Fundamental Symmetry Tests with Trapped Antihydrogen: ALPHA at CERN/AD

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ALPHA is an antimatter experiment based at CERN. The ALPHA Collaboration involves scientists from 14 institutions in 7 countries. Over one-third of these scientists come from Canadian research laboratories and universities. The Canadian team (ALPHA-Canada) has members at TRIUMF, UBC, SFU, UCalgary, and YorkU. It has held major project funding from NSERC since its inception in 2005, received the 2013 NSERC Polanyi Award, and has made significant contributions to numerous ALPHA achievements.***The goal of the ALPHA project is to measure and compare the properties of 'antihydrogen' (anti-H) - the simplest atomic form of neutral antimatter - with those of ordinary hydrogen. In doing so, we directly test and challenge fundamental theories about similarities and differences (symmetries') between matter and antimatter, an issue that is arguably one of the greatest unsolved problems in physics. Since 2011, ALPHA has announced many significant and high profile milestone achievements, including: long term trapping of neutral antimatter (2011), proof of principle microwave studies (2012), gravitational force measurements on trapped anti-H(2013), in situ trap diagnostics (2013-14) and high precision measurements of the charge neutrality of anti-H [1 part in 10^8 (2014), 1 part in 10^9 (2016)].***ALPHA recently completed a major upgrade, to which ALPHA-Canada made major contributions with NSERC support. The new ALPHA-2 apparatus allows optical access to trapped anti-H for precision laser spectroscopy, experiments that are currently underway at CERN. Our contributions to ALPHA-2 included: design and fabrication of the new anti-atom trap cryostat; upgrades to the detector readout data acquisition, trap electronics, laser, and microwave systems. Work to date with ALPHA-2 includes at least 10-fold improvement in anti-H collection rates, initial probing of anti-H with cavity-stored laser light, and commissioning of a pulsed Lyman- laser system. The ALPHA-Canada team plays a prominent role in ALPHA-2 commissioning and operation, including providing leadership on detector analysis and pulsed laser system operation.***In partnership with CFI and three provinces, ALPHA-Canada and ALPHA have undertaken another infrastructure upgrade through design, construction, and fabrication of a second apparatus to run in parallel with ALPHA-2. ALPHA-g is a system designed to measure the gravitational forces on neutral anti-H and answer the question “If an antimatter apple was dropped, how would it fall?”***This proposal requests funding to support an exciting and highly-visible three-year program of research. It will result in the first-ever laser spectroscopy and cooling of atomic anti-H, improved measurements of the its hyperfine splitting at a precision that probes fundamental physics, first measurements of its Lyman- spectra, and the first-ever observation of gravitational free-fall of anti-H.