nuclear Research, and national laboratories such as Oak Ridge National Laboratory and Fermi National Accelerator Laboratory. Its work addresses questions central to proposals by theorists associated with Steven Weinberg, Gerard 't Hooft, and John Ellis, and it employs methods connected to experiments like UCNτ, SNS nEDM, and historical efforts at Institut Laue–Langevin and Paul Scherrer Institute.

History and Formation

The collaboration formed from groups that previously participated in neutron electric dipole moment searches at institutions including Institut Laue–Langevin, Paul Scherrer Institute, Los Alamos National Laboratory, and University of Sussex. Early institutional linkages trace to programs influenced by work at Harvard University, Columbia University, and University of Oxford. Funding and coordination involved agencies and programs such as European Research Council, UK Research and Innovation, National Science Foundation, and national laboratories exemplified by Brookhaven National Laboratory and Argonne National Laboratory.

Scientific Goals and Motivation

Primary goals include placing stringent limits on the neutron electric dipole moment to constrain sources of CP violation beyond the Kobayashi–Maskawa theory and to test mechanisms relevant to Baryogenesis and Electroweak baryogenesis. Results inform model-building in frameworks including Supersymmetry, Grand Unified Theory, Left–right symmetry, and scenarios invoking the QCD axion. Constraints from the collaboration complement searches at experiments such as ATLAS, CMS, and precision programs at J-PARC, enabling cross-disciplinary comparisons with work by theorists like Andrei Sakharov and experimentalists associated with Richard Garwin.

Experimental Methods and Facilities

Techniques center on ultracold neutron (UCN) storage, Ramsey resonance methods, magnetic shielding, comagnetometry with atoms such as 199Hg and 3He, and use of superconducting quantum interference devices developed alongside groups at Rutherford Appleton Laboratory, Paul Scherrer Institute, and Institut Laue–Langevin. Facilities contributing infrastructure include Institut Laue–Langevin, Paul Scherrer Institute, ISIS Neutron and Muon Source, Spallation Neutron Source, and university laboratories at University of Sussex, University of Manchester, and Technische Universität München. Instrumentation development drew on expertise from collaborations with National Institute of Standards and Technology and technology from groups linked to Max Planck Society and Lawrence Berkeley National Laboratory.

Collaborations and Key Institutions

Key institutional partners include Institut Laue–Langevin, Paul Scherrer Institute, Rutherford Appleton Laboratory, Spallation Neutron Source, Oak Ridge National Laboratory, Los Alamos National Laboratory, Brookhaven National Laboratory, University of Sussex, Technische Universität München, University of Oxford, Harvard University, and Columbia University. The collaboration maintains ties with funding and coordination bodies such as European Research Council, UK Research and Innovation, National Science Foundation, and national ministries associated with Germany, France, United Kingdom, and United States. Scientific exchange occurs at conferences like International Conference on Precision Physics of Small Magnetic Fields and workshops connected to Neutron2018 and meetings organized by the American Physical Society and European Physical Society.

Major Results and Publications

The collaboration has produced high-impact limits on the neutron electric dipole moment, published in peer-reviewed journals that also disseminated results from related programs at Institut Laue–Langevin and Paul Scherrer Institute. Papers are commonly cited alongside landmark experimental reports from Los Alamos National Laboratory and theoretical analyses by authors affiliated with CERN and leading universities. These publications influenced constraints used in global fits by groups working on Supersymmetry phenomenology and axion searches, and they are discussed in reviews appearing in venues associated with Reviews of Modern Physics and proceedings from International Conference on High Energy Physics.

Future Plans and Upgrades

Planned upgrades include new UCN sources, improved magnetic shielding, advanced comagnetometers using 3He or 129Xe, integration with cryogenic techniques developed in collaboration with Paul Scherrer Institute and Technische Universität München, and proposals for next-generation experiments at Spallation Neutron Source and Institut Laue–Langevin. These initiatives aim to reach sensitivities that probe parameter space relevant to Supersymmetry, Left–right symmetry, and Peccei–Quinn theory, while coordinating with collider programs at CERN and precision searches at J-PARC to provide complementary constraints.

Category:Physics collaborations