eEDM: Measurement of the electron electric dipole moment
Lead Research Organisation:
Imperial College London
Department Name: Physics
Abstract
The Standard Model of elementary particle physics predicts that the electric dipole moment of the electron (eEDM) is far too small to measure. However, modern extensions to the standard model - e.g. supersymmetric theories or other theories with additional particles or fields - predict values in the range accessible to experiment. Hence, the eEDM measurement is a search for physics beyond the standard model. Since a permanent electron EDM violates time reversal symmetry, it is also deeply connected to the important issue of CP violation and the apparent asymmetry between matter and antimatter in the universe. We are now in the middle of making the most sensitive eEDM measurement to date, a measurement that tests theories of new physics. Our method uses laser manipulation of cold polar molecules, which may eventually be trapped at ultralow temperature. This approach has the promise of improving on the precision of the eEDM search by two orders of magnitude compared with the current best measurement. In this proposal, we are seeking support for an ongoing programme of development that will allow us to realise this promise. This offers the exciting prospect of either discovering new physics through the detection of a non-zero eEDM or of excluding proposed new physics through the absence of an eEDM.
Organisations
Publications
Hudson JJ
(2011)
Improved measurement of the shape of the electron.
in Nature
Lim J
(2018)
Laser Cooled YbF Molecules for Measuring the Electron's Electric Dipole Moment.
in Physical review letters
Sauer B
(2011)
Prospects for the measurement of the electron electric dipole moment using YbF
in Physics Procedia
Skoff S
(2011)
Diffusion, thermalization, and optical pumping of YbF molecules in a cold buffer-gas cell
in Physical Review A
Wall TE
(2011)
Stark deceleration of CaF molecules in strong- and weak-field seeking states.
in Physical chemistry chemical physics : PCCP
Zhuang X
(2011)
Franck-Condon factors and radiative lifetime of the A2?1/2-X2S+ transition of ytterbium monofluoride, YbF
in Physical Chemistry Chemical Physics
Description | We were able to make the world-leading measurement of the electron's electric dipole moment, a search for CP-violating physics beyond the Standard Model. This was published in Nature [J.J. Hudson, D. Kara, B. E. Sauer, I.J. Smallman, M. R. Tarbutt, E. A. Hinds, "Improved measurement of the shape of the electron", Nature 473, 493 (2011). doi:10.1038/nature10104]. Our new result d_e=(-2.4 +/- 5.7 +/- 1.5)x10^(-28) reduces the upper bound on the electron edm by a factor of 2. This places very stringent constraints on supersymmetric models and makes MSSM rather unlikely. It puts the UK in the internationally leading position. |
Exploitation Route | The methods we have developed to make this measurement are relevant for a range of scientific applications outside particle physics, including precision measurement, physical chemistry and quantum information science. Eventually there will also be commercial applications, but not yet. |
Sectors | Energy,Other |
Description | Our result was reported on the BBC news, on National Public Radio (USA), in the Times, Guardian, and Telegraph and in the national newspapers of many other countries. Interviews were broadcast on BBC Radio News, on the radio 4 programme Material World, and on BBC 3-counties radio. Our measurement even prompted a joke on Radio 4 comedy programme The News Quiz. People are fascinated that the simple question "is the electron round" connects with such deep issues as the relation between matter and antimatter and the physics of the early universe. This type of impact inspires young students to take up science and excites the public in general. Public interest is a prerequisite for engaging politicians in science. |
First Year Of Impact | 2011 |
Sector | Energy |
Description | An improved measurement of the electron electric dipole moment using YbF molecules |
Amount | £913,892 (GBP) |
Funding ID | EP/J011401/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 03/2012 |
End | 01/2017 |
Description | ERC Advanced Grants |
Amount | £1,853,561 (GBP) |
Funding ID | 320789 |
Organisation | European Research Council (ERC) |
Sector | Public |
Country | Belgium |
Start | 02/2013 |
End | 01/2018 |
Description | Particle Physics Consolidated Grant - Measurement of the eEDM |
Amount | £724,632 (GBP) |
Funding ID | ST/N000242/1 |
Organisation | Science and Technologies Facilities Council (STFC) |
Sector | Public |
Country | United Kingdom |
Start | 10/2015 |
End | 09/2019 |
Description | Research Grant - Measurement of the electron edm: eEDM (CG) |
Amount | £83,183 (GBP) |
Funding ID | ST/K001604/1 |
Organisation | Science and Technologies Facilities Council (STFC) |
Sector | Public |
Country | United Kingdom |
Start | 10/2012 |
End | 09/2016 |