A study of neutrinoless double electron capture in $^{40}$Ca from the AMoRE experiment
AMoRE Collaboration, A. Agrawal, V. V. Alenkov, P. Aryal, J. Beyer, B. Bhandari, R. S. Boiko, K. Boonin, O. Buzanov, C. R. Byeon, N. Chanthima, M. K. Cheoun, J.… 展开作者
AMoRE Collaboration, A. Agrawal, V. V. Alenkov, P. Aryal, J. Beyer, B. Bhandari, R. S. Boiko, K. Boonin, O. Buzanov, C. R. Byeon, N. Chanthima, M. K. Cheoun, J. S. Choe, Seonho Choi, S. Choudhury, J. S. Chung, F. A. Danevich, M. Djamal, D. Drung, C. Enss, A. Fleischmann, A. M. Gangapshev, L. Gastaldo, Y. M. Gavrilyuk, A. M. Gezhaev, O. Gileva, V. D. Grigorieva, V. I. Gurentsov, C. Ha, D. H. Ha, E. J. Ha, D. H. Hwang, E. J. Jeon, J. A. Jeon, H. S. Jo, J. Kaewkhao, C. S. Kang, W. G. Kang, V. V. Kazalov, S. Kempf, A. Khan, S. Khan, D. Y. Kim, G. W. Kim, H. B. Kim, Ho-Jong Kim, H. J. Kim, H. L. Kim, H. S. Kim, M. B. Kim, S. C. Kim, S. K. Kim, S. R. Kim, W. T. Kim, Y. D. Kim, Y. H. Kim, K. Kirdsiri, Y. J. Ko, V. V. Kobychev, V. Kornoukhov, V. V. Kuzminov, D. H. Kwon, C. H. Lee, DongYeup Lee, E. K. Lee, H. J. Lee, H. S. Lee, J. Lee, J. Y. Lee, K. B. Lee, M. H. Lee, M. K. Lee, S. W. Lee, Y. C. Lee, D. S. Leonard, H. S. Lim, B. Mailyan, E. P. Makarov, P. B. Nyanda, Y. Oh, S. L. Olsen, S. I. Panasenko, H. K. Park, H. S. Park, K. S. Park, S. Y. Park, O. G. Polischuk, H. Prihtiadi, S. Ra, S. S. Ratkevich, G. Rooh, E. Sala, M. B. Sari, J. Seo, K. M. Seo, B. Sharma, K. A. Shin, V. N. Shlegel, K. Siyeon, J. So, N. V. Sokur, J. K. Son, J. W. Song, N. Srisittipokakun, V. I. Tretyak, R. Wirawan, K. R. Woo, H. J. Yeon, Y. S. Yoon, Q. Yue
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.
Measurement of the Background Activities of a 100Mo-enriched Powder Sample for an AMoRE Crystal Material by using Fourteen High-Purity Germanium Detectors
A feasibility study of extruded plastic scintillator embedding WLS fiber for AMoRE-II muon veto
AMoRE-II是高级钼基稀有过程实验的第二阶段，目的是使用约200公斤含氘低温探测器寻找100 Mo同位素的无中微子双β衰变。AMoRE-II需要使用各种方法将本底水平保持在10-5计数/keV/kg/年以下，以最大限度地提高灵敏度。方法之一是在远离宇宙射线背景的地下深处进行实验。AmoRE-II将在Yemilab运行，深度约为1，000米。然而，即使在如此深的地下环境中，仍然存在幸存的宇宙μ子，它们会影响测量，应尽可能排除。μ子否决探测器是必要的，以拒绝μ子诱导的粒子进入内部探测器，其中低温探测器位于。我们已经研究了使用挤出塑料闪烁体和波长漂移光纤与SiPM一起作为μ子否决系统的可能性。我们发现最佳的结构是两层塑料分离器（PS，150 cm x 25 cm x 1.2 cm），每个槽有两个WLS光纤，它可以很好地分离放射性γ，μ子探测效率在99.4%以上。基于700米深地下原型测量的预期通量，我们发现，在Yemilab的AMoRE-II的μ子否决系统的死时间为1 ms否决窗口的0.6%的整个μ子事件。
Ab initio studies of double Gamow-Teller transition and its correlation with neutrinoless double beta decay
利用手征相互作用和几种{ \em ab initio}方法计算了一系列同位素基态到基态的双Gamow-Teller跃迁的核矩阵元，并探讨了这些核矩阵元与轻Majorana中微子交换产生的无中微子双β衰变的核矩阵元之间的相关性.当我们考虑了{ \em ab initio}计算的所有同位旋守恒跃迁和同位旋变化跃迁的NME时，我们得到了很强的相关性.然而，对于实验相关的同位旋变化跃迁本身，相关性较弱，可能无助于减少无中微子双β衰变的NME的不确定性。
