The ACME Experiment and the Search for the Electric Dipole Moment of the Electron Elizabeth Petrik West (Doyle Group, Harvard University) Wednesday, September 7, 2016 11:00 AM Physics & Astronomy Building (PAB) 4-330 AMO Physics Seminar The Standard Model of particle physics has reigned triumphant for nearly half a century, but despite its astonishing success, it still fails to account for a number of basic observations about our universe, including the conspicuous fact that our universe is composed of matter rather than antimatter or equal amounts of both. This and other outstanding mysteries have inspired efforts to posit and test theories beyond the Standard Model. I will discuss one such experimental effort on the atomic physics front: the ACME Collaboration's search for the electric dipole moment of the electron (eEDM). A measureable eEDM would evince an as-yet undiscovered mechanism for time reversal symmetry violation, which is a necessary condition for producing an excess of matter over antimatter in the early universe. The ACME experiment used uniquely advantageous features of the polar molecule thorium monoxide to produce a record-setting upper bound of 10^-28 e cm on the eEDM in 2013. Improvements to the apparatus since that time have extended the projected reach of the ongoing second-generation measurement to < 10^-29 e cm. I will discuss our general experimental approach and describe the development of an improved beam source of ThO which could yield order-of-magnitude larger signals for a third-generation ACME eEDM measurement. A nonzero eEDM, which has so far eluded observation, could point the way to the solution of the matter- antimatter asymmetry puzzle and to new laws of nature that may lie beyond the Standard Model.

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The ACME Experimentand the Search for theElectric Dipole Momentof the ElectronElizabeth Petrik West (Doyle Group, Harvard University)

Wednesday, September 7, 201611:00 AM

Physics & Astronomy Building (PAB) 4-330

AMO Physics Seminar

The Standard Model of particle physics has reigned triumphant for nearly half a century, but despite its astonishing success, it stillfails to account for a number of basic observations about our universe, including the conspicuous fact that our universe is composedof matter rather than antimatter or equal amounts of both. This and other outstanding mysteries have inspired efforts to posit andtest theories beyond the Standard Model.

I will discuss one such experimental effort on the atomic physics front: the ACME Collaboration's search for the electric dipolemoment of the electron (eEDM). A measureable eEDM would evince an as-yet undiscovered mechanism for time reversal symmetryviolation, which is a necessary condition for producing an excess of matter over antimatter in the early universe. The ACMEexperiment used uniquely advantageous features of the polar molecule thorium monoxide to produce a record-setting upper boundof 10^-28 e cm on the eEDM in 2013. Improvements to the apparatus since that time have extended the projected reach of theongoing second-generation measurement to < 10^-29 e cm. I will discuss our general experimental approach and describe thedevelopment of an improved beam source of ThO which could yield order-of-magnitude larger signals for a third-generation ACMEeEDM measurement. A nonzero eEDM, which has so far eluded observation, could point the way to the solution of the matter-antimatter asymmetry puzzle and to new laws of nature that may lie beyond the Standard Model.