Test of macro-coherent amplification by observing phase conjugate wave toward neutrino mass spectroscopy

2018 Fiscal Year Final Research Report

• Project/Area Number: 17K18779
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Research Field: Particle-, Nuclear-, Astro-physics, and related fields
• Research Institution: Okayama University
• Principal Investigator: Miyamoto Yuki 岡山大学, 異分野基礎科学研究所, 特任講師 (00559586)
• Project Period (FY): 2017-06-30 – 2019-03-31
• Keywords: ニュートリノ質量分光 / 位相共役波 / 水素分子 / 二光子放出

Outline of Final Research Achievements

Coherence amplification is an essential process for neutrino mass spectroscopy. We have verified the mechanism under the same geometry as the neutrino mass spectroscopy by observing phase-conjugate two-photon emission from vibrational state of gaseous hydrogen molecules excited by counter-propagating laser pulses. The observed results agree with calculations by Maxwell-Bloch equations or their simplified versions. Furthermore, we observed the two-photon emission from solid hydrogen. Solid hydrogen is known as quantum solid and have high density and long coherence time. It was found that mutual timing dependence of the two-photon emission is different from that of the third harmonics which is observed simultaneously. This result indicates the importance of the geometry on coherence amplification. Further works are desired to understand this phenomenon.

Free Research Field

分子科学

Academic Significance and Societal Importance of the Research Achievements

ヒッグス粒子の発見により素粒子の標準理論が完成した現在、素粒子研究は標準理論を超える物理を探求するフェーズに移行した。そこで突破口の一つと考えられるのが、未だ謎の多いニュートリノである。そのためニュートリノ質量分光によりニュートリノの未知の性質を明らかにすることは重要である。本研究によりニュートリノ質量分光の重要要素であるコヒーレンス増幅の検証は充分なレベルに達し、今後、研究は新たな段階に進むことになる。本研究の成果の意義は大きい。