Scientific Commons: H. A. Torii

For the precise measurement of the hyperfine structure of antiprotonic helium microwave radiation of 12.9 GHz frequency is needed, tunable over ±100 MHz. A cylindrical microwave cavity is used whose...

Cryogenic Tunable Microwave Cavity at 13 GHz for Hyperfine Spectroscopy of Antiprotonic Helium (2005)

Barna, D, Caspers, Friedhelm, Eades, John, Gilg, H, Hayano, R S, Hori, Masaki, ...

For the precise measurement of the hyperfine structure of antiprotonic helium microwave radiation of 12.9 GHz frequency is needed, tunable over ±100 MHz. A cylindrical microwave cavity is used whose...

Systematic study of the decay rates of antiprotonic helium states (2004)

Yamaguchi, H, Hayano, R S, Ishikawa, T, Sakaguchi, J, Widmann, E, Eades, John, ...

A systematic study of the decay rates of antiprotonic helium (\pbhef and \pbhet) at CERN AD (Antiproton Decelerator) has been made by a laser spectroscopic method. The decay rates of some of its...

Systematic study of the decay rates of antiprotonic helium states (2004)

Yamaguchi, H., Hayano, R. S., Ishikawa, T., Sakaguchi, J., Widmann, E., Eades, J., ...

A systematic study of the decay rates of antiprotonic helium (\pbhef and \pbhet) at CERN AD (Antiproton Decelerator) has been made by a laser spectroscopic method. The decay rates of some of its...

Direct observation of the initial-state distribution of the first electron transferred to slow highly charged ions interacting with a metal surface (2004)

Morishita, Y., Hutton, R., Torii, H. A., Komaki, K., Brage, T., Ando, K., ...

The electron transfer process in the interaction of a slow highlycharged ion with a metal surface has been studied employing amicrocapillary foil as a target. The combination of the target and...

Precise laser spectroscopy of the antiprotonic helium atom and CPT test on antiproton mass and charge (2003)

Yamaguchi, H, Eades, John, Hayano, R S, Hori, Masaki, Horváth, D, Ishikawa, T, ...

We have measured twelve transition frequencies of the antiprotonic helium atom (pbar-He+) with precisions of 0.1--0.2 ppm using a laser spectroscopic method. The agreement between the experiment and...

Precise laser spectroscopy of the antiprotonic helium atom and CPT test on antiproton mass and charge (2003)

Yamaguchi, H., Eades, J., Hayano, R. S., Hori, M., Horvath, D., Ishikawa, T., ...

We have measured twelve transition frequencies of the antiprotonic helium atom (pbar-He+) with precisions of 0.1--0.2 ppm using a laser spectroscopic method. The agreement between the experiment and...

Hyperfine structure of antiprotonic helium revealed by a laser-microwave-laser resonance method (2002)

Widmann, E, Hayano, R S, Ishikawa, T, Sakaguchi, J, Tasaki, T, Yamaguchi, H, ...

Using a newly developed laser-microwave-laser resonance method, we observed a pair of microwave transitions between hyperfine levels of the $(n,L)=(37,35)$ state of antiprotonic helium. This...

Hyperfine structure of antiprotonic helium revealed by a laser-microwave-laser resonance method (2002)

Widmann, E., Hayano, R. S., Ishikawa, T., Sakaguchi, J., Tasaki, T., Yamaguchi, H., ...

Using a newly developed laser-microwave-laser resonance method, we observed a pair of microwave transitions between hyperfine levels of the $(n,L)=(37,35)$ state of antiprotonic helium. This...

Hyperfine Structure Measurements of Antiprotonic Helium and Antihydrogen (2001)

Widmann, E, Eades, John, Hayano, R S, Hori, Masaki, Horváth, D, Ishikawa, T, ...

This paper describes measurements of the hyperfine structure of two antiprotonic atoms that are planned at the Antiproton Decelerator (AD) at CERN. The first part deals with antiprotonic helium, a...

Hyperfine Structure Measurements of Antiprotonic Helium and Antihydrogen (2001)

Widmann, E., Eades, J., Hayano, R. S., Hori, M., Horvath, D., Ishikawa, T., ...

This paper describes measurements of the hyperfine structure of two antiprotonic atoms that are planned at the Antiproton Decelerator (AD) at CERN. The first part deals with antiprotonic helium, a...

Hyperfine Structure Measurements of Antiprotonic Helium and Antihydrogen (2001)

Widmann, E, Eades, John, Hayano, R S, Hori, Masaki, Horváth, D, Ishikawa, T, ...

This paper describes measurements of the hyperfine structure of two antiprotonic atoms that are planned at the Antiproton Decelerator (AD) at CERN. The first part deals with antiprotonic helium, a...

High-precision laser spectroscopy of antiprotonic helium atomcules and effects of collisions at high-density conditions (1999)

Torii, H A

Laser Measurements of the Density Shifts of Resonance Lines in Antiprotonic Helium Atoms and Stringent Constraint on the Antiproton Charge and Mass (1999)

Torii, H A, Hayano, R S, Hori, Masaki, Ishikawa, T, Morita, N, Kumakura, M, ...

Quenching of metastable states of antiprotonic helium atoms by collisions with H$_2$ molecules (1998)

Ketzer, B, Hartmann, F J, Von Egidy, T, Maierl, C, Pohl, R, Eades, John, ...

Laser resonance transitions between normally metastable states of antiprotonic helium atoms were induced making use of state dependent quenching effects caused by trace admixtures of \mbox{H$_2$}\ to...

Hydrogen-assisted laser-induced resonant transitions between metastable states of antiprotonic helium atoms (1997)

Ketzer, B, Hartmann, F J, Von Egidy, T, Maierl, C, Pohl, R, Eades, John, ...

Laser resonance transitions between normally metastable states of antiprotonic helium atoms were observed making use of state dependent quenching effects caused by small admixtures of \htwo\...

High-Precision Structural Studies of the Antiproton Helium Atom $\overline{p}^{4}He^+$ by Observing Laser Resonances with $\Delta v = \Delta (n-l-1) = 2$ (1996)

Yamazaki, T, Widmann, E, Eades, John, Kumakura, M, Morita, N, Torii, H A, ...

Very weak laser resonances of unfavoured transitions $(n,l) \rightarrow (n+1,l-1)$ have been observed in metastable \={p}$^4$He$^+$ atoms by using a pulsed antiproton beam. The observed wavelengths...

High-Precision Structural Studies of the Antiproton Helium Atom $\overline{p}^{4}He^+$ by Observing Laser Resonances with $\Delta v = \Delta (n-l-1) = 2$ (1996)

Yamazaki, T, Widmann, E, Eades, John, Kumakura, M, Morita, N, Torii, H A, ...

Very weak laser resonances of unfavoured transitions $(n,l) \rightarrow (n+1,l-1)$ have been observed in metastable \={p}$^4$He$^+$ atoms by using a pulsed antiproton beam. The observed wavelengths...

Observation of double resonant laser induced transitions in the $v = n - l - 1 = 2$ metastable cascade of antiprotonic helium-4 atoms (1996)

Hayano, R S, Ishikawa, T, Tamura, H, Torii, H A, Hori, Masaki, Maas, F E, ...

A new laser-induced resonant transition in the $v=n-l-1=2$ metastable cascade of antiprotonic $^4$He atoms has been found by using a double resonance technique. This was done by setting the first...

Laser-induced resonant transitions in the v=n-l-1=2 and 3 metastable cascades of antiprotonic $^{3}He atoms (1995)

Torii, H A, Hori, Masaki, Ishikawa, T, Maas, F E, Hayano, R S, Morita, N, ...

Laser-induced resonant transitions in metastable antiprotonic ^3He atoms have been found. The observed transitions at wavelengths 593.388 \pm 0.001~nm and at 463.947 \pm 0.002~nm have been...

Isotope Effects on Delayed Annihilation Time Spectra of Antiprotonic Helium Atoms in Low-Temperature Gas (1995)

Ketzer, B, Hartmann, F J, Daniel, H, Von Egidy, T, Niestroj, A, Schmid, S, ...

The delayed annihilation time spectra (DATS) of antiprotonic helium atoms have been studied in isotopically pure low temperature ^3He and ^4He gas at various densities. The DATS taken at 5.8~K and...

Laser studies of the decay chain of metastable antiprotonic helium atoms (1994)

Hayano, R S, Maas, F E, Torii, H A, Morita, N, Kumakura, M, Yamazaki, T, ...

First observation of laser-induced resonant annihilation in metastable antiprotonic helium atoms (1993)

Morita, N, Kumakura, M, Yamazaki, T, Widmann, E, Masuda, H, Sugai, I, ...

H. A. Torii

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