| 研究実績の概要 |
We have made significant progress in understanding the signals which arise from axion stars. Building on work with colleagues at IPMU (now published, Phys. Lett. B825 (2022) 136858), I have been investigating the signals from collapsing axion stars which interact with photons or electrons inside of quantum sensor experiments; our analysis, nearly complete, shows a significant increase in the reach of direct detection experiments over a wide range of axion parameters. A second novel signal I have investigated arises from the build-up of high-energy axions over long astrophysical timescales, which can give rise to a 'background' of particles which can be searched for in the same experiments. We have also developed the framework to analyze photon signals from this axion background, which can arise due to axion interactions with intergalactic magnetic fields. These all provide novel and important signals for direct searches.
In another work, now in preprint, we investigated a new model of an axion-like particle which is connected to the Higgs hierarchy problem. This work provides a simple but promising new target for direct searches, including those described above.
Finally, we have developed a simple framework to understand the formation of axion bound states, which will appear in a completed research paper in the coming months.
|
| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
The progress along the lines of this research proposal have been mostly smooth, and we have been able to propose a number of new search strategies to hasten the discovery of axion dark matter. New ideas, including the detection of axion bursts with quantum sensors, have arisen from these discussions in an unanticipated way, and provide exceptional sensitivity to these signals. The core of the project, which is the discovery of new signals from axion stars, has continued as planned.
|
| 今後の研究の推進方策 |
We are finalizing the research papers related to (1) quantum sensors to detect axion bursts, (2) the axion background from the build-up of many bursts from axion stars, and (3) the formation of axion overdensities. The physics is well-understood at this point, and progress from here is expected to be very smooth as we write up the results.
|
