Speaker
Joel Fajans
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/I4.407.pdf
Fundamental tests with antihydrogen atoms based on advances in
non-neutral plasma physics
J. Fajans,
U.C. Berkeley, Berkeley CA USA
Abstract: Antihydrogen can be synthesized and trapped by mixing positron and antiproton plasmas
confined in superimposed Penning-Malmberg and minimum-B trap fields. Superb control of these two
plasmas is necessary to trap antihydrogen. Recent advances in plasma physics have allowed CERN's
ALPHA collaboration to increase our trapping rate by a factor of twenty, and have allowed us to trap as
many as 1000 antihydrogen atoms simultaneously.
The work on antihydrogen is motivated by the baryogenesis problem (the scarcity of antimatter in the
University). We have measured the spin flip frequency of these antiatoms to 0.1%, and the charge of the
antiatoms to 0.7ppb; both of these studies search for CPT violations. Recently, we were able to determine
the 1s-2s transition energy by illuminating antiatoms held within a 243nm laser cavity. At an accuracy of
200ppt, this is, by some measures, approaching the most precise CPT tests, and tighter limits are expected
shortly. We have also set crude bounds on the gravitational properties of these antiatoms
(antimatter g limited by +/-100g), and are constructing a new apparatus designed to measure the
antimatter g to 1%; this is a test of the weak equivalence principle.
In this talk I will discuss some of the recent advances in plasma physics, as well as some of the results of
our CPT and weak equivalence tests.
