MODEL-INDEPENDENT PREDICTIONS OF BIG-BANG NUCLEOSYNTHESIS FROM HE-4 AND LI-7 - CONSISTENCY AND IMPLICATIONS

We examine in detail how BBN theory is constrained, and what predictio ns it can make, when using only the most model-independent observation al constraints. We avoid the uncertainties and model-dependencies that necessarily arise when solar neighborhood D and He-3 abundances are u sed to infer primordial D and He-3 via chemical and stellar evolution models. Instead, we use He-4 and Li-7 thoroughly examining the effects of possible systematic errors in each. Via a likelihood analysis, we find near perfect agreement between BBN theory and the most model-inde pendent data. Given this agreement, we then assume the correctness of BBN to set limits on the single parameter of standard BBN, the baryon- to-photon ratio, and to predict the primordial D and He-3 abundances. For the baryon-to-photon ratio, eta, we find a best value, eta = 1.8 X 10(-10), corresponding to Omega(B)h(2) = 0.0066. We also repeat our a nalysis including recent measurements of D/H from quasar absorption sy stems and find that the near perfect agreement between theory and obse rvation of the three isotopes, D, He-4 and Li-7 is maintained. These r esults have strong implications for the chemical and stellar evolution of the light elements, in particular for He-3. In addition, our resul ts (especially if the D/H measurements are confirmed) have implication s for the stellar depletion of Li-7. Finally, we set limits on the num ber N-nu of neutrino flavors, using an analysis which carefully and sy stematically includes all available experimental constraints. The valu e N-nu=3.0 its best with BBN and a 95% CL upper limit of N(nu)less tha n or similar to 4 is established.