We examine the reach of a Beta-beam experiment with two detectors at carefully chosen baselines for exploring neutrino mass parameters. Locating the source at CERN, the two detectors and baselines are: (a) a 50 kton iron calorimeter (ICAL) at a baseline of around 7150 km which is roughly the magic baseline, e.g., ICAL@INO, and (b) a 50 kton Totally Active Scintillator Detector at a distance of 730 km, e.g., at Gran Sasso. We choose 8B/8Li source ions with a boost factor γof 650 for the magic baseline while for the closer detector we consider 18Ne/6He ions with a range of Lorentz boosts. We find that the locations of the two detectors complement each other leading to an exceptional high sensitivity. With γ=650 for 8B/8Li and γ=575 for 18Ne/6He and total luminosity corresponding to 5 \times (1.1 \times 10^{18}) and 5 \times (2.9 \times 10^{18}) useful ion decays in neutrino and antineutrino modes respectively, we find that our two detector set-up can probe maximal CP violation and establish the neutrino mass ordering if \sin^2 2θ_{13} is 1.4 \times 10^{-4} and 2.7 \times 10^{-4}, respectively, or more. The sensitivity reach for \sin^2 2θ_{13} itself is 5.5 \times 10^{-4}. With a factor of 10 higher luminosity, the corresponding \sin^2 2θ_{13} reach of this set-up would be 1.8 \times 10^{-5}, 4.6 \times 10^{-5} and 5.3 \times 10^{-5} respectively for the above three performance indicators. CP violation can be discovered for 64% of the possible δ_{CP} values for \sin^2 2θ_{13} \geq 10^{-3} ( \geq 8 \times 10^{-5}), for the standard luminosity (10 times enhanced luminosity). Comparable physics performance can be achieved in a set-up where data from CERN to INO@ICAL is combined with that from CERN to the Boulby mine in United Kingdom, a baseline of 1050 km.
英文摘要：
We examine the reach of a Beta-beam experiment with two detectors at carefully chosen baselines for exploring neutrino mass parameters. Locating the source at CERN, the two detectors and baselines are: (a) a 50 kton iron calorimeter (ICAL) at a baseline of around 7150 km which is roughly the magic baseline, e.g., ICAL@INO, and (b) a 50 kton Totally Active Scintillator Detector at a distance of 730 km, e.g., at Gran Sasso. We choose 8B/8Li source ions with a boost factor γof 650 for the magic baseline while for the closer detector we consider 18Ne/6He ions with a range of Lorentz boosts. We find that the locations of the two detectors complement each other leading to an exceptional high sensitivity. With γ=650 for 8B/8Li and γ=575 for 18Ne/6He and total luminosity corresponding to 5\times (1.1 \times 10^{18}) and 5\times (2.9\times 10^{18}) useful ion decays in neutrino and antineutrino modes respectively, we find that our two detector set-up can probe maximal CP violation and establish the neutrino mass ordering if \sin^22θ_{13} is 1.4\times 10^{-4} and 2.7\times 10^{-4}, respectively, or more. The sensitivity reach for \sin^22θ_{13} itself is 5.5 \times 10^{-4}. With a factor of 10 higher luminosity, the corresponding \sin^22θ_{13} reach of this set-up would be 1.8\times 10^{-5}, 4.6\times 10^{-5} and 5.3\times 10^{-5} respectively for the above three performance indicators. CP violation can be discovered for 64% of the possible δ_{CP} values for \sin^22θ_{13} \geq 10^{-3} (\geq 8\times 10^{-5}), for the standard luminosity (10 times enhanced luminosity). Comparable physics performance can be achieved in a set-up where data from CERN to INO@ICAL is combined with that from CERN to the Boulby mine in United Kingdom, a baseline of 1050 km.
Probing Dark Sector Particles Coupling to Neutrinos with Double Beta Decay
UCL（伦敦大学学院）；Instituto de Física Corpuscular, CSIC-Universitat de València（瓦伦西亚大学与西班牙国家研究委员会粒子物理联合研究所）；Institute of Modern Physics, Chinese Academy of Sciences（中国科学院近代物理研究所）；University of Massachusetts（马萨诸塞大学）；Nanjing University of Science & Technology（南京理工大学）
Neutrino Masses, Mixing and Neutrinoless Double-Beta Decay
有效马约拉纳质量的预测|<m>| in neutrinoless double- beta decay in the case of 3-neutrino mixing and massive Majorana neutrinos are reviewed.本文还讨论了寻找无中微子双β衰变和对$|<m>| \gtap 0.01$ eV敏感的实验的物理潜力，以提供关于中微子质量谱类型、中微子质量绝对尺度和PMNS中微子混合矩阵中Majorana CP破坏相的信息。
综述了无中微子双β衰变的研究现状。的努力，以达到所需的灵敏度，以涵盖有效的马约拉纳中微子质量对应的简并和倒置的质量等级。讨论了$0νββ$衰变率与中微子绝对质量标度之间关系的理论（和唯象）问题，特别是$0νββ$衰变的机制问题。最后，描述了中微子磁矩与电荷共轭性质（Dirac vs. Majorana）之间的关系。
