A POSSIBLE SOLUTION TO THE PROBLEM OF THE GALACTIC EVOLUTION OF D AND HE-3

Light elements, and in particular D and He-3, are commonly used as cosmological probes to obtain bounds on the baryon-to-photon ratio, eta, and to test the predictions of big bang nucleosynthesis. Current models of stellar evolution predict a production of He-3 in stars of low and intermediate mass that, when averaged over the Galactic lifetime, leads to a strong inconsistency between observed and model abundances. In this Letter, we suggest a solution to the problem of the overproduction of He-3 based on nuclear physics. In particular, we consider the effects that a low-energy resonance in the cross section of the He-3 + He-3 reaction has on the stellar yields of stars of different masses. We then follow the evolution of D and He-3 using a model for the chemical evolution of the Galactic disk. We show that, if the energy of the resonance is below E(r) congruent-to 10 keV, an excellent agreement between the solar system data and the model predictions is found. We also derive stringent bounds on eta: 3.5 less-than-or-equal-to less-than-or-equal-to 4.5. Conversely, one can use the observed solar abundances to constrain the resonance properties.