Finite-element calculations of the antiprotonic helium atom including relativistic and QED corrections

Elander, Nils; Yarevsky, E. A.

doi:10.1103/physreva.56.1855

Cited by 41 publications

(27 citation statements)

References 39 publications

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“…IV.B.5): the energy eigenvalues for the p have now been calculated to a level of Ϸ5 ppm (Korobov, 1996) by including relativistic terms in the electron's motion. Even closer agreement is obtained when the Lamb shift is taken into account (Elander and Yarevsky, 1997). A detailed study of the fine and hyperfine structure of the transitions between high-lying levels in p -He could, for example, provide a much improved remeasurement of the magnetic moment of the antiproton.…”

Section: B Antiprotonic Helium and Protoniummentioning

confidence: 63%

Forty years of antiprotons

Eades

Hartmann

1999

Rev. Mod. Phys.

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The discovery of the antiproton some 40 years ago and the almost synchronous fall of parity (P) and charge conjugation (C) symmetries were soon followed by the realization that CPT rather than C invariance is the fundamental symmetry connecting matter and antimatter, and that consequently any measurement of the antiproton's properties can be interpreted as a test of that symmetry. It is the latter view of the antiproton, as an object of study in its own right, rather than as a means to such other ends as the production of gauge bosons and meson resonances, that is presented here. The authors review the technical steps that have led from the handful of antiprotons observed by Chamberlain, Segrè , Wiegand, and Ypsilantis to the intense, high-quality beams available today and show how the state of rest and isolation required for high precision measurements of their properties can be achieved by confining them in electromagnetic traps or in their microscopic counterparts, exotic atoms. The test bench role of antiprotons and antihydrogen atoms for both CPT symmetry and the gravitational weak equivalence principle is discussed, and the body of experimental results obtained since 1955 critically reviewed from this standpoint. Future experiments are then discussed in the light of the closure of the CERN Low Energy Antiproton Ring (LEAR), its replacement in 1999 by the Antiproton Decelerator (AD), and the likely antiproton source at the Japan Hadron Facility.[S0034-6861(99)00401-8] CONTENTS

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Section: B Antiprotonic Helium and Protoniummentioning

confidence: 63%

Forty years of antiprotons

Eades

Hartmann

1999

Rev. Mod. Phys.

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“…Some of these resonance states have a very long lifetime ( 1 ps) against (Auger) decay channels and were vigorously investigated in laser spectroscopic experiments [11,12]. The atomic properties of antiprotonic helium measured in the experiments can be compared with elaborate calculations based on the variational method [13][14][15][16][17]. The high-precision study of antiprotonic helium has an important contribution to the determination of fundamental physical constants such as thep mass [11,12].…”

Section: Introductionmentioning

confidence: 99%

Cross sections for antiproton capture by helium ions

Sakimoto

2010

Phys. Rev. A

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Accurate quantum-mechanical calculations are carried out for antiproton capture by singly ionized He ions, that is,p + He + →pHe 2+ + e, by the combined use of an R-matrix method and direct numerical solution. The total capture cross sections (or collision strengths) and the state distributions of the capture products,pHe 2+ , are calculated at collision energies ranging from 0 to 4 eV. The present system is rich in resonances, which appear as a Rydberg series and are characterized as an electron attached to an ion core,pHe 2+ . Some resonance levels can be reproduced by a reasonable model based on molecular-quantum-defect theory. The capture into the highest energetically possible state of the products,pHe 2+ , always takes place overwhelmingly in the presence or absence of the resonances. However, owing to the resonances, the angular momentum distribution of the products varies considerably depending on the collision energy. The energy-averaged capture cross sections and the capture rate coefficients are also presented for the convenience of future experiments.

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“…These ambitious goals, however, may only be achieved if theoretical calculations reach the same or better precision. A lot of work has already been done to this end, including the calculation of the pure Coulomb energy levels of thepHe 1 atoms with an accuracy of 10 211 [10,20], the evaluation of the leading O͑a 2 ͒ QED and relativistic corrections [21] and hyperfine splittings of the levels [22], the leading part of the Lamb shift [23], the estimate of the particle electromagnetic structure effects [21], etc., so that the uncertainty of theoretical values of the energy levels of isolatedpHe 1 atoms is now believed to not exceed 1 ppm. The experiments are performed, however, at finite densities of the target helium gas, for which the collisions ofpHe 1 with the surrounding He atoms are known to significantly distort the spectrum: the density shift of the 597 nm line at 1 bar reaches 10 ppm [24,25].…”

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confidence: 99%

Density Shift and Broadening of Transition Lines in Antiprotonic Helium

Bakalov

Jeziorski²,

Korona³

et al. 2000

Phys. Rev. Lett.

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The density shift and broadening of the transition lines of antiprotonic helium have been evaluated in the impact approximation using an interatomic potential calculated ab initio with the symmetry-adapted perturbation theory. The results help to remove an uncertainty of up to 10 ppm in the laser spectroscopy data on antiprotonic helium and are of importance in experimental tests of bound state QED and CPT invariance.

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Finite-element calculations of the antiprotonic helium atom including relativistic and QED corrections

Cited by 41 publications

References 39 publications

Forty years of antiprotons

Forty years of antiprotons

Cross sections for antiproton capture by helium ions

Density Shift and Broadening of Transition Lines in Antiprotonic Helium

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