Indirect laser cooling of elementary particles

• Applicant: Privatdozent Dr. Alban Kellerbauer
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2006 to 2010
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 19595990

The antihydrogen (H) atom is the system of choice for high-precision tests of CPT/Lorentz invariance as well as the Weak Equivalence Principle. While high-precision tests of CPT have been carried out both on leptons and on baryons, antihydrogen spectroscopy holds the prospect of extending direct CPT tests to composite antimatter. Furthermore, neutral antihydrogen would allow the first-ever direct study of the gravitational attraction on antimatter. All of these tests will require H at very low temperatures well below 1 K, In 2002, the production of cold H from positrons stored at 4-15 K and antiprotons was demonstrated for the first time by two experiments installed at the CERN Antiproton Decelerator. However, most proposed high-precision experiments on antihydrogen require that the following two other challenges be met as well: (1) the confinement of neutral antihydrogen in a magnetic trap, and (2) the cooling of antihydrogen. This proposal concerns a technique which addresses the second challenge while facilitating the first. The aim of the proposed program is the development and demonstration of a novel scheme for the cooling of antiprotons to sub-mK temperatures prior to recombination. Currently no other technique exists which allows the cooling of p to these temperatures. For this purpose, antiprotons are sympathetically cooled by Coulomb interactions with negative osmium ions which in turn are laser-cooled. Osmium is the only known element whose negative ion exhibits an electric-dipole (El) transition between bound states, thereby allowing laser cooling. Due to the large p/e+ mass ratio, H will be formed essentially at the p s temperature.

• DFG Programme: Independent Junior Research Groups
• Major Instrumentation: Laser 1167.2 nm for laser cooling ; Superconducting magnet ; lasers for repumping
• Instrumentation Group: 0120 Supraleitende Labormagnete ; 5700 Festkörper-Laser