| タイトル | Big-bang nucleosynthesis revisited |
| 本文（外部サイト） | http://hdl.handle.net/2060/19900013110 |
| 著者（英） | Steigman, Gary; Olive, Keith A.; Walker, Terry P.; Schramm, David N. |
| 著者所属（英） | Fermi National Accelerator Lab. |
| 発行日 | 1989-12-01 |
| 言語 | eng |
| 内容記述 | The homogeneous big-bang nucleosynthesis yields of D, He-3, He-4, and Li-7 are computed taking into account recent measurements of the neutron mean-life as well as updates of several nuclear reaction rates which primarily affect the production of Li-7. The extraction of primordial abundances from observation and the likelihood that the primordial mass fraction of He-4, Y(sub p) is less than or equal to 0.24 are discussed. Using the primordial abundances of D + He-3 and Li-7 we limit the baryon-to-photon ratio (eta in units of 10 exp -10) 2.6 less than or equal to eta(sub 10) less than or equal to 4.3; which we use to argue that baryons contribute between 0.02 and 0.11 to the critical energy density of the universe. An upper limit to Y(sub p) of 0.24 constrains the number of light neutrinos to N(sub nu) less than or equal to 3.4, in excellent agreement with the LEP and SLC collider results. We turn this argument around to show that the collider limit of 3 neutrino species can be used to bound the primordial abundance of He-4: 0.235 less than or equal to Y(sub p) less than or equal to 0.245. |
| NASA分類 | THERMODYNAMICS AND STATISTICAL PHYSICS |
| レポートNO | 90N22426
FERMILAB-PUB-89/262-A
UMN-TH-816/89
NASA-CR-186256
CFA-89-2985
NAS 1.26:186256 |
| 権利 | No Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/137926 |
