Abstract
We study the finite temperature and density effects on beta decay rates to compute their contributions to nucleosynthesis. QED type corrections to beta decay from the hot and dense background are estimated in terms of the statistical corrections to the self-mass of an electron. For this purpose, we re-examine the hot and dense background contributions to the electron mass and compute its effect to the beta decay rate, helium yield, energy density of the universe as well as the change in neutrino temperature from the first order contribution to the self-mass of electrons during these processes. We explicitly show that the thermal contribution to the helium abundance at T = m of a cooling universe 0.045 % is higher than the corresponding contribution to helium abundance of a heating universe 0.031% due to the existence of hot fermions before the beginning of nucleosynthesis and their absence after the nucleosynthesis, in the early universe. Thermal contribution to helium abundance was a simple quadratic function of temperature, before and after the nucleosynthesis. However, this quadratic behavior was not the same before the decoupling temperature due to weak interactions; so the nucleosynthesis did not even start before the universe had cooled down to the neutrino decoupling temperatures and QED became a dominant theory. It is also explicitly shown that the chemical potential in the core of supermassive and superdense stars affect beta decay and their helium abundance but the background contributions depend on the ratio between temperature and chemical potential and not the chemical potential or temperature only. It has been noticed that temperature plays a role of regulating parameter in an extremely dense systems.
Highlights
Primordial nucleosynthesis was facilitated by means of beta decay processes
When nuclear formation takes place inside a hot and dense medium, nucleosynthesis parameters are affected by the finite temperature and density (FTD) of the background due to the modifications in the beta decay rates in a statistical medium
Beta decay rates are pronounced in a different manner; they contributed differently to primordial nucleosynthesis in the early universe and inside hot and dense stellar cores because of the difference in the corresponding medium properties
Summary
Primordial nucleosynthesis was facilitated by means of beta decay processes. When nuclear formation takes place inside a hot and dense medium, nucleosynthesis parameters are affected by the finite temperature and density (FTD) of the background due to the modifications in the beta decay rates in a statistical medium. Beta decay rates are pronounced in a different manner; they contributed differently to primordial nucleosynthesis in the early universe and inside hot and dense stellar cores because of the difference in the corresponding medium properties. In this paper we just restrict ourselves to the standard electroweak model with the massless neutrino and exclusively study the QED type FTD corrections [16]-[30] only For this purpose, we consider previously calculated relationships of electron mass with nucleosynthesis parameters, such as beta decay rate and helium abundance in the early universe [1]-[3]. The most general calculations of the first order thermal loop corrections to electron self-mass, charge and wave function are performed in detail, incorporating the background density effects through the chemical potential [27]-[30]. High abundance of helium at high density and low temperature, in the presence of strong magnetic fields may provide favorable conditions for super fluidity
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
