Speaker
Description
Work done with: Maxime Allemand 2 , Daniel Comparat 3 , Jules Cras 3 , Carina Killian 1 ,Chloé Malbrunot 4 , Martin Simon 1 , Christophe Siour 3 , Tim Wolz 5 , Eberhard Widmann 1 on behalf of the ASACUSA-CUSP collaboration.
1 Stefan Meyer Institute, Austria, 2 Ecole normale supérieure Paris-Saclay, France, 3 Université Paris-Saclay, CNRS, Laboratoire Aimé Cotton, France, 4 TRIUMF, Canada, 5 EP Department at CERN, Switzerland.
At the CERN Antiproton Decelerator (AD) facility antihydrogen atoms are routinely created by
charge-exchange and three-body-reactions between antiprotons and positrons/positronium. The
synthesized antihydrogen atoms allow precision tests of CPT symmetry and the study of the
influence of gravity on neutral antimatter systems, possibly shedding light on the matter-
antimatter asymmetry puzzle in the universe.
Upon formation the antihydrogen atoms predominantly occupy highly-excited Rydberg states
which exhibit radiative lifetimes up to hundreds of milliseconds. However, spectroscopic
experiments require antihydrogen atoms in their ground-state for probing the hyperfine splitting.
While trapping experiments can wait for the spontaneous decay of antihydrogen into the ground
state, in-flight experiments at the AD facility such as ASACUSA (Atomic Spectroscopy And
Collisions Using Slow Antiprotons) require a technique for rapidly stimulating the repopulation
into the ground-state, such that spectroscopic measurements can be performed in a field-free
environment.
In this context, we introduce a novel technique for rapidly stimulating the decay into the ground-
state via light-mixing of long-lived with short-lived states using THz and microwave emitters
close to the formation region. This has shown to reduce the lifetime of the Rydberg states of
interest by several orders of magnitude to some tens of microsecond. A proof-of-principle setup
has been developed for investigating the stimulated deexcitation technique on a Rydberg
hydrogen beam before being implemented on the synthesized antihydrogen atoms. The
measured influence of these light sources on the atomic state distribution and the prospects of
this technique in the context of precision measurements on antihydrogen as well as other
potential applications are presented.
