Antihydrogen Production and Precision Spectroscopy with ATHENA/AD-1 (original) (raw)

Antihydrogen production and precision experiments

Nuclear Physics B - Proceedings Supplements, 1997

03 3;; \ JV WN\H\H\WNW\\W\W\\W CERN / SPM ___,__ SPSLC/P302 cme Lmmms, cm~mvA ter at a high precision. OCR Output direct experimental tests of the Weak Equivalence Principle for antimat tihydrogen, using either ballistic or spectroscopic methods, can provide

Flawing CERN antihydrogen-experiments with the available H-spectrum

2005

Solving the H-problem could well be of historical interest but a solution must be unambiguous. We use already available and accurate spectral evidence to contradict and even to flaw the current CERN H-experiments, set up to unravel this H-mystery. Making H with a long-range interaction between e + and pis impossible, since this massasymmetrical pair of charge-conjugated antiparticles is confined to a bound state at close-range. This resembles the short-and long-range quark behavior in QCD. A real solution for H will therefore require a different approach.

Antihydrogen Physics at ALPHA/CERNThis paper was presented at the International Conference on Precision Physics of Simple Atomic Systems, held at University of Windsor, Windsor, Ontario, Canada on 21–26 July 2008

Canadian Journal of Physics, 2009

Cold antihydrogen has been produced at CERN (Amoretti et al. (Nature, 419, 456 (2002)), Gabrielse et al. (Phys. Rev. Lett. 89, 213401 (2002))), with the aim of performing a high-precision spectroscopic comparison with hydrogen as a test of the CPT symmetry. Hydrogen, a unique system used for the development of quantum mechanics and quantum electrodynamics, has been continuously used to produce high-precision tests of theories and measurements of fundamental constants and can lead to a very sensitive search for CPT violation. After the initial production of cold antihydrogen atoms by the ATHENA group, the ALPHA Collaboration (http://alpha.web.cern.ch/) has set forth on an experiment to trap and perform high-resolution laser spectroscopy on the 1S-2S transition of both atoms. In this contribution, we will review the motivations, goals, techniques, and recent developments towards this fundamental physics test. We present new discussion on predicted lineshapes for the 1S-2S spectroscopy of trapped atoms in a regime not discussed before.

Antihydrogen accumulation for fundamental symmetry tests

Nature Communications

Antihydrogen, a positron bound to an antiproton, is the simplest anti-atom. Its structure and properties are expected to mirror those of the hydrogen atom. Prospects for precision comparisons of the two, as tests of fundamental symmetries, are driving a vibrant programme of research. In this regard, a limiting factor in most experiments is the availability of large numbers of cold ground state antihydrogen atoms. Here, we describe how an improved synthesis process results in a maximum rate of 10.5 ± 0.6 atoms trapped and detected per cycle, corresponding to more than an order of magnitude improvement over previous work. Additionally, we demonstrate how detailed control of electron, positron and antiproton plasmas enables repeated formation and trapping of antihydrogen atoms, with the simultaneous retention of atoms produced in previous cycles. We report a record of 54 detected annihilation events from a single release of the trapped anti-atoms accumulated from five consecutive cycles.

Observation of Atomic Antihydrogen

Physical Review Letters, 1998

We report the background-free observation of atomic antihydrogen, produced by interactions of an antiproton beam with a hydrogen gas jet target in the Fermilab Antiproton Accumulator. We measure the cross section of the reaction pp ! He 2 p for p beam momenta between 5203 and 6232 MeV͞c to be 1.

Spectroscopy apparatus for the measurement of the hyperfine structure of antihydrogen

Hyperfine Interactions, 2014

The ASACUSA CUSP collaboration at the Antiproton Decelerator (AD) of CERN is planning to measure the ground-state hyperfine splitting of antihydrogen (H) using an atomic spectroscopy beamline. We describe here the latest developments on the spectroscopy apparatus developed to be coupled to theH production setup (CUSP).

Description and first application of a new technique to measure the gravitational mass of antihydrogen

Nature Communications, 2013

Physicists have long wondered whether the gravitational interactions between matter and antimatter might be different from those between matter and itself. Although there are many indirect indications that no such differences exist and that the weak equivalence principle holds, there have been no direct, free-fall style, experimental tests of gravity on antimatter. Here we describe a novel direct test methodology; we search for a propensity for antihydrogen atoms to fall downward when released from the ALPHA antihydrogen trap. In the absence of systematic errors, we can reject ratios of the gravitational to inertial mass of antihydrogen 475 at a statistical significance level of 5%; worst-case systematic errors increase the minimum rejection ratio to 110. A similar search places somewhat tighter bounds on a negative gravitational mass, that is, on antigravity. This methodology, coupled with ongoing experimental improvements, should allow us to bound the ratio within the more interesting near equivalence regime.