表題番号：2018B-133
日付：2019/04/05
研究課題Analysis of the CALET Electron+Positron Cosmic-Ray Spectrum for Dark Matter Signatures
| 研究者所属（当時） | 資格 | 氏名 | |
|---|---|---|---|
| （代表者） | 理工学術院 国際理工学センター（理工学術院） | 准教授 | モッツ ホルガー マルティン |
| （連携研究者） | 理工学術院 先進理工学研究科 | PhD Student | Saptashwa Bhattacharyya |
- 研究成果概要
- This project focused on the scientific analysis of data from the CALET cosmic-ray detector on the ISS for signatures of Dark Matter.
Previously calculated limits on Dark Matter annihilation and decay from CALET data were refined. The limit calculation is based on a parametrization of the spectra from astrophysical sources fitted to CALET (electron+positron) and AMS-02 (positron-only) data, to which the expected flux from Dark Matter is added until the model is excluded, yielding a limit.
The parametrization of the pulsar source assumed to cause the positron excess was improved from a generic power law with exponential cut-off to a semi-analytically calculated spectrum for individual known pulsars. The combined spectrum of multiple pulsars fits significantly better than a single pulsar, modelling better a step-like spectral structure at 350 GeV.
Alternative to multiple pulsars, a Dark Matter explanation is also possible, assuming a single pulsar background, which is also applicable to a step at 1 TeV not explainable by nearby pulsars.
A model of leptonic three-body Dark Matter decay as the only source of the positron excess was published in a refereed journal after improving the discussion of constraints from gamma-ray observation.