论文标题
Canfranc地下实验室的双β衰变实验
Double Beta Decay Experiments at Canfranc Underground Laboratory
论文作者
论文摘要
Canfranc地下实验室（“ LaboratorioSubterráneoDeCanfranc”，LSC）的首次活动始于八十年代中期，位于西班牙比利牛斯山脉下的一条铁路隧道中；从那时起，它已成为一家为地下科学提供不同服务的国际多学科设施。 LSC的研究活动是关于Astroparticle物理学，暗物质搜索和中微子物理学的。而且还进行了核天体物理学，地球物理和生物学的活动。从一开始，对中微子双β衰减的研究一直是LSC的主要研究线之一。在基本中微子特性的表征中，许多未知数仍然存在，并且对这种罕见的衰减过程的研究需要超出标准粒子物理模型的物理学，可以阐明Lepton数量保护，中微子作为Dirac或Majorakana颗粒的性质以及三代质量的绝对尺度以及三代质量的序列。在这里，将在LSC进行的双重β衰减搜索对不同的发射器进行，并遵循不同的实验方法：从实验室的第一个实验中，包括成功的$^{76} $ ge的成功IGEX，该实验对当时的有效中质质量非常严格，到当时的下一个实验，到当前的crure cropteriment $^cerlients $^r-^ - 136 $ xe＆xe everient croptiment（$^）$^{136} $ xe everient（敏感性”）对于$^{130} $ te和$^{100} $ mo，既实施创新的检测技术来区分背景。对于中性双β衰减频道，在90％C.L.中，Igex得出了$^{76} $ ge的半衰期的限制，$ t_ {1/2}^{0ν}^{0ν}> 1.57 \ times 10^{25} $ y，而相应的预期限制为$ t_} $ t_} $ t_} $ {1/2}} $ {1/2}}}^$ {1/2}}^$ {1/2}^0 Net} y对于$^{136} $ Xe从Next-100（暴露于500 kg.y）和$ t_ {1/2}^{0ν}> 2.8 \ times 10^{25} $ y for cross（$ 5 y和4.7 kg of Isotope）。 LSC也已经开发了与其他地下实验室进行的与双重β衰变有关的活动，例如Bipo-3检测器的运行，用于对具有很高敏感性的薄纸的放射性测量。对于这些实验中的每一个，将讨论概念，实验设置和相关结果。
The first activities of the Canfranc Underground Laboratory ("Laboratorio Subterráneo de Canfranc", LSC) started in the mid-eighties in a railway tunnel located under the Spanish Pyrenees; since then, it has become an international multidisciplinary facility equipped with different services for underground science. The research activity at LSC is about Astroparticle Physics, dark matter searches and neutrino Physics; but also activities in Nuclear Astrophysics, Geophysics, and Biology are carried out. The investigation of the neutrinoless double beta decay has been one of the main research lines of LSC since the beginning. Many unknowns remain in the characterization of the basic neutrino properties and the study of this rare decay process requiring Physics beyond the Standard Model of Particle Physics can shed light on the lepton number conservation, the nature of the neutrinos as Dirac or Majorana particles and the absolute scale and ordering of the masses of the three generations. Here, the double beta decay searches performed at LSC for different emitters and following very different experimental approaches will be reviewed: from the very first experiments in the laboratory including the successful IGEX for $^{76}$Ge, which released very stringent limits to the effective neutrino mass at the time, to the present NEXT experiment for $^{136}$Xe and future project CROSS ("Cryogenic Rare-event Observatory with Surface Sensitivity") for $^{130}$Te and $^{100}$Mo, both implementing innovative detector technologies to discriminate backgrounds. For the neutrinoless double beta decay channel and at 90% C.L., IGEX derived a limit to the half-life of $^{76}$Ge of $T_{1/2}^{0ν} > 1.57 \times 10^{25}$ y while the corresponding expected limits are $T_{1/2}^{0ν} > 1.0\times 10^{26}$ y for $^{136}$Xe from NEXT-100 (for an exposure of 500 kg.y) and $T_{1/2}^{0ν} > 2.8 \times 10^{25}$ y for $^{100}$Mo from CROSS (for 5 y and 4.7 kg of isotope). Activities related to double beta decays searches carried out in other underground laboratories have also been developed at LSC and will be presented too, like the operation of the BiPo-3 detector for radiopurity measurements of thin sheets with very high sensitivity. For each one of these experiments, the concept, the experimental set-ups and relevant results will be discussed.
