Recent progress of SPAN towards neutrino mass spectroscopy

14th International Conference on Topics in Astroparticle and Underground Physics

物理学;天文学

Masuda, T.^1 ; Hara, H.^1 ; Miyamoto, Y.^1 ; Sasao, N.^1 ; Tanaka, M.^2 ; Uetake, S.^3 ; Yoshimi, A.^1 ; Yoshimura, K.^1 ; Yoshimura, M.^3

Research Core for Extreme Quantum World, Okayama University, Okayama

700-8530, Japan^1

Department of Physics, Osaka University, Toyonaka, Osaka

560-0043, Japan^2

Research Center of Quantum Universe, Okayama University, Okayama

700-8530, Japan^3

关键词: Enhancement factor;    Metastable levels;    Mid-infrared laser pulse;    Neutrino pairs;    Photon energy spectrum;    Recent progress;    Two-photon emission;    Vibrationally excited state;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/718/6/062043/pdf
DOI  :  10.1088/1742-6596/718/6/062043

学科分类：天文学(综合)

来源: IOP

【 摘 要 】

SPAN (Spectroscopy of Atomic Neutrino) project aims to determine the absolute neutrino mass. The process we plan to use is a cooperative de-excitation of atoms in a metastable level emitting a neutrino pair associated with a photon. The photon energy spectrum of this process contains information on the absolute mass of neutrino. Key items of this experiment are a rate amplification using macro-coherence in a target medium in case of plural particles emission and an external triggering of the emission in order to scan the spectrum. We have demonstrated the rate amplification in two-photon emission from para-hydrogen gas which was coherently excited to its first vibrationally excited state. The coherence in the medium was generated by irradiating two driving laser pulses. The emission was stimulated by irradiating a mid-infrared laser pulse. The enhancement factor of more than 1018with respect to the spontaneous emission was achieved. This paper briefly summarizes the results.