Conveners
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
- Léonard Imbert (IJClab / CNRS - Université Paris-Saclay)
Theory
- Osvaldo Civitarese (Department of Physics. University of La Plata.Argentina)
Theory
- Osvaldo Civitarese (Department of Physics. University of La Plata.Argentina)
Theory
- Fedor Simkovic (Comenius University and JINR Dubna)
Theory
- Fedor Simkovic (Comenius University and JINR Dubna)
Theory
- Mark Shirchenko (Joint Institute for Nuclear Research)
A new Quantum Field Theory (QFT) formalism for neutrino oscillations in a vacuum is proposed. The neutrino emission and detection are identified with the charged-current vertices of a single second-order Feynman diagram for the underlying process, enclosing neutrino propagation between these two points. The critical point of this approach is the definition of the space-time setup typical for...
TBA
Recently, sensitive experiments operating in frontier muon facilities like MuSEUM (J‐PARC), Mu-MASS (PSI), etc. provide ultra‐high‐precision measurements for quantum electrodynamics (QED) and non-standard (BSM) physics. Historically, the spectroscopy of conventional atoms played essential role in understanding physics (Lamb shift, bound state QED, etc.). However, the proton finite size...
In this talk we are presenting and discussing our results for some
Double Charge Exchange (DCX) systems. The calculations are performed for
light and heavy nuclei participant in the reactions. The microscopic structure
( wave functions and energy spectra) of the light nuclei is given in terms of
shell model results. For the heavy mass partners we use the Quasiparticle Ran-
dom Phase...
The ordinary muon capture (OMC) is a process where a nucleus captures a negative muon from the lowest atomic orbital, the 1s orbital, and modern muon facilities in Japan and Switzerland can produce these muons and shoot them at target atoms. The mass of the captured muon is some 100 MeV, thus introducing momentum exchanges in the range of 100 MeV, in the ballpark of the momentum exchanges...
Ordinary muon capture is a nuclear-weak process in which a negatively charged muon, initially bound on an atomic orbit, is captured by the atomic nucleus, resulting in atomic number reduction by one and emission of a muon neutrino. Thanks to the high momentum transfer involved in the process, it is one of the most promising probes for as yet hypothetical neutrinoless double-beta decay. With...
TBA
We investigate the atomic exchange effect between the final atom's bound electrons and those emitted in the allowed $\beta$ decay and $2\nu\beta\beta$ decay of the initial nucleus. The electron wave functions are obtained with the Dirac-Hartree-Fock-Slater self-consistent method, and we ensure the orthogonality between the continuum and bound electron states of the final atom by modifying the...
Double-beta decay of nuclei, especially neutrinoless double-beta decay, is one of the most intriguing topics in nuclear physics. Observing the neutrinoless double-beta decay would mean physics beyond the standard model. In this presentation, I will cover some of the results of the studies of giant resonances in double-beta decay nuclei and the corresponding daughter nuclei. The strength...
Predictions of neutrinoless double-beta decay (0nbb) nuclear matrix elements are challenging, and markedly differ from each other when different many-body methods are used. One possible avenue to improve this current status is to use data from other observables related to 0nbb to test the theoretical calculations, and to use correlations of these observables with 0nbb matrix elements to...
Calculation of the nuclear matrix elements (NMEs) for double-beta decay is of paramount importance for guiding experiments and for analyzing and interpreting the experimental data, especially for the search of the neutrinoless double beta decay mode (0νββ). However, there are currently still large differences between the NME values calculated by different methods, hence a quantification of...
A qualitative difference in the running sum to the nuclear matrix element of the two-neutrino double-$\beta$ decay of $^{136}$Xe has been found four years ago between QRPA and shell model calculations. The former result has large increase and decrease with respect to the excitation energy of the intermediate state, and the latter one is an almost monotonically and mildly increasing function....
The new particle physics underlying any potential lepton-number-violating signal of neutrinoless double beta decay can be parametrized within the framework of effective field theory in terms of a set of higher-dimensional operators triggering a variety of distinct mechanisms. While it seems to be challenging to unravel the dominant contribution from the observation of this rare nuclear process...
Theoretical research is conducted for interesting isotopes using nuclear shell model to predict level schemes, half-lives, and beta spectral shapes. Further studies of these aspects for isotopes of interest shine a light on different phenomena of such as reactor anti-neutrino anomaly in 92Rb, background effects of beta decays such as 214Pb in Dark Matter experiments, and helping Neutrino's...
Coherent elastic neutrino-nucleus scattering (CEνNS) is a weak neutral current process where the neutrino interacts coherently with the nucleus as a whole. It that has been demonstrated to be a powerful tool to investigate nuclear and electroweak physics since its first observation in 2017 at COHERENT exploiting a CsI detector.
In this presentation, I will present the state-of-the-art results...
Experimental studies of nuclear matrix elements for double beta decays are crucial since theoretically evaluated NMEs are very sensitive to the nuclear models and the nuclear parameters used for the calculations. Single and double charge exchange reactions have been used to study experimentally the GT NMEs associated with DBD NMEs. We show in the present work that M1 and E1 gamma transitions...
A question of high interest is how to relate double charge exchange (DCE) reactions and double beta decay [1-3]. DCE reaction theory predicts two interfering reaction mechanisms, namely second order Double Single Charge Exchange (DSCE) and first order Meson-Nucleon Majorana DCE (MDCE).
The DSCE mechanism is a distorted wave (DW) two-step reaction wher a reaction amplitude is related to the...
The structureless purely leptonic atoms are ideal for testing quantum electrodynamics (QED) and beyond the Standard Model theories (BSM). In recent years, Muonium (Mu) and Positronium (Ps) are considered prominent examples of leptonic atoms that are thoroughly being investigated towards the above aim. A non-relativistic description of leptonic systems provides a simplified quantum mechanical...
In this work, we first formulate the reduced radial Schrödinger equation for a two-leptons system by separating out the center of mass motion. Then, a neural networks technique is, initially, employed to model the numerical solution of the Schrödinger equation written in terms of the relative coordinate r of the two leptons. Next, for the optimization of the defined error function of the...
We offer a comprehensive investigation of electron capture ratios, spanning a wide range of atomic numbers. Our study utilizes a self-consistent computational method that accounts for essential factors such as electron screening, electron correlations, overlap, and exchange corrections, alongside shake-up and shake-off atomic effects.
To compute the electronic wave functions, we employ the...
TBA
We present νDoBe, a Python tool for the computation of neutrinoless double beta decay (0νββ) rates in terms of lepton-number-violating operators in the Standard Model Effective Field Theory (SMEFT). The tool can be used for automated calculations of 0νββ rates, electron spectra and angular correlations for all isotopes of experimental interest, for lepton-number-violating operators up to and...
