Precision Prediction for the Big-Bang Abundance of Primordial Helium
| dc.creator | Lopez, Robert E. | |
| dc.creator | Turner, Michael S. | |
| dc.date | 1998-07-28 | |
| dc.date | 1999-02-10 | |
| dc.date.accessioned | 2026-07-07T12:01:07Z | |
| dc.date.available | 2026-07-07T12:01:07Z | |
| dc.description | Within the standard models of particle physics and cosmology we have calculated the big-bang prediction for the primordial abundance of \he to a theoretical uncertainty of less than $0.1 \pct$ $(δY_P < \pm 0.0002)$, improving the current theoretical precision by a factor of 10. At this accuracy the uncertainty in the abundance is dominated by the experimental uncertainty in the neutron mean lifetime, $τ_n = 885.4 \pm 2.0 sec$. The following physical effects were included in the calculation: the zero and finite-temperature radiative, Coulomb and finite-nucleon-mass corrections to the weak rates; order-$α$ quantum-electrodynamic correction to the plasma density, electron mass, and neutrino temperature; and incomplete neutrino decoupling. New results for the finite-temperature radiative correction and the QED plasma correction were used. In addition, we wrote a new and independent nucleosynthesis code designed to control numerical errors to be less than 0.1\pct. Our predictions for the \EL[4]{He} abundance are presented in the form of an accurate fitting formula. Summarizing our work in one number, $ Y_P(η= 5\times 10^{-10}) = 0.2462 \pm 0.0004 (expt) \pm < 0.0002 (theory)$. Further, the baryon density inferred from the Burles-Tytler determination of the primordial D abundance, $Ω_B h^2 = 0.019\pm 0.001$, leads to the prediction: $Y_P = 0.2464 \pm 0.0005 (D/H) \pm < 0.0002 (theory) \pm 0.0005 (expt)$. This ``prediction'' and an accurate measurement of the primeval \he abundance will allow an important consistency test of primordial nucleosynthesis. | |
| dc.description | Replaced fitting formulas - new versions differ by small but significant amount. Other minor changes. 30 pages, 17 figures, 5 tables | |
| dc.identifier | https://arxiv.org/abs/astro-ph/9807279 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/9807279 | |
| dc.identifier | Phys.Rev.D59:103502,1999 | |
| dc.identifier | doi:10.1103/PhysRevD.59.103502 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/206998 | |
| dc.subject | Astrophysics | |
| dc.title | Precision Prediction for the Big-Bang Abundance of Primordial Helium | |
| dc.type | text |