2 research outputs found
Helium and Deuterium Abundances as a Test for the Time Variation of the Fine Structure Constant and the Higgs Vacuum Expectation Value
We use the semi-analytic method of \citet{Esma91} to calculate the abundances
of Helium and Deuterium produced during Big Bang nucleosynthesis assuming the
fine structure constant and the Higgs vacuum expectation value may vary in
time. We analyze the dependence on the fundamental constants of the nucleon
mass, nuclear binding energies and cross sections involved in the calculation
of the abundances. Unlike previous works, we do not assume the chiral limit of
QCD. Rather, we take into account the quark masses and consider the one-pion
exchange potential, within perturbation theory, for the proton-neutron
scattering. However, we do not consider the time variation of the strong
interactions scale but attribute the changes in the quark masses to the
temporal variation of the Higgs vacuum expectation value. Using the
observational data of the helium and deuterium, we put constraints on the
variation of the fundamental constants between the time of nucleosynthesis and
the present time.Comment: 27 pages, 1 figure, replaced to match published version, new
references adde
Possible variations of the fine structure constant and their metrological significance
We briefly review the recent experimental results on possible variations of
the fine structure constant on the cosmological time scale and its
position dependence. We outline the theoretical grounds for the assumption that
might be variable, mention some phenomenological models incorporating
a variable into the context of modern cosmology and discuss the
significance of possible variations for theoretical and practical
metrology.Comment: Latex, 17 pages, brief review. References updated, minor errors
remove