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Your search keyword '"O'neil, G. C."' showing total 3 results
Start Over Author "O'neil, G. C." Publisher american physical society

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3 results on '"O'neil, G. C."'

1. Proof-of-Principle Experiment for Testing Strong-Field Quantum Electrodynamics with Exotic Atoms: High Precision X-Ray Spectroscopy of Muonic Neon.

Author

Okumura T, Azuma T, Bennett DA, Chiu I, Doriese WB, Durkin MS, Fowler JW, Gard JD, Hashimoto T, Hayakawa R, Hilton GC, Ichinohe Y, Indelicato P, Isobe T, Kanda S, Katsuragawa M, Kawamura N, Kino Y, Mine K, Miyake Y, Morgan KM, Ninomiya K, Noda H, O'Neil GC, Okada S, Okutsu K, Paul N, Reintsema CD, Schmidt DR, Shimomura K, Strasser P, Suda H, Swetz DS, Takahashi T, Takeda S, Takeshita S, Tampo M, Tatsuno H, Ueno Y, Ullom JN, Watanabe S, and Yamada S

Abstract

To test bound-state quantum electrodynamics (BSQED) in the strong-field regime, we have performed high precision x-ray spectroscopy of the 5g-4f and 5f- 4d transitions (BSQED contribution of 2.4 and 5.2 eV, respectively) of muonic neon atoms in the low-pressure gas phase without bound electrons. Muonic atoms have been recently proposed as an alternative to few-electron high-Z ions for BSQED tests by focusing on circular Rydberg states where nuclear contributions are negligibly small. We determined the 5g_{9/2}- 4f_{7/2} transition energy to be 6297.08±0.04(stat)±0.13(syst)  eV using superconducting transition-edge sensor microcalorimeters (5.2-5.5 eV FWHM resolution), which agrees well with the most advanced BSQED theoretical prediction of 6297.26 eV.

Published
2023
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2. Measurements of Strong-Interaction Effects in Kaonic-Helium Isotopes at Sub-eV Precision with X-Ray Microcalorimeters.

Author

Hashimoto T, Aikawa S, Akaishi T, Asano H, Bazzi M, Bennett DA, Berger M, Bosnar D, Butt AD, Curceanu C, Doriese WB, Durkin MS, Ezoe Y, Fowler JW, Fujioka H, Gard JD, Guaraldo C, Gustafsson FP, Han C, Hayakawa R, Hayano RS, Hayashi T, Hays-Wehle JP, Hilton GC, Hiraiwa T, Hiromoto M, Ichinohe Y, Iio M, Iizawa Y, Iliescu M, Ishimoto S, Ishisaki Y, Itahashi K, Iwasaki M, Ma Y, Murakami T, Nagatomi R, Nishi T, Noda H, Noumi H, Nunomura K, O'Neil GC, Ohashi T, Ohnishi H, Okada S, Outa H, Piscicchia K, Reintsema CD, Sada Y, Sakuma F, Sato M, Schmidt DR, Scordo A, Sekimoto M, Shi H, Shirotori K, Sirghi D, Sirghi F, Suzuki K, Swetz DS, Takamine A, Tanida K, Tatsuno H, Trippl C, Uhlig J, Ullom JN, Yamada S, Yamaga T, Yamazaki T, and Zmeskal J

Abstract

We have measured the 3d→2p transition x rays of kaonic ^{3}He and ^{4}He atoms using superconducting transition-edge-sensor microcalorimeters with an energy resolution better than 6 eV (FWHM). We determined the energies to be 6224.5±0.4(stat)±0.2(syst)  eV and 6463.7±0.3(stat)±0.1(syst)  eV, and widths to be 2.5±1.0(stat)±0.4(syst)  eV and 1.0±0.6(stat)±0.3(stat)  eV, for kaonic ^{3}He and ^{4}He, respectively. These values are nearly 10 times more precise than in previous measurements. Our results exclude the large strong-interaction shifts and widths that are suggested by a coupled-channel approach and agree with calculations based on optical-potential models.

Published
2022
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3. Deexcitation Dynamics of Muonic Atoms Revealed by High-Precision Spectroscopy of Electronic K X Rays.

Author

Okumura T, Azuma T, Bennett DA, Caradonna P, Chiu I, Doriese WB, Durkin MS, Fowler JW, Gard JD, Hashimoto T, Hayakawa R, Hilton GC, Ichinohe Y, Indelicato P, Isobe T, Kanda S, Kato D, Katsuragawa M, Kawamura N, Kino Y, Kubo MK, Mine K, Miyake Y, Morgan KM, Ninomiya K, Noda H, O'Neil GC, Okada S, Okutsu K, Osawa T, Paul N, Reintsema CD, Schmidt DR, Shimomura K, Strasser P, Suda H, Swetz DS, Takahashi T, Takeda S, Takeshita S, Tampo M, Tatsuno H, Tong XM, Ueno Y, Ullom JN, Watanabe S, and Yamada S

Abstract

We observed electronic K x rays emitted from muonic iron atoms using superconducting transition-edge sensor microcalorimeters. The energy resolution of 5.2 eV in FWHM allowed us to observe the asymmetric broad profile of the electronic characteristic Kα and Kβ x rays together with the hypersatellite K^{h}α x rays around 6 keV. This signature reflects the time-dependent screening of the nuclear charge by the negative muon and the L-shell electrons, accompanied by electron side feeding. Assisted by a simulation, these data clearly reveal the electronic K- and L-shell hole production and their temporal evolution on the 10-20 fs scale during the muon cascade process.

Published
2021
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