Neutrino mixing in nuclear rapid neutron-capture processes

Abstract

<jats:p> A possible mechanism for the formation of heavy-mass elements in supernovae is the rapid neutron-capture-mechanism ([Formula: see text]-process). It depends upon the electron-fraction [Formula: see text], a quantity which is determined by beta-decay-rates. In this paper, we focus on the calculation of electroweak decay-rates in presence of massive neutrinos. The resulting expressions are then used to calculate nuclear reactions entering the rapid-neutron capture. We fix the astrophysical parameters to the case of a core-collapse supernova. The neutrino sector includes a mass scheme and mixing angles for active neutrinos, and also by including the mixing between active and sterile neutrinos. The results of the calculations show that the predicted abundances of heavy-mass nuclei are indeed affected by the neutrino mixing. </jats:p>

Limits on active-sterile neutrino mixing parameters using heavy nuclei abundances

“…p mn, and λ is the weak coupling constant defined as the ratio of the axial vector and vector coupling constant. 32 The calculated neutron-decay-rate depends strongly on the mixing angle θ 14 , and weakly on the masssquare difference ∆m 2 14 (see 39 for details). We worked in the 2 + 1 scheme and assumed normal-mass-hierarchy for the neutrino-mass eigenstates, 40…”

“…The parameters for the sterile neutrino sector θ 14 (mixing angle) and ∆m 2 14 (difference a There is a misprint in the definition of the factor D j given in ref. 39 Therein mn → m 3 n in the denominator, and ξ j → ξ 2 j in the expression of Γ 0 β given in the same reference.…”