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 Cryogenic Underground Observatory for Rare Events (CUORE) is the first bolometric experiment searching for 0νββ decay that has successfully reached the one-tonne mass scale. The detector, located at the LNGS in Italy, consists of an array of 988 TeO$_2$ crystals arranged in a compact cylindrical structure of 19 towers. CUORE has been collecting data continuously at ~10 mK since 2017,...
A low-background experiment to study double-beta decay processes in $^{106}$Cd using a $^{106}$CdWO$_4$ crystal scintillator (mass 215.4 g) enriched in $^{106}$Cd to 66$\%$, has been performed at the National Laboratories of Gran Sasso (LNGS), in Italy. Events in the $^{106}$CdWO$_4$ detector are recorded in (anti)coincidence with two large-volume CdWO$_4$ scintillation counters. The setup,...
The Global Rare Anomalous Nuclear Decay Experiment (GRANDE) aims to push the frontiers of nuclear and particle physics by investigating rare nuclear decay processes. A key focus of GRANDE is the measurement of extremely rare nuclear transitions and the search for exotic dark matter particles, including axion-like particles, anapole dark matter, and dark photons in nuclear transitions. Based on...
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...
Positron-emitting double beta decay modes are rare nuclear processes. Their detection is challenging due to extremely low decay probabilities, complex experimental signatures, and the low natural abundance of suitable isotopes. Studying these decays can offer valuable insights into nuclear structure and fundamental symmetries. The decay rate is influenced by nuclear matrix elements (NMEs) and...
One of the most puzzling open questions in physics is whether neutrinos are their own antiparticles - are they Majorana particles? Demonstrating this property would impact our understanding of the neutrino mass ordering and the matter-antimatter asymmetry in the Universe. The Large Enriched Germanium Experiment for Neutrinoless $\beta\beta$ Decay (LEGEND) aims to shed light on this puzzle by...
Neutrinoless double-beta decay (0νββ) is a key process addressing some of the most significant open questions in particle physics, the conservation of lepton number and the Majorana nature of the neutrino. Over the past decades, extensive efforts have been dedicated to improving the sensitivity of 0νββ half-life measurements across multiple isotopes. The next generation of experiments aims to...
The 3dSPARK (3D-Printed Scintillating Polymer Assembly for Rare Events at milliKelvin Temperature) project aims to develop a novel type of assembly for next-generation bolometric neutrinoless double beta decay experiments. A significant part of the background in bolometric experiments originates from contamination of the copper frames traditionally used in the assembly. By using a 3D-printed...
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...
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...
The LEGEND experiment has been designed to search for neutrinoless double-beta decay in Ge-76. Its discovery would have profound implications for neutrino physics and cosmology providing unambiguous evidence for the Majorana nature of neutrinos, lepton number non-conservation and the absolute neutrino mass scale. The LEGEND-1000 detector represents the ton-scale phase of the LEGEND program,...
The search for double beta decay of $^{150}$Nd to the excited levels of $^{150}$Sm was performed at the Gran Sasso underground laboratory of INFN (Italy) with a four-crystal HPGe gamma spectrometer over 5.845 yr by using a highly purified neodymium-containing sample. The two-neutrino double beta transition of $^{150}$Nd to the first 740.5 keV $0^+$ level of $^{150}$Sm was detected in both...
Gadolinium-160 ($^{160}$Gd) is a candidate for double beta decay with relatively high natural abundance (21.9%). However, its low Q-value (1.73 MeV) makes the observation of even the two-neutrino double beta decay (2$\nu$2$\beta$) extremely challenging. Previous experiments using a 2-inch Gd$_2$SiO$_5$ (GSO) scintillator couldn’t detect 2$\nu$2$\beta$ due to significant background from...
MONUMENT (Muon Ordinary capture for NUclear Matrix element) measures Ordinary Muon Capture (OMC) on isotopes relevant for the neutrinoless double beta (0nbb) decay searches. OMC is a powerful tool to study the $0\nu\beta\beta$-decay NMEs as it involves similar momentum transfer and allows to experimentally probe the intermediate virtual transitions involved in the decay. OMC on $^A_{Z+2}X$...
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...
At present, there is limited experimental data on low-energy inelastic neutrino scattering on nuclei. For neutrino energies below 100 MeV, measurements are available only for a few nuclear targets. The analysis of these data strongly depends on the structure of the charge-exchange strength function, which characterizes the intensity of transitions in the final nucleus as a function of...
The 2nd isomeric state of 178Hf has high energy of 2.446 MeV and big half-life of 31 yr. Normally it decays spontaneously to the ground state of 178Hf by isomeric transition with emission of cascade of gamma quanta with energies up to ~600 keV. Possible interactions of 178m2Hf with some given inelastic Dark Matter (iDM) candidates could lead to emission of gammas with energies >1 MeV from the...
The RES-NOVA project detects cosmic neutrinos via coherent elastic neutrino-nucleus scattering (CEνNS) using archaeological Pb-containing PbWO4 cryogenic detectors. RES-NOVA plans to conduct a direct detection campaign while waiting for neutrinos of astrophysical origin. The natural abundance of Pb-207 offers sensitivity to spin-dependent dark matter interactions. Additionally, Effective Field...
The KIMS collaboration had reported that a lower limit on the Sn-124 half-life using an organotin-loaded liquid scintillation detector remained the best result. And recent results from other experiments calls that the next generation of neutrinoless double beta decay experiment requires a substantial quantity of target isotope in order to attain the enhanced sensitivity of 1E28 year....
PandaX-4T is a liquid xenon time projection chamber (TPC) that searches for dark matter particles and neutrinoless double beta decay of xenon isotopes. In this talk, I will present our latest work on the double beta decay half-life limit established by PadnaX-4T for Xe-136(-134), as well as the effort to utilize the spectral information of Xe-136 decay for NME and new physics analysis.
Despite significant research efforts, the precise measurements of certain radioactive decays remain elusive. In this study, we have measured the energy and decay time of Ac-228 isomers produced by the beta decay of Ra-228. This was achieved using a novel method where a Ra-228 radioactive source is deposited in a scintillator. Given the low energy (45.8 keV) Q value of Ra-228 beta decay and the...
The SuperNEMO Experiment has entered its physics data-taking phase as of April 2025, becoming the only operational double beta decay detector capable of full topological event reconstruction via the tracker-calorimeter design. This topology-driven approach provides powerful discrimination of signal and background, and is uniquely suited to explore a wide range of BSM scenarios. The detector,...
Modern bubble chambers offer a unique opportunity to probe the dark matter parameter space. These detectors use superheated fluids such as C₃F₈ to detect elastic scatters on target nuclei. Nuclear recoils that deposit energy above the detector’s thermodynamic threshold—set by its operating temperature and pressure—nucleate visible bubbles, which are recorded by high-speed cameras.
The PICO...
