arXiv subjects

P. B. Nyanda

Publications and source records attributed to P. B. Nyanda.

3 recordsLinked to original sources

arXiv2026

A study of neutrinoless double electron capture in $^{40}$Ca from the AMoRE experiment

The search for neutrinoless double electron capture ($0ν\mathrm{2EC}$) provides a sensitive probe of lepton-number violation and the Majorana nature of neutrinos. We investigate the $0ν\mathrm{2EC}$ decay of $^{40}$Ca using cryogenic detectors equipped with metallic magnetic calorimeters in the AMoRE-I experiment. The analysis is based on a physics dataset corresponding to a total exposure of 7.32 kg$\cdot$yr from thirteen $^{40}$Ca$^{100}$MoO$_4$ crystals. No significant excess is observed, and a lower limit on the half-life is obtained as $T^{0ν}_{1/2} > 1.7 \times 10^{22}$ yr at 90$\%$ confidence level. An improved sensitivity is expected for the upcoming AMoRE-II experiment. These results demonstrate the potential of CaMoO$_4$ detectors to explore rare decay processes beyond the primary $^{100}$Mo $0νββ$ search program.

nucl-ex↗

arXiv2022

Status and performance of the AMoRE-I experiment on neutrinoless double beta decay

AMoRE is an international project to search for the neutrinoless double beta decay of $^{100}$Mo using a detection technology consisting of magnetic microcalorimeters (MMCs) and molybdenum-based scintillating crystals. Data collection has begun for the current AMORE-I phase of the project, an upgrade from the previous pilot phase. AMoRE-I employs thirteen $^\mathrm{48depl.}$Ca$^{100}$MoO$_4$ crystals and five Li$_2$$^{100}$MoO$_4$ crystals for a total crystal mass of 6.2 kg. Each detector module contains a scintillating crystal with two MMC channels for heat and light detection. We report the present status of the experiment and the performance of the detector modules.

physics.ins-det↗

arXiv2022

A feasibility study of extruded plastic scintillator embedding WLS fiber for AMoRE-II muon veto

AMoRE-II is the second phase of the Advanced Molybdenum-based Rare process Experiment aiming to search for the neutrino-less double beta decay of 100Mo isotopes using ~ 200 kg of molybdenum-containing cryogenic detectors. The AMoRE-II needs to keep the background level below 10-5 counts/keV/kg/year with various methods to maximize the sensitivity. One of the methods is to have the experiment be carried out deep underground free from the cosmic ray backgrounds. The AMoRE-II will run at Yemilab with ~ 1,000 m depth. However, even in such a deep underground environment, there are still survived cosmic muons, which can affect the measurement and should be excluded as much as possible. A muon veto detector is necessary to reject muon-induced particles coming to the inner detector where the molybdate cryogenic detectors are located. We have studied the possibility of using an extruded plastic scintillator and wavelength shifting fiber together with SiPM as a muon veto system. We found that the best configuration is two layers of plastic scintillators (PSs, 150 cm x 25 cm x 1.2 cm) with two WLS fibers per groove, which could separate radiogenic gammas well with muon detection efficiency above 99.4% along the length of the PS. Based on the expected flux from a prototype measurement at a 700 m deep underground, we found that the dead time of the muon veto system for AMoRE-II at the Yemilab with a 1 ms veto window is 0.6% of whole muon events.

physics.ins-det↗