Author: Collaboration, A.C.
Paper Title Page
Antihydrogen Trapping and Probing at the Alpha-CERN Experiment  
  • E. Sarid
    NRCN, Beer-Sheva, Israel
  • A.C. Collaboration
    CERN, Geneva, Switzerland
  Precision spectroscopic comparison of hydrogen and antihydrogen (AH) holds the promise of sensitive tests of the Charge/Parity/Time (CPT) theorem and matter-antimatter equivalence. The clearest path towards realizing this goal is to hold a sample of AH atoms in an atomic trap for interrogation by electromagnetic radiation. At the ALPHA experiment in CERN, AH atoms are produced from antiprotons and positrons stored in the form of non-neutral plasmas, where the typical electrostatic potential energy per particle is on the order of eV, more than 104 times the maximum trappable kinetic energy. During the last two years ALPHA demonstrated the first trapping of AH atoms (*November 2010), the ability to hold the trapped AH atoms for 1000s (**June 2011), and the first resonant microwave interactions probing the hyperfine structure of the AH ground state (***March 2012). With microwave resonant radiation we succeeded making positron spin flips, making trapped atoms un-trappable. An upgraded version of the ALPHA experiment will allow us to progress towards microwave and laser precision spectroscopy of the trapped antihydrogen atoms.
* G.B.Andresen et al, ALPHA collaboration, Nature 468,673(2010)
** G.B.Andresen et al, ALPHA collaboration, Nature Physics,7,558(2011)
*** C. Amole, ALPHA collaboration, Nature 483, 439 (2012)