J. C. Nzobadila Ondze
A5005002102- Neutrino Physics Research
- Dark Matter and Cosmic Phenomena
- Nuclear physics research studies
- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- Radiation Detection and Scintillator Technologies
- Advanced NMR Techniques and Applications
- Radioactive contamination and transfer
- Atomic and Subatomic Physics Research
- Astronomical and nuclear sciences
- Quantum, superfluid, helium dynamics
- Advanced Chemical Physics Studies
- Nuclear Physics and Applications
- Atmospheric Ozone and Climate
- Mass Spectrometry Techniques and Applications
- Radioactivity and Radon Measurements
- Astrophysics and Cosmic Phenomena
- Radioactive element chemistry and processing
- Particle Detector Development and Performance
University of the Western Cape
2020-2024
Abstract The nEXO neutrinoless double beta (0 νββ ) decay experiment is designed to use a time projection chamber and 5000 kg of isotopically enriched liquid xenon search for the in 136 Xe. Progress detector design, paired with higher fidelity its simulation an advanced data analysis, based on one used final results EXO-200, produce sensitivity prediction that exceeds half-life 10 28 years. Specifically, improvements have been made understanding production scintillation photons charge as...
We used the $^{138}\mathrm{Ba}(d,\ensuremath{\alpha})$ reaction to carry out an in-depth study of states in $^{136}\mathrm{Cs}$, up around 2.5 MeV. In this Letter, we place emphasis on hitherto unobserved below first ${1}^{+}$ level, which are important context solar neutrino and fermionic dark matter (FDM) detection large-scale xenon-based experiments. identify for time candidate metastable would allow a real-time FDM events xenon detectors, with high background suppression. Our results...
We used a high-resolution magnetic spectrograph to study neutron pair-correlated $0^+$ states in $^{136}$Ba, produced via the $^{138}{\rm Ba}(p,t)$ reaction. In conjunction with state-of-the-art shell model calculations, these data benchmark part of dominant Gamow-Teller component nuclear matrix element (NME) for $^{136}$Xe neutrinoless double beta ($0\nu\beta\beta$) decay. demonstrate first time an evaluation $0\nu\beta\beta$ decay NME by use experimental observable, presenting new avenue...
Neutrinoless double beta decay is one of the most sensitive probes for new physics beyond Standard Model particle physics. One isotopes under investigation <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mmultiscripts><a:mi>Xe</a:mi><a:mprescripts/><a:none/><a:mn>136</a:mn></a:mmultiscripts></a:math>, which would into <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mmultiscripts><b:mi>Ba</b:mi><b:mprescripts/><b:none/><b:mn>136</b:mn></b:mmultiscripts></b:math>. Detecting...
Silicon photomultipliers are regarded as a very promising technology for next-generation, cutting-edge detectors low-background experiments in particle physics. This work presents systematic reflectivity studies of Photomultipliers (SiPM) and other samples liquid xenon at vacuum ultraviolet (VUV) wavelengths. A dedicated setup the University Münster has been used that allows to acquire angle-resolved reflection measurements various immersed with 0.45° angular resolution. Four investigated...
Excited states in 98Ru were investigated using γ-ray spectroscopy following the β-decay of 98Rh, and via 100Ru(p,t) reaction. Combining results from two experiments, revised to have spin-parity 4+ subsequently assigned 02+ "γ" bands, respectively. The observed structures are suggested be deformed rotational, rather than spherical vibrational, fit well into systematics these excitations Ru isotopes. excitation is as a shape coexisting configuration. This observation eliminates some last...
We performed a high resolution study of ${0}^{+}$ states in $^{134}\mathrm{Ba}$ using the $^{136}\mathrm{Ba}(p,t)$ two-neutron transfer reaction. Our experiment shows significant portion $L=0$ pair-transfer strength concentrated at excited levels $^{134}\mathrm{Ba}$. Potential implications context $^{136}\mathrm{Xe}\phantom{\rule{4pt}{0ex}}\ensuremath{\rightarrow}\phantom{\rule{4pt}{0ex}}^{136}\mathrm{Ba}$ neutrinoless double beta decay matrix element calculations are briefly discussed.
Electron-neutrino charged-current interactions with xenon nuclei were modeled in the nEXO neutrinoless double-<a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi>β</a:mi></a:math> decay detector (<c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mo>∼</c:mo><c:mn>5</c:mn></c:math> metric ton, 90% <e:math xmlns:e="http://www.w3.org/1998/Math/MathML"...
Background: The $^{136}$Ba isotope is the daughter nucleus in $^{136}$Xe $\beta\beta$ decay. It also lies a shape transitional region of nuclear chart, making it suitable candidate to test variety models. Purpose: To obtain spectroscopic information on states $^{136}$Ba, which will allow better understanding its low-lying structure. These data may prove useful constrain future $\to$ neutrinoless decay matrix element calculations. Methods: A $^{138}\mathrm{Ba}(p,t)$ reaction was used populate...
The isobaric multiplet mass equation (IMME) relates the masses of an isospin quadratically, and it plays important role in studies nuclear structure, astrophysics, fundamental symmetries. This work uses shell-model calculations, together with data from ${}^{32}$Ar $\ensuremath{\beta}$ decay ${}^{32}$S(${}^{3}$He,$t$) experiments to provide step explaining observed IMME violation $A=32$, $T=2$ quintet. It is shown that a small but finite cubic term required for this case due $T=1$ mixing....
The 2019 Mazurian Lakes Conference on Physics was held in Piaski, a vacation resort located at the lake of Bełdany heart Great District, from 1 st to 7 th September 2019.It 36 meeting series initiated over 50 years ago, 1968, by Professor Zdzisław Wilhelmi and his students collaborators.Throughout these years, conferences have gained world-wide reputation for their high scientific merit unique atmosphere.
We used the $^{138}$Ba$(d,α)$ reaction to carry out an in-depth study of states in $^{136}$Cs, up around 2.5~MeV. In this work, we place emphasis on hitherto unobserved below first $1^+$ level, which are important context solar neutrino and fermionic dark matter (FDM) detection large-scale xenon experiments. identify for time candidate metastable would allow a real-time FDM events detectors, with high background suppression. Our results also compared shell-model calculations performed three...
Large-scale low-background detectors are increasingly used in rare-event searches as experimental collaborations push for enhanced sensitivity. However, building such detectors, practice, creates an abundance of radioassay data especially during the conceptual phase experiment when hundreds materials screened radiopurity. A tool is needed to manage and make use screening quantitatively assess detector design options. We have developed a Materials Database Application nEXO serve this purpose....
Abstract As part of a systematic study the nuclear structure Ru isotopes, 98 was investigated via β-decay Rh at iThemba LABS, and 100 Ru( p, t ) reaction Maier-Leibnitz Laboratory. The combined data results in significant revision previous spin assignments clarification nature levels Ru, as well providing insights into evolution structures across isotopic chain.
Background: The nucleosynthesis of several proton-rich nuclei is determined by radiative proton-capture reactions on unstable in nova explosions. One such reaction $^{23}{\rm Mg}(p,\gamma)^{24}{\rm Al}$, which links the NeNa and MgAl cycles oxygen-neon (ONe) novae. Purpose: To extract Al}$ resonance strengths from a study proton-unbound states $^{24}{\rm produced via $^{24}$Mg($^{3}$He,$t$) reaction. Methods: A beam $^3 {\rm He}^{2+}$ ions at 50.7 MeV was used to produce interest $^{24}$Al....
Abstract We study a possible calibration technique for the nEXO experiment using 127 Xe electron capture source. is next-generation search neutrinoless double beta decay (0 νββ ) that will use 5-tonne, monolithic liquid xenon time projection chamber (TPC). The xenon, used both as source and detection medium, be enriched to 90% in 136 Xe. To optimize event reconstruction energy resolution, calibrations are needed map position- time-dependent detector response. 36.3 day half-life of its small...