Related papers: Double beta decay to the excited states: experimen…
Nuclear double-beta decays are a unique probe to search for new physics beyond the Standard Model. Still-unknown particles, non-standard interactions, or the violation of fundamental symmetries would affect the decay kinematic, creating…
We construct two new classes of models for double beta decay, each of which leads to an electron spectrum which differs from the decays which are usually considered. One of the classes has a spectrum which has not been considered to date,…
Studying the excited states of doublets is challenging for their typically multiconfigurational character. We employ light-scanning-tunneling microscopy (light-STM) to investigate photon-induced currents on a single open-shell PTCDA anion…
The last decades brought an impressive progress in synthesizing and studying properties of nuclides located very far from the beta stability line. Among the most fundamental properties of such exotic nuclides, usually established first, is…
For well over half a century, precision studies of neutron and nuclear $\beta$ decays have been at the forefront of searches for exotic electroweak physics. Recent advances in nuclear ab initio theory and the widespread use of effective…
An exactly solvable model for a description of the two-neutrino double beta decay transition of the Fermi type is considered. By using perturbation theory an explicit dependence of the two-neutrino double beta decay matrix element on the…
In a sample of 6.6 million produced B mesons we have observed decays B -> eta' K, with branching fractions BR(B+ -> eta' K+ = 6.5 +1.5 -1.4 +- 0.9) x $10^{-5}$ and BR(B0 -> eta' K0 = 4.7 +2.7 -2.0 +- 0.9) x $10^{-5}$. We have searched with…
Within the DWBA framework, we develop a theoretical description of single and double heavy ion charge exchange (CE) reactions. We show that absorption effects are particularly important for heavy ion reactions, leading to a noticeable…
A search for alpha and double beta decays of ytterbium isotopes was performed with an ultra-low background high purity germanium detector at Gran Sasso Underground Laboratory (Italy). A 194.7 g Yb$_2$(C$_2$O$_4$)$_3$ powder sample was…
A schematic study of the $\beta \beta 2\nu $-decay of $^{48}Ca$ is made in a shell-model approach. The emphasis is especially put on the role of the spin-orbit potential in relation with the contribution of other terms in the strong…
In the framework of the two-group configuration model we obtain formulas for the reduced transition rates for beta- and gamma-transitions in even-even, odd-odd, even-odd, and odd-even nuclei. We explored dependencies of the transition rates…
We investigate nuclear-resonant electron scattering as occurring in the two-step process of nuclear excitation by electron capture (NEEC) followed by internal conversion. The nuclear excitation and decay are treated by a phenomenological…
We study neutrinoless double-beta decay in an effective field theory (EFT) for heavy nuclei, which are treated as a spherical core coupled to additional neutrons and/or protons. Since the low-energy constants of the EFT cannot be fitted to…
We optically probe the spectrum of ground and excited state transitions of an individual, electrically tunable self-assembled quantum dot molecule. Photocurrent absorption measurements show that the spatially direct neutral exciton…
The resonance strength of the two-step process of nuclear excitation by electron capture followed by $\gamma$ decay of the nucleus can be significantly increased in highly charged ions if the resonant capture proceeds via an excited…
Limits on $\beta^+$EC (here EC denotes electron capture) and ECEC processes in $^{112}$Sn have been obtained using a 380 cm$^3$ HPGe detector and an external source consisting of 53.355 g enriched tin (94.32% of $^{112}$Sn). A limit with…
Weak-interaction rates, including beta-decay and electron capture, are studied in several odd-A nuclei in the pf-shell region at various densities and temperatures of astrophysical interest. Special attention is paid to the relative…
Comprehensive description of the phenomenology of the $\beta\beta$ decay is given, with emphasis on the nuclear physics aspects. After a brief review of the neutrino oscillation results and of motivation to test the lepton number…
A theoretical analysis of the single-state dominance hypothesis for the two-neutrino double-beta decay rates is performed on the examples of the double-beta decays of 100Mo, 116Cd, and 128Te. We also test the validity of an extended…
Recent progress in nuclear-structure theory has been dramatic. I describe recent and future applications of ab initio calculations and the generator coordinate method to double-beta decay. I also briefly discuss the old and vexing problem…