Predictions on double
beta decay mediated by light singlet fermions in the [W.sub.L] - [W.sub.L] channel are discussed in Section 6 where we have given its mass limits from the existing experimental data.
This pathway to the creation of heavier and heavier nuclei is called the s -process, since the rate of neutron capture is slow compared to the rate of
beta decay. Accordingly, atoms synthesized via this mechanism are called s-process elements.
Vogel, "Double
beta decay," Annual Review of Nuclear and Particle Science, vol.
In order to improve the determination of |[V.sub.ud]| beyond the precision of obtained from the above systems, one can study the neutron
beta decay. An advantage of the study of the neutron system is the relatively stronger understanding of the necessary corrections.
Most important for the neutrinoless double
beta decay are the decays of [sup.68]Ge and [sup.60]Co since Q values above [Q.sub.[beta][beta]] = 2039 keV occur in the chain, and the lifetimes are in the range of years.
Key words:
beta decay; CP-violation; physics beyond the Standard Model; time-reversal violation.
Back around 1930, difficulties in balancingenergy in
beta decay of atomic nuclei led Wolfgang Pauli to postulate the existence of a subatomic particle that had no rest mass, which Enrico Fermi named "little neutral one' or neutrino.
de Fatis, "Cerenkov emission as a positive tag of double
beta decays in bolometric experiments," European Physical Journal C, vol.
A false asymmetry associated with the correlation [s.sub.n] * [k.sub.[beta]] in neutron
beta decay, where [k.sub.[beta]] is the propagation direction of the beta particle, is reduced by the fraction of neutrons that decay in the target ([10.sup.-7]) and the fractional gamma yield for a typical electron from the decay, yielding an estimate for the false asymmetry below [10.sup.-12].
In the following sections we discuss the observable signatures of these coefficients for Lorentz violation in different types of neutrino experiments including oscillations, neutrino velocity, and
beta decays.
Outside of a nucleus, however, free neutrons last only about 10 minutes before disintegrating by means of
beta decay.