title: Viability of carbon-based life as a function of the light quark mass.
abstract: The Hoyle state plays a crucial role in the helium burning of stars that have reached the red giant stage. The close proximity of this state to the triple-alpha threshold is needed for the production of carbon, oxygen, and other elements necessary for life. We investigate whether this life-essential condition is robust or delicately fine-tuned by measuring its dependence on the fundamental constants of nature, specifically the light quark mass and the strength of the electromagnetic interaction. We show that there exist strong correlations between the alpha-particle binding energy and the various energies relevant to the triple-alpha process. We derive limits on the variation of these fundamental parameters from the requirement that sufficient amounts of carbon and oxygen be generated in stars. We also discuss the implications of our results for an anthropic view of the Universe.
authors.affiliation: Institut für Theoretische Physik II, Ruhr-Universität Bochum, D-44870 Bochum, Germany.
authors.forename: Evgeny
authors.initials: E
authors.lastname: Epelbaum
authors.affiliation: Institut für Theoretische Physik II, Ruhr-Universität Bochum, D-44870 Bochum, Germany.
authors.forename: Hermann
authors.initials: H
authors.lastname: Krebs
authors.affiliation: Institut für Kernphysik, Institute for Advanced Simulation, and Jülich Center for Hadron Physics, Forschungszentrum Jülich, D-52425 Jülich, Germany.
authors.forename: Timo A
authors.initials: TA
authors.lastname: Lähde
authors.affiliation: Department of Physics, North Carolina State University, Raleigh, North Carolina 27695, USA.
authors.forename: Dean
authors.initials: D
authors.lastname: Lee
authors.affiliation: Institut für Kernphysik, Institute for Advanced Simulation, and Jülich Center for Hadron Physics, Forschungszentrum Jülich, D-52425 Jülich, Germany and Helmholtz-Institut für Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Universität Bonn, D-53115 Bonn, Germany and JARA-High Performance Computing, Forschungszentrum Jülich, D-52425 Jülich, Germany.
authors.forename: Ulf-G
authors.initials: UG
authors.lastname: Meissner
mesh_terms: D002244:Carbon; D004601:Elementary Particles; D005118:Extraterrestrial Environment; D008962:Models, Theoretical
chemical_list: D002244:Carbon