55 citations · 202 across the 22 of their papers we have counts for
23 papers
Defect Dynamics and Isomer Quenching in Th:CaF Crystals
Ming Guan, Michael Bartokos, Kjeld Beeks +16
Thorium-229 doped calcium fluoride (Th:CaF) is a leading candidate for a solid-state nuclear clock, owing to the unusually low energy of the Th isomer transitio…
Control of emission interval and timing in triggered periodic superradiance
Hideaki Hara, Riku Omoto, Noboru Sasao +6
To achieve more controllable development of coherence in solids, we investigated the effect of a trigger laser tuned to the superradiance transition wavelength on periodic superrad…
Laser Mössbauer spectroscopy of ^{229}Th
Takahiro Hiraki, Takahiko Masuda, Sayuri Takatori +23
Mössbauer spectroscopy is widely used in biochemistry, geology, and solid-state physics to obtain structural information on materials. Here, we extend this technique into the optic…
X-ray-induced quenching of the Th clock isomer in CaF
Ming Guan, Michael Bartokos, Kjeld Beeks +27
Thorium-229 has the lowest nuclear-excited state (an isomer state) at approximately 8.356 eV, making it excitable with tabletop vacuum-ultraviolet lasers. Despite the recent succes…
Analytical and numerical studies of periodic superradiance
Hideaki Hara, Yuki Miyamoto, Junseok Han +6
We conduct a theoretical study to understand the periodic superradiance observed in an Er:YSO crystal. First, we construct a model based on the Maxwell-Bloch equations for a reduce…
A method to detect the VUV photons from cooled Th:CaF crystals
Ming Guan, Michael Bartokos, Kjeld Beeks +13
Thorium-229, with its exceptionally low-energy nuclear excited state, is a key candidate for developing nuclear clocks. Th-doped CaF crystals, benefiting from calcium f…
Controlling Th isomeric state population in a VUV transparent crystal
Takahiro Hiraki, Koichi Okai, Michael Bartokos +27
The radioisotope Th-229 is renowned for its extraordinarily low-energy, long-lived nuclear first-excited state. This isomeric state can be excited by VUV lasers and the transition…
Measurement of cesium electric quadrupole transition probabilities using fluorescence spectroscopy
Jing Wang, Yuki Miyamoto, Hideaki Hara +3
Fluorescence spectra of the ( and = 3/2, 1/2) electric quadrupole transition of cesium atoms have been observed with a heated cesium vapor cell…
Macro-coherent radiative emission of neutrino pair between parity-even atomic states
M. Tashiro, B. P. Das, J. Ekman +3
A new scheme to determine the neutrino mass matrix is proposed using atomic de-excitation between two states of a few eV energy spacing. The determination of the smallest neutrino…
Energy response of X-rays under high flux conditions using a thin APD for the energy range of 6-33 keV
T. Masuda, T. Hiraki, H. Kaino +10
This paper reports on the demonstration of a high-rate energy measurement technique using a thin depletion layer silicon avalanche photodiode (Si-APD). A dedicated amplitude-to-tim…
New method of galactic axion search
M. Yoshimura, N. Sasao
An appealing candidate of the galactic dark matter is the axion, which was postulated to solve the strong CP (Charge-conjugation Parity) violation problem in the standard particle…
Determination of CP violation parameter using neutrino pair beam
M. Yoshimura, N. Sasao
Neutrino oscillation experiments under neutrino pair beam from circulating excited heavy ions are studied. It is found that detection of double weak events has a good sensitivity t…
Neutrino pair and gamma beams from circulating excited ions
M. Yoshimura, N. Sasao
We propose a new method of producing neutrino pair beam that consists of a mixture of neutrinos and anti-neutrinos of all flavors. The idea is based on a coherent neutrino pair emi…
Radiative emission of neutrino pair free of quantum electrodynamic backgrounds
M. Yoshimura, N. Sasao, M. Tanaka
A scheme of quantum electrodynamic (QED) background-free radiative emission of neutrino pair (RENP) is proposed in order to achieve precision determination of neutrino properties s…
Parity violating radiative emission of neutrino pair in heavy alkaline earth atoms of even isotopes
M. Yoshimura, N. Sasao, S. Uetake
Metastable excited states of heavy alkaline earth atoms of even isotopes are studied for parity violating (PV) effects in radiative emission of neutrino pair (RE…
Two-photon paired solitons supported by medium polarization
M. Yoshimura, N. Sasao
We derive for the first time fundamental equations that describe soliton spatial profiles consisting of two-photon mode fields and macroscopic polarization of medium. Numerical sol…
Parity violation in radiative emission of neutrino pair from metastable states of heavy alkaline earth atoms
M. Yoshimura, N. Sasao, S. Uetake
Macro-coherent atomic de-excitation involving a neutrino pair emission, radiative emission of neutrino pair (RENP) (with a photon…
Thorium isomer for radiative emission of neutrino pair
N. Sasao, S. Uetake, A. Yoshimi +2
It is proposed to use the isomer ionic ground state Th embedded in transparent crystals for precision determination of unknown neutrino parameters. Isolation from s…
Radiative emission of neutrino pair from nucleus and inner core electrons in heavy atoms
M. Yoshimura, N. Sasao
Radiative emission of neutrino pair (RENP) from atomic states is a new tool to experimentally investigate undetermined neutrino parameters such as the smallest neutrino mass, the n…
Observables in Neutrino Mass Spectroscopy Using Atoms
D. N. Dinh, S. T. Petcov, N. Sasao +2
The process of collective de-excitation of atoms in a metastable level into emission mode of a single photon plus a neutrino pair, called radiative emission of neutrino pair (RENP)…
Dynamics of two-photon paired superradiance
M. Yoshimura, N. Sasao, M. Tanaka
We develop for dipole-forbidden transition a dynamical theory of two-photon paired superradiance, or PSR for short. This is a cooperative process characterized by two photons back…
Parity violating observables in radiative neutrino pair emission from metastable atoms
M. Yoshimura, A. Fukumi, N. Sasao +1
We report on a possibility of measuring parity violating effects in radiative neutrino pair emission from metastable atoms; asymmetric angular distribution of emitted photons from…
Toward CP-even Neutrino Beam
A. Fukumi, I. Nakano, H. Nanjo +3
The best method of measuring CP violating effect in neutrino oscillation experiments is to construct and use a neutrino beam made of an ideal mixture of and of mono…