Primordial beryllium as a big bang calorimeter
Maxim Pospelov1, Josef Pradler
1Perimeter Institute for Theoretical Physics, Waterloo, Ontario, N2L 2Y5, Canada. pospelov@uvic.ca
Physical Review Letters
|April 27, 2011
Summary
New physics models predict long-lived particles that decay, producing nonthermal energy. This energy can form beryllium-9 (⁹Be), constraining new physics if its abundance is low.
Area of Science:
- Cosmology
- Particle Physics
- Nuclear Astrophysics
Background:
- Models of new physics, including supersymmetry, predict long-lived particles.
- These particles can decay during or after primordial nucleosynthesis, releasing nonthermal energy.
Purpose of the Study:
- To calculate the efficiency of ⁹Be formation from nonthermal energy injection.
- To use the observed ⁹Be abundance as a constraint on new physics models.
Main Methods:
- Simulating nonequilibrium transformations of energy to ⁹Be.
- Analyzing the ⁹Be/H abundance in the context of particle decay scenarios.
Main Results:
- Nonthermal energy injection of O(10 MeV) per baryon at cosmic times of a few hours can create a sizable ⁹Be abundance.
- The absence of a plateau in the ⁹Be/H abundance down to O(10⁻¹⁴) is a key observation.
Conclusions:
- Beryllium-9 (⁹Be) abundance serves as a robust constraint for new physics models involving decaying or annihilating particles.
- The study connects particle physics predictions with cosmological observations of light element abundances.
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