Primordial nucleosynthesis with massive τ neutrinos.
Abstract
A massive longlived τ neutrino in the MeV regime modifies the primordial lightelement abundances predicted by bigbang nucleosynthesis (BBN) calculations. This effect has been used to derive limits on m_{nu}_{tau}__. Because recently the observational situation has become somewhat confusing and, in part, intrinsically inconsistent, we reconsider the BBN limits on m_{nu}_{tau}__. To this end we use our newly developed BBN code to calculate the primordial abundances as a function of m_{nu}_{tau}__ and of the cosmic baryon density η. We derive concordance regions in the ηm_{nu}_{tau}__plane for several sets of alleged primordial abundances. In some cases a concordance region exists only for a nonvanishing m_{nu}_{tau}__. At the present time BBN does not provide clear evidence for or against a τ neutrino mass.
 Publication:

Astronomy and Astrophysics
 Pub Date:
 November 1997
 DOI:
 10.48550/arXiv.astroph/9612085
 arXiv:
 arXiv:astroph/9612085
 Bibcode:
 1997A&A...327..443R
 Keywords:

 ELEMENTARY PARTICLES;
 NUCLEAR REACTIONS;
 NUCLEOSYNTHESIS;
 ABUNDANCES;
 COSMOLOGY: EARLY UNIVERSE;
 Astrophysics;
 High Energy Physics  Phenomenology
 EPrint:
 10 pages, latexfile, uses laa.sty and psfig.sty, 18 ps figures included