Background-Free Observation of Cold Antihydrogen with Field-Ionization Analysis of Its States

Gabrielse, Gerald; Bowden, N. S.; Oxley, Paul; Speck, A.; Storry, C. H.; Tan, Joseph N.; Wessels, M.; Grzonka, D.; Oelert, W.; Schepers, G.; Sefzick, T.; Walz, J.; Pittner, Heiko; Hänsch, Theodor W.; Hessels, E. A.

doi:10.1103/physrevlett.89.213401

Cited by 527 publications

(203 citation statements)

References 18 publications

Supporting

Mentioning

197

Contrasting

Unclassified

Order By: Relevance

“…Low-energy antihydrogen was first synthesized 2 in 2002. This feat was later repeated [7][8][9] , and in 2010 antihydrogen was successfully trapped 3 to facilitate its study. It was subsequently shown that antiatoms could be held 4 for up to 1,000 s, and various measurements have been performed on antihydrogen in the context of tests of CPT symmetry [10][11][12] or gravitational studies 13 .…”

mentioning

confidence: 99%

Observation of the 1S–2S transition in trapped antihydrogen

Ahmadi

Alves

Baker

et al. 2016

Nature

130

140

View full text Add to dashboard Cite

The spectrum of the hydrogen atom has played a central part in fundamental physics over the past 200 years. Historical examples of its importance include the wavelength measurements of absorption lines in the solar spectrum by Fraunhofer, the identification of transition lines by Balmer, Lyman and others, the empirical description of allowed wavelengths by Rydberg, the quantum model of Bohr, the capability of quantum electrodynamics to precisely predict transition frequencies, and modern measurements of the 1S-2S transition by Hänsch 1 to a precision of a few parts in 10 15 . Recent technological advances have allowed us to focus on antihydrogen-the antimatter equivalent of hydrogen 2-4 . The Standard Model predicts that there should have been equal amounts of matter and antimatter in the primordial Universe after the Big Bang, but today's Universe is observed to consist almost entirely of ordinary matter. This motivates the study of antimatter, to see if there is a small asymmetry in the laws of physics that govern the two types of matter. In particular, the CPT (charge conjugation, parity reversal and time reversal) theorem, a cornerstone of the Standard Model, requires that hydrogen and antihydrogen have the same spectrum. Here we report the observation of the 1S-2S transition in magnetically trapped atoms of antihydrogen. We determine that the frequency of the transition, which is driven by two photons from a laser at 243 nanometres, is consistent with that expected for hydrogen in the same environment. This laser excitation of a quantum state of an atom of antimatter represents the most precise measurement performed on an anti-atom. Our result is consistent with CPT invariance at a relative precision of about 2 × 10 −10 .

show abstract

mentioning

confidence: 99%

Observation of the 1S–2S transition in trapped antihydrogen

Ahmadi

Alves

Baker

et al. 2016

Nature

130

140

View full text Add to dashboard Cite

show abstract

“…Two attempts, at Stanford [13] and CERN's Low-Energy Antiproton Ring [14] were thwarted by the overwhelming effect of stray electric and magnetic fields upon the electrically charged test particles. The recent production of copious amounts of cold antihydrogen ðHÞ at CERN's Antiproton Decelerator (AD) [15,16] has paved the way for high-precision gravity experiments with neutral antimatter. We have proposed the AEGIS experiment (Antimatter Experiment: Gravity, Interferometry, Spectroscopy), to be performed at CERN/AD, in order to address this important question.…”

Section: Introductionmentioning

confidence: 99%

Proposed antimatter gravity measurement with an antihydrogen beam

Kellerbauer

Amoretti²,

Белов³

et al. 2008

Nuclear Instruments and Methods in Physics Research Section B:

250

175

View full text Add to dashboard Cite

The principle of the equivalence of gravitational and inertial mass is one of the cornerstones of general relativity. Considerable efforts have been made and are still being made to verify its validity. A quantum-mechanical formulation of gravity allows for non-Newtonian contributions to the force which might lead to a difference in the gravitational force on matter and antimatter. While it is widely expected that the gravitational interaction of matter and of antimatter should be identical, this assertion has never been tested experimentally. With the production of large amounts of cold antihydrogen at the CERN Antiproton Decelerator, such a test with neutral antimatter atoms has now become feasible. For this purpose, we have proposed to set up the AEGIS experiment at 0168-583X/$ -see front matter Ó 2007 Published by Elsevier B.V.

show abstract

“…The standard model is the theory that describes particles and their fundamental interactions, although without taking into account gravitation. However, this model is known to be incomplete, which has inspired searches for physics beyond the standard model, such as tests of CPT invariance that compare the fundamental properties of matterto-antimatter equivalents at the lowest energies and with the greatest precision [12][13][14][15] . For leptons, for example, the magnetic anomalies of electron and positron were compared with a fractional uncertainty of about 2 parts per billion 4 , and by applying similar techniques to protons and antiprotons, the resulting g-factor (a proportionality constant which links the spin of a particle to its magnetic moment) comparison reached a precision of 4.4 parts per million 8 .…”

mentioning

confidence: 99%

High-precision comparison of the antiproton-to-proton charge-to-mass ratio

Ulmer

Smorra

Mooser

et al. 2015

Nature

Self Cite

142

168

View full text Add to dashboard Cite

Invariance under the charge, parity, time-reversal (CPT) transformation 1 is one of the fundamental symmetries of the standard model of particle physics. This CPT invariance implies that the fundamental properties of antiparticles and their matter-conjugates are identical, apart from signs. There is a deep link between CPT invariance and Lorentz symmetry-that is, the laws of nature seem to be invariant under the symmetry transformation of spacetimealthough it is model dependent 2 . A number of high-precision CPT and Lorentz invariance tests-using a co-magnetometer, a torsion pendulum and a maser, among others-have been performed 3 , but only a few direct high-precision CPT tests that compare the fundamental properties of matter and antimatter are available [4][5][6][7][8] . Here we report high-precision cyclotron frequency comparisons of a single antiproton and a negatively charged hydrogen ion (H 2 ) carried out in a Penning trap system. From 13,000 frequency measurements we compare the charge-to-mass ratio for the antiproton (q=m) p to that for the proton q=m ð Þ p and obtain q=m ð{12 . The measurements were performed at cyclotron frequencies of 29.6 megahertz, so our result shows that the CPT theorem holds at the atto-electronvolt scale. Our precision of 69 parts per trillion exceeds the energy resolution of previous antiproton-toproton mass comparisons 7,9 as well as the respective figure of merit of the standard model extension 10 by a factor of four. In addition, we give a limit on sidereal variations in the measured ratio of ,720 parts per trillion. By following the arguments of ref. 11, our result can be interpreted as a stringent test of the weak equivalence principle of general relativity using baryonic antimatter, and it sets a new limit on the gravitational anomaly parameter of a g {1 , 8.7 3 10 27 . The standard model is the theory that describes particles and their fundamental interactions, although without taking into account gravitation. However, this model is known to be incomplete, which has inspired searches for physics beyond the standard model, such as tests of CPT invariance that compare the fundamental properties of matterto-antimatter equivalents at the lowest energies and with the greatest precision [12][13][14][15] . For leptons, for example, the magnetic anomalies of electron and positron were compared with a fractional uncertainty of about 2 parts per billion 4 , and by applying similar techniques to protons and antiprotons, the resulting g-factor (a proportionality constant which links the spin of a particle to its magnetic moment) comparison reached a precision of 4.4 parts per million 8 . We are planning to improve this measurement by at least a factor of a thousand 16,17 . In this context, we recently reported the most precise and first direct high-precision measurement of the proton magnetic moment, with a fractional precision of 3.3 parts per billion 18 . Complementary to these efforts, spectroscopic comparisons of hydrogen and antihydrogen are underway; recent progress has been...

show abstract

Background-Free Observation of Cold Antihydrogen with Field-Ionization Analysis of Its States

Cited by 527 publications

References 18 publications

Observation of the 1S–2S transition in trapped antihydrogen

Observation of the 1S–2S transition in trapped antihydrogen

Proposed antimatter gravity measurement with an antihydrogen beam

High-precision comparison of the antiproton-to-proton charge-to-mass ratio

Contact Info

Product

Resources

About