On the Origin of Carbon-Based Life

A major breakthrough in research into the creation of elements in the universe was recently made by simulations on JUGENE. Prof. Dr. Ulf-G. Meißner from IAS and IKP at Forschungszentrum Jülich gives a short description of his team's findings:

"Life on earth is based on carbon-12. Carbon is produced in massive, hot stars by the fusion of three alpha particles (helium-4 nuclei). More than 50 years ago, the astronomer Fred Hoyle predicted an excited state of the carbon nucleus with its energy tuned in such a way that a sufficient amount of carbon is generated. This new state was later called the Hoyle state. It was experimentally verified in 1957, but no one had ever been able to reproduce the Hoyle state from scratch, starting from the known interactions of protons and neutrons. This has now changed.

Earlier at IKP and IAS, Evgeny Epelbaum (now at Ruhr University Bochum), Ulf Meißner and collaborators had developed an effective field theory of the nuclear forces that had been successfully tested in few-nucleon systems. In collaboration with Dean Lee from North Carolina State University, they now put six protons and six neutrons on a discretized representation of space-time and calculated the spectrum of carbon-12 using Monte Carlo methods. In order to access the spectrum of carbon-12, they developed a new determinantal projection Monte Carlo scheme. Such an algorithm is ideally suited for JUGENE. The total CPU time used for the Hoyle state calculations was about 4 million CPU hours. Each run used 2048 parallel processors on JUGENE.

The Hoyle state appeared together with other observed states of carbon-12, proving the theory to be correct from first principles. The total disk storage used for the Hoyle state calculations is about 4 terabytes. With these stored configurations, we will now be able to analyse in detail the structure of the Hoyle state, such as its spatial extension or electromagnetic transition strengths. The method paves the way for solving other problems relevant to astrophysics, such as a precise calculation of the cross section of the carbon-12 alpha-particle fusion, which is of prime importance for the generation of oxygen-16."

(Contact: Prof. Dr. Ulf-G. Meißner, meissner@hiskp.uni-bonn.de)

from JSC News No. 195, May 2011