Conveners
Theory
- Osvaldo Civitarese (Department of Physics. University of La Plata.Argentina)
Theory
- Osvaldo Civitarese (Department of Physics. University of La Plata.Argentina)
Theory
- Jouni Suhonen (University of Jyväskylä)
Theory
- Jouni Suhonen (University of Jyväskylä)
Theory
- Javier Menendez (University of Barcelona)
Theory
- Javier Menendez (University of Barcelona)
Theory
- Lukas Graf (University of California, Berkeley)
Theory
- Lukas Graf (University of California, Berkeley)
Neutrinoless double beta decay (NDBD) involves virtual transitions through states of an intermediate nucleus. The wave functions of these states can be efficiently probed by the ordinary muon capture (OMC), a process where a nucleus captures a negative muon from the lowest atomic orbital. The OMC on the NDBD daughter populates the states of the intermediate nucleus of the NDBD, like in the...
The exploration of physics beyond the Standard Model in nuclear physics is closely tied to investigating rare electroweak transitions. The most promising process is neutrinoless double-beta decay ($0\nu\beta\beta$), a nuclear transition where two neutrons simultaneously convert into two protons with the emission of only two electrons. If observed, this second-order decay would prove that...
The kinematic factors in beta and double-beta decays are essential for understanding the decay rates, energy distributions and angular correlations of the emitted leptons, and also represent a testing ground for various BSM effects. Thus, their accurate calculation is very needed as theoretical support for experiments. In my talk I’ll give a review of the present status of these calculations...
The discovery of lepton number violation would be a clear sign of physics beyond the Standard Model, with neutrinoless double beta decay (0νββ) as its most sensitive probe. Within the SMEFT framework, we show that one-loop effects can significantly strengthen tree-level bounds on new-physics scales for several dimension-7 operators across flavours. Using UV model examples, we illustrate the...
The detection of neutrinoless double beta decay (0nbb) remains elusive in spite of the intense experimental efforts to observe it. Indeed, the estimated half-life of the decay depends on nuclear matrix elements (NMEs) which are highly uncertain. A promising avenue to gain insights on the 0nbb NMEs is to explore related second-order processes in the weak (two-neutrino double-beta decay) and...
The addition of two gauge singlet right-handed neutrinos to the Standard Model conveniently explains neutrino oscillations, while also potentially explaining the matter-antimatter asymmetry. The possible Majorana nature of neutrinos resulting from this modification can lead to observable signals in the form of neutrinoless double beta decay. Recent calculations show that the neutrinoless...
The proton-neutron quasiparticle random-phase approximation (QRPA) and the particle number projected QRPA(PQRPA) are used to study the ordinary muon capture (OMC) reaction. In the present work, we have applied both methods to calculate the OMC on the 0$^+$ ground state of $^{76}$Se and $^{136}$Ba and included a comparison with the results obtained in shell model calculations. The nuclei...
The nuclear matrix elements for neutrinoless double-beta decay play an important role in interpreting the experimental half-life limits, yet are hampered by large theoretical uncertainties. One crucial aspect of the uncertainties is the leading-order short-range decay operator identified by the nonrelativistic chiral effective field theory. This short-range operator is required to achieve...
Nuclear matrix elements in double beta decay are crucial for probing the nature of neutrinos. These quantities can, in principle, be inferred from experimental observables through various nuclear reactions. Examples include double charge exchange reactions connecting an initial and a final state, as well as single charge exchange and two-nucleon transfer reactions, which involve multiple...
Double-beta decay provides a promising probe sensitive to physics beyond the Standard Model, especially due to its potential to uncover the Majorana nature of neutrinos. For interpreting data from current and next-generation double-beta decay experiments, including SuperNEMO – which will be capable of measuring not only energy spectra but also angular correlations of emitted electrons – it is...
We calculate the nuclear matrix elements of the neutrinoless and the two-neutrino double-β decays for 136Xe to 136Ba with the higher-order corrections for the transition operators in terms of perturbation interaction. This is a study of the effects that cannot be included in the initial and the final nuclear wave functions. The new terms are derived by an extension of the usual leading-order...
Corrections to neutrinofull double beta decay observables typically focus on QED interactions or on refining the treatment of nuclear matrix elements. We introduce a new kind: chiral. These corrections involve "Yukawa-like" pion exchanges between the two decaying nuclei, as well as weak force magnetism. We explore how these effects alter decay rates and spectra, and whether they can mimic or...
In this presentation, we investigate the electron capture decay of 9797Tc to the 320 keV excited state of 9797Mo, exploring its potential application in neutrino mass determination. We calculate the decay half-life and the energy distribution released following the capture. Due to uncertainties in the angular momentum of the final state, we consider multiple possible transition types. By...
The study of weak interaction nuclear processes in general, and nuclear β-decay in particular, plays a key role in multiple avenues of searches for physics beyond the standard model. The search for the rare neutrinoless double β-decay(0νββ) and exotic dark matter in nuclear laboratory-scale experiments are among such searches that aim to answer foundational questions in physics. In the...
Lepton number violating (LNV) interactions occur in the Standard Model Effective Field Theory (SMEFT) at odd dimensions starting from the dimension-5 Weinberg operator. The operators higher than dimension-5 are suppressed by additional powers of the heavy new scale. However, they can be crucial when traditional seesaw mechanisms leading to tree-level dimension-5 contributions are absent....
The observation of lepton number violation (LNV) would be clear evidence for physics beyond the Standard Model. Famous examples for processes that violate lepton number by two units are neutrino mass mechanisms and neutrinoless double beta decay.
In the Standard Model Effective Field Theory (SMEFT), a ubiquitous framework used for indirect new physics searches, $\Delta L =2$ operators appear...
Two-neutrino double beta decay (2νββ) is a second-order weak-interaction process. Consequently,it is among the rarest radioactive processes observed in nature.
The 2νββ decay has recently attracted significant attention due to substantial investments in the search for the yet unobserved neutrinoless double beta decay (0νββ), a process considered a potential gateway to new physics beyond...
Double beta decay (DBD) is a phenomenon which provides us unique window to physics beyond Standard Model and which lies at the intersection of particle, nuclear and atomic physics. It is of crucial importance to distuinguish whether DBD occurs solely in two-neutrino or also neutrino-less variant. Possible discovery of neutrino-less or other exotic mode of DBD would have big consequences in...
Left-right symmetric model (LRSM) offers rich phenomenon of particle physics. One of which is the neutrinoless double beta decay, besides the light neutrino mass mechanism, it also provide possibilities of other mechanisms. In my talk, I will focus on the mechanism mediated by the light neutrino, and give the corresponding NMEs from two nuclear many-body approaches: Large Scale Shell Model and...
