Microwave spectroscopic study of the hyperfine structure of antiprotonic 3He

  title={Microwave spectroscopic study of the hyperfine structure of antiprotonic 3He},
  author={Susanne Friedreich and D{\'a}niel Barna and Fritz Caspers and Andreas J Dax and Ryugo Hayano and Masaki Hori and Dezso Horvath and Bertalan Juh{\'a}sz and T. Kobayashi and Oswald Massiczek and A. Soter and Koichi Todoroki and Eberhard Widmann and Johann Zmeskal},
  journal={Journal of Physics B: Atomic, Molecular and Optical Physics},
In this work, we describe the latest results for the measurements of the hyperfine structure of antiprotonic 3He. Two out of four measurable super–super-hyperfine (SSHF) transition lines of the (n, L) = (36, 34) state of antiprotonic 3He were observed. The measured frequencies of the individual transitions are 11.125 48(08) GHz and 11.157 93(13) GHz, with the increased precisions of about 43% and 25%, respectively, compared to our first measurements with antiprotonic 3He (Friedreich et al 2011… 

Observation of the 1154.9 nm transition of antiprotonic helium

The resonance transition (n, l) = (40, 36) → (41, 35) of the antiprotonic helium (p‾4?>He+) isotope at a wavelength of 1154.9 nm was detected by laser spectroscopy. The population of p‾4?>He+

Recent progress of laser spectroscopy experiments on antiprotonic helium

  • M. Hori
  • Physics
    Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences
  • 2018
By comparing the results with three-body quantum electrodynamics calculations, the antiproton-to-electron mass ratio was determined as , which agrees with the known proton- to-electrons mass ratio with a precision of 8×10−10.

Precision laser spectroscopy experiments on antiprotonic helium

At CERN‘s Antiproton Decelerator (AD) facility, the Atomic Spectroscopyand Collisions Using Slow Antiprotons (ASACUSA) collaboration is carrying out precise laser spectroscopy experiments on

Transitions between States of the Hyperfine Structure of Antiprotonic $${}^{\mathbf{4}}$$He in Collisions with Atoms of the Medium: Interaction Ab Initio

Collisions of the metastable antiprotonic helium atoms with the atoms of the medium cause, among other processes, transitions between hyperfine structure (HFS) states, as well as shifts and

Single-photon laser spectroscopy of cold antiprotonic helium

  • M. Hori
  • Physics
    Hyperfine Interactions
  • 2018
Some laser spectroscopy experiments carried out by the Atomic Spectroscopy and Collisions Using Slow Antiprotons (ASACUSA) collaboration to measure the single-photon transition frequencies of

Laser Spectroscopy Measurements of Metastable Pionic Helium Atoms at Paul Scherrer Institute

Recent experiments carried out by the PiHe collaboration of the Paul Scherrer Institute that observed an infrared transition of three-body pionic helium atoms by laser spectroscopy may lead to a precise determination of the charged pion mass.

Recent results of laser spectroscopy experiments of pionic helium atoms at PSI

A review of a recent experiment carried out at PSI involving laser spectroscopy of metastable pionic helium and an infrared transition of atoms is presented.

Antiprotonic bound systems

  • M. Doser
  • Progress in Particle and Nuclear Physics
  • 2022



Microwave spectroscopy measurements of the hyperfine structure in antiprotonic 3He

We shall present here the first experimental results for microwave spectroscopy of the hyperfine structure of antiprotonic He-3 and a comparison to numerical simulations of the measurement. Due to

Improved study of the antiprotonic helium hyperfine structure

We report the initial results from a systematic study of the hyperfine (HF) structure of antiprotonic helium (n, l) = (37, 35) carried out at the antiproton decelerator (AD) at CERN. We performed

Hyperfine structure of antiprotonic helium revealed by a laser-microwave-laser resonance method.

This experiment confirms the quadruplet hyperfine structure arising from the interaction of the antiproton orbital angular momentum, the electron spin and the antiproachton spin as predicted by Bakalov and Korobov.

Antiprotonic helium and CPT invariance

We review recent progress in the laser and microwave spectroscopy of antiprotonic helium atoms carried out at CERN's Antiproton Decelerator facility (AD). Laser transitions were here induced between

Coupled-channel analysis of collisional effects on HFS transitions in antiprotonic helium atoms

Collisions of metastable antiprotonic helium with atoms of a medium induce transitions between hyperfine structure sublevels as well as shifts and broadenings of the microwave M1 spectral lines. We

Two-photon laser spectroscopy of antiprotonic helium and the antiproton-to-electron mass ratio

Two-photon spectroscopy of antiprotonic helium, in which 3He+ and 4He+ isotopes are irradiated by two counter-propagating laser beams, is reported, which derived an antiprodynamics mass ratio that agrees with the proton-to-electron value known to a similar precision.

Fine and hyperfine structure of the (37, 35) state of the 4He+pbar atom

Recently new calculations of the hyperfine structure (HFS) for the metastable state (37, 35) of the 4He+ atom have been performed using the variational coupled rearrangement channel method. They