2006 Fiscal Year Final Research Report Summary
Search for cosmic-ray anti-protons produced through Hawking radiation of primordial black holes
| Project/Area Number |
15340077
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Particle/Nuclear/Cosmic ray/Astro physics
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| Research Institution | High Energy Accelerator Research Organization (2006)
Kobe University (2003-2005) |
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Principal Investigator |
NOZAKI Mitsuaki High Energy Accelerator Research Organization, Institute of Particle and Nuclear Studies, Professor (10156193)
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| Project Period (FY) |
2003 – 2006
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| Keywords | antiproton / cosmic-ray / balloon / Antarctica / Hawking radiation / Primordial black hole |
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| Research Abstract |
The purpose of this program is to search for cosmic-ray antiprotons produced through Hawking radiation of primordial black holes at the top of the atmosphere by using a balloon-borne apparatus. Keys to this experiment are an apparatus capable of measuring low energy antiprotons below 1 GeV characteristic of Hawking radiation and a long duration flight at Antarctica to improve statistics.
We have developed time-of-flight (TOF) counters and middle-TOF counters and related read-out electronics. The TOF counters are used to distinguish antiprotons from electron. The middle-TOF counters installed in a small gap between a central tracker and a cryostat are used to trigger low energy particles that cannot penetrate a superconducting coil.
In December 2004, the BESS-Polar spectrometer was launched from McMurdo base in Antarctica. A total of 432 antiproton events were recorded in a 8.5 day flight. The number of antiprotons was 4 times larger than previous flight. We have measured antiprotons below 0.2 GeV for the first time. The energy spectrum obtained in this experiment is consistent with a secondary production model and we found no evidence for the antiprotons from Hawking radiation.
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