The primordial helium abundance and the number of neutrino families

Peimbert, A. (1), Peimbert, M. (1), and Luridiana, V. (2,3)

(1) Instituto de Astronomía, Universidad Nacional Autónoma de México, México.
(2) Instituto de Astrofísica de Canarias, Spain. (3) Departamento de Astrofísica, Universidad de La Laguna, Spain.

Based on observations of H II regions and the new computations of the recombination coefficients of the He I lines by Porter et al. (2013) we obtain a primordial helium abundance by mass of Yp =0.2446±0.0029. We consider thirteen sources of error for the Yp determination, some of them are mainly due to systematic effects, while the rest are mainly due to statistical effects. We compare our results with other determinations of Yp   present in the literature. Combining our Yp value with computations of primordial nucleosynthesis we find a number of neutrino species Neff =2.90±0.22, and a neutron mean life τν = 872 ± 14 (s).

Article –> http://arxiv.org/abs/1608.02062

 

 

Advertisements
This entry was posted in Atomic data applications, Uncategorized and tagged , . Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s