Progress in precise laser spectroscopy of antiprotonic helium atomsThis paper was presented at the International Conference on Precision Physics of Simple Atomic Systems, held at École de Physique, les Houches, France, 30 May – 4 June, 2010.

2011 ◽  
Vol 89 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Masaki Hori
Keyword(s):  
Laser Spectroscopy ◽  
Optical Transition ◽  
Antiprotonic Helium ◽  
Atomic Systems ◽  
International Conference

The ASACUSA collaboration at CERN has previously measured the optical transition frequencies of antiprotonic helium to a precision of <1 part in 108 by laser spectroscopy. We describe some recent theoretical and experimental developmental work carried out by our collaboration to further improve the experimental precision.

Antiprotonic helium and kaonic helium – A tale of two exotic helium atomsThis 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.

2009 ◽  
Vol 87 (7) ◽  
pp. 835-842 ◽  
Author(s):  
R. S. Hayano
Keyword(s):  
Laser Spectroscopy ◽  
Recent Progress ◽  
Historical Background ◽  
Antiprotonic Helium ◽  
Past Study ◽  
Future Prospects ◽  
Atomic Systems ◽  
X Ray ◽  
Helium Atoms ◽  
International Conference

Recent progress on the precision laser spectroscopy of antiprotonic helium atoms, as well as on the X-ray spectroscopy of kaonic helium atoms, are presented. These two may appear to be unrelated topics (except that both involve exotic helium atoms), but in fact a past study of kaonic helium system led to the serendipitous discovery of antiprotonic helium. Some historical background connecting these two exotic helium atoms, as well as future prospects, are discussed.

scholarly journals Non-spherical proton shape and hydrogen hyperfine splittingThis 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.

2009 ◽  
Vol 87 (7) ◽  
pp. 773-783 ◽  
Author(s):  
A. J. Buchmann
Keyword(s):  
Charge Distribution ◽  
Hyperfine Splitting ◽  
Spherical Charge ◽  
Atomic Systems ◽  
Absolute Value ◽  
International Conference

We show that the non-spherical charge distribution of the proton manifests itself in hydrogen hyperfine splitting as an increase (in absolute value) of the proton Zemach radius and polarization contributions.

Laser spectroscopy of antiprotonic helium and stringent constraint on the antiproton charge and mass

2000 ◽  
Vol 663-664 ◽  
pp. 955c-958c
Author(s):  
R.S. Hayano ◽  
J. Eades ◽  
T. von Egidy ◽  
F.J. Hartmann ◽  
M. Hori ◽  
...  
Keyword(s):  
Laser Spectroscopy ◽  
Antiprotonic Helium ◽  
Stringent Constraint

scholarly journals Precision laser spectroscopy experiments on antiprotonic helium

2018 ◽  
Vol 181 ◽  
pp. 01001
Author(s):  
Masaki Hori
Keyword(s):  
Laser Spectroscopy ◽  
Quantum Electrodynamics ◽  
Single Photon ◽  
Antiprotonic Helium ◽  
Doppler Width ◽  
Electron Mass ◽  
Buffer Gas ◽  
Mass Ratio ◽  
Buffer Gas Cooling ◽  
Three Body

At CERN‘s Antiproton Decelerator (AD) facility, the Atomic Spectroscopyand Collisions Using Slow Antiprotons (ASACUSA) collaboration is carrying out precise laser spectroscopy experiments on antiprotonic helium (p̅He+ ≡ p̅+He2++e−) atoms. By employing buffer-gas cooling techniquesin a cryogenic gas target, samples of atoms were cooled to temperatureT = 1.5–1.7 K, thereby reducing the Doppler width in the single-photon resonance lines. By comparing the results with three-body quantum electrodynamics calculations, the antiproton-to-electron mass ratio was determined as Mp̅/me = 1836.1526734(15). This agreed with the known proton-to-electron mass ratio with a precision of 8 . 1010. Further improvements in the experimental precision are currently being attempted. The high-quality antiproton beam provided by the future Extra Low Energy Antiproton Ring (ELENA) facility should further increase the experimental precision.

scholarly journals Near-infrared laser spectroscopy of antiprotonic helium atoms

2014 ◽  
Vol 66 ◽  
pp. 05010
Author(s):  
T. Kobayashi ◽  
D. Barna ◽  
R. S. Hayano ◽  
Y. Murakami ◽  
K. Todoroki ◽  
...  
Keyword(s):  
Laser Spectroscopy ◽  
Near Infrared ◽  
Infrared Laser ◽  
Antiprotonic Helium ◽  
Helium Atoms ◽  
Infrared Laser Spectroscopy

The mechanisms of antihydrogen formationThis 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.

2009 ◽  
Vol 87 (7) ◽  
pp. 785-790
Author(s):  
E. Lodi Rizzini ◽  
L. Venturelli ◽  
N. Zurlo
Keyword(s):  
Preliminary Analysis ◽  
Radiative Capture ◽  
Penning Trap ◽  
Experimental Conditions ◽  
Recombination Mechanism ◽  
Atomic Systems ◽  
International Conference ◽  
Three Body ◽  
Body Recombination

Some years have passed since the report of the first production of cold antihydrogen by the Athena Collaboration and the Atrap Collaboration at CERN, but no clear answer has been given about the roles of the two mechanisms responsible for antihydrogen formation. A new preliminary analysis of the data acquired by the Athena Collaboration in different experimental conditions seems to suggest that three-body recombination mechanism is dominant in the first tens of seconds of the overlapping of the injected antiproton cloud with the positron plasma in the nested Penning trap, while radiative capture starts to become dominant afterwards.

Laser spectroscopy of antiprotonic helium atoms and ions

2005 ◽  
Vol 83 (4) ◽  
pp. 357-361 ◽  
Author(s):  
R S Hayano
Keyword(s):  
Laser Spectroscopy ◽  
Antiprotonic Helium ◽  
Helium Nucleus ◽  
Low Density ◽  
Body System ◽  
Helium Atoms ◽  
Gas Target ◽  
Helium Gas ◽  
Three Body

Laser spectroscopy of an antiprotonic helium ([Formula: see text]He+) atom, a neutral three-body Coulomb system consisting of an antiproton, a helium nucleus, and an electron has so far contributed to the determination of antiproton mass and charge to a precision of 10-8. Recently, we have succeeded in producing long-lived (τ [Formula: see text] 100 ns) antiprotonic helium ions (two-body system: [Formula: see text]He++). This was done by stopping ∼50 keV antiprotons decelerated by using an "inverse linac" (RFQD) in a very low-density helium gas target and selectively populating the ionic level by using laser tagging. It may be possible to use this two-body ion for future high-precision work.PACS Nos.: 36.10.–k, 34.90.+q, 25.43.+t

scholarly journals Towards a first observation of magneto-electric directional anisotropy and linear birefringence in gasesThis paper was presented at the International Conference on Precision Physics of Simple Atomic Systems, held at École de Physique, les Houches, France, 30 May – 4 June, 2010.

2011 ◽  
Vol 89 (1) ◽  
pp. 159-164 ◽  
Author(s):  
C. Robilliard ◽  
G. Bailly
Keyword(s):  
Recent Progress ◽  
Ring Cavity ◽  
Measurement Procedure ◽  
Linear Birefringence ◽  
Atomic Systems ◽  
International Conference ◽  
Set Up ◽  
Electric Effects ◽  
High Finesse ◽  
Frequency Metrology

In this contribution to PSAS 2010, we report on recent progress on an experiment aimed at measuring small optical directional anisotropies by frequency metrology in a high-finesse ring cavity. We focus on our first experimental goal, the measurement of magneto-electric effects in gases. After a review of the expected effects in our set-up, we present the apparatus and the measurement procedure, showing that we already have the necessary sensitivity to start novel experiments.

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