Bound on 3+1 active-sterile neutrino mixing from the first four-week science run of KATRIN
M. Aker, K. Altenmueller, A. Beglarian, J. Behrens, A. Berlev, U. Besserer, B. Bieringer, K. Blaum, F. Block, B. Bornschein, L. Bornschein, M. Boettcher, T. Bru… 展开作者
M. Aker, K. Altenmueller, A. Beglarian, J. Behrens, A. Berlev, U. Besserer, B. Bieringer, K. Blaum, F. Block, B. Bornschein, L. Bornschein, M. Boettcher, T. Brunst, T. S. Caldwell, L. La Cascio, S. Chilingaryan, W. Choi, D. Diaz Barrero, K. Debowski, M. Deffert, M. Descher, P. J. Doe, O. Dragoun, G. Drexlin, S. Dyba, F. Edzards, K. Eitel, E. Ellinger, R. Engel, S. Enomoto, M. Fedkevych A. Felden, J. A. Formaggio, F. M. Fraenkle, G. B. Franklin, F. Friedel, A. Fulst, K. Gauda, W. Gil, F. Glueck, R. Groessle, R. Gumbsheimer, T. Hoehn, V. Hannen, N. Haussmann, K. Helbing, S. Hickford, R. Hiller, D. Hillesheimer, D. Hinz, T. Houdy, A. Huber, A. Jansen, L. Koellenberger, C. Karl, J. Kellerer, L. Kippenbrock, M. Klein, A. Kopmann, M. Korzeczek, A. Kovalik, B. Krasch, H. Krause, T. Lasserre, T. L. Le, O. Lebeda, N. Le Guennic, B. Lehnert, A. Lokhov, J. M. Lopez Poyato, K. Mueller, M. Machatschek, E. Malcherek, M. Mark, A. Marsteller, E. L. Martin, C. Melzer, S. Mertens, S. Niemes, P. Oelpmann, A. Osipowicz, D. S. Parno, A. W. P. Poon, F. Priester, M. Roellig, C. Roettele, O. Rest, R. G. H. Robertson, C. Rodenbeck, M. Rysavy, R. Sack, A. Saenz, A. Schaller, P. Schaefer, L. Schimpf, M. Schloesser, K. Schloesser, L. Schlueter, M. Schrank, B. Schulz, M. Sefcik, H. Seitz-Moskaliuk, V. Sibille, D. Siegmann, M. Slezak, F. Spanier, M. Steidl, M. Sturm, M. Sun, H. H. Telle, T. Thuemmler, L. A. Thorne, N. Titov, I. Tkachev, N. Trost, D. Venos, K. Valerius, A. P. Vizcaya Hernandez, S. Wuestling, M. Weber, C. Weinheimer, C. Weiss, S. Welte, J. Wendel, J. F. Wilkerson, J. Wolf, W. Xu, Y. -R. Yen, S. Zadoroghny, G. Zeller
我们报告了2019年KATRIN实验第一个为期四周的科学运行中的光无菌中微子搜索。用高分辨率MAC-E滤波器分析了高纯度气态分子氚源的β衰变电子，该滤波器在18.57 keV处低于终点40 eV。我们考虑了三个活跃中微子和一个质量为$m_{4}$的不育中微子的框架。该分析是敏感的第四质量状态$m^2_{4} \lesssim$ 1000 eV $^2$和活性到无菌中微子混合到$|U_{e4}|^2 \gtrsim 2\cdot10^{-2}$。未观察到显著的光谱失真，并报告了无菌质量和混合的排除界限。这些新的限制取代美因茨的结果，并提高了$m^2_{4} <$ 30 eV $^2$的Troitsk约束。反应堆和镓异常被限制为$ 100 < Δ{m}^2_{41} < 1000$ eV $^2$。
英文摘要：
We report on the light sterile neutrino search from the first four-week science run of the KATRIN experiment in~2019. Beta-decay electrons from a high-purity gaseous molecular tritium source are analyzed by a high-resolution MAC-E filter down to 40 eV below the endpoint at 18.57 keV. We consider the framework with three active neutrinos and one sterile neutrino of mass $m_{4}$. The analysis is sensitive to a fourth mass state $m^2_{4} \lesssim$ 1000 eV$^2$ and to active-to-sterile neutrino mixing down to $|U_{e4}|^2 \gtrsim 2\cdot10^{-2}$. No significant spectral distortion is observed and exclusion bounds on the sterile mass and mixing are reported. These new limits supersede the Mainz results and improve the Troitsk bound for $m^2_{4} <$ 30 eV$^2$. The reactor and gallium anomalies are constrained for $ 100 < Δ{m}^2_{41} < 1000$ eV$^2$.
KATRIN Sensitivity to keV Sterile Neutrinos with the TRISTAN Detector Upgrade
University of North Carolina, Chapel Hill（北卡罗来纳大学教堂山分校）；Triangle Universities Nuclear Laboratory（三角大学核实验室）；Karlsruhe Institute of Technology (KIT)（卡尔斯鲁厄理工学院）；University of Münster（明斯特大学）；Istituto Nazionale di Fisica Nucleare (INFN) – Sezione di Milano-Bicocca（意大利国家核物理研究所米兰-比科卡分部）
Measurement of the inhomogeneity of the KATRIN tritium source electric potential by high-resolution spectroscopy of conversion electrons from $^{83m}$Kr
最近，巴克桑无菌跃迁实验（BEST）的结果证实了镓异常--在SAGE和GALLEX校准时缺乏电子中微子$ν_e$--统计显著性超过5 $\,σ$。这一结果与镓异常的解释是一致的，即电子中微子振荡成无菌中微子，$ν_s$。在这个解释范围内，BEST实验本身在中微子领域所有先前的异常结果中为不育中微子提供了最强有力的证据。我们结合镓实验的结果与搜索无菌中微子在反应堆反中微子实验（假设CPT守恒的$3+1$中微子部门）。虽然“镓”在模型参数空间中的最佳拟合点（无菌中微子质量平方$m_{ν_s}^2\approx 1.25\,$ eV $^2$，无菌电子中微子混合$\sin^22θ\approx 0.34$）被排除在这些搜索之外，但部分最受欢迎的2 $\,σ$区域与$m^2_{ν_s}>5\,$ eV $^2$是一致的。值得注意的是，NEUTRINO-4实验异常结果所宣扬的区域与BEST实验的区域重叠：联合分析的最佳拟合点是$\sin^22θ\approx 0.38$、$m_{ν_s}^2\approx7.3\,$ eV $^2$，有利区域将由KATRIN实验探索。对BEST结果的无菌中微子解释不仅意味着粒子物理学标准模型的扩展，而且意味着对标准宇宙模型和太阳模型的重大修改，或者对抑制早期宇宙和太阳中无菌中微子产生所需的无菌扇区进行特定修改。
Phasing out of Darkness: From Sterile Neutrino Dark Matter to Neutrino Masses via Time-Dependent Mixing
Max-Planck-Institut für Kernphysik（马克斯·普朗克核物理研究所）；Centro de Astrofísica e Gravitação - CENTRA, Departamento de Física, Instituto Superior Técnico - IST, Universidade de Lisboa - UL（里斯本大学高等技术学院物理系天体物理学与引力中心）；Departamento de Física Teórica and Instituto de Física de Partículas y del Cosmos (IPARCOS-UCM), Universidad Complutense de Madrid（马德里康普顿斯大学理论物理系及粒子与宇宙物理研究所）
Matter Flavor Conversion Mediated by Pseudo-Sterile States as the Possible Origin of Neutrino Oscillation Anomalies
Karlsruher Institut für Technologie (KIT)（卡尔斯鲁厄理工学院）；Dipartimento Interateneo di Fisica “Michelangelo Merlin,”（米开朗基罗·梅林跨大学物理系）；Istituto Nazionale di Fisica Nucleare, Sezione di Bari（意大利国家核物理研究所巴里分部）
