The mass-hierarchy and CP-violation discovery reach of the LBNO long-baseline neutrino experiment
The mass-hierarchy and CP-violation discovery reach of the LBNO long-baseline neutrino experiment
复制标题
DOI：
10.1007/jhep05(2014)094
复制
发表时间：
2014-05-21
影响因子：
5.4
通讯作者：
Zito, M.
中科院分区：
文献类型：
--
作者：
Agarwalla, S. K.;Agostino, L.;Zito, M.
由LBNO合作提出的下一代中微子天文台将解决粒子和天体粒子物理学中的基本问题。实验由远端探测器和近端探测器组成。远端探测器的第一阶段是20 kt的双相TPC和磁化铁量热计，位于距离欧洲核子研究中心2300公里的地方，近端探测器基于高压氩气TPC。长基线提供了一个独特的机会来研究中微子风味振荡在它们的第一次和第二次振荡最大值，探索L/E行为，并区分delta（CP）和物质产生的影响。在本文中，我们重新评估了该装置在确定质量层次（MH）和发现cp违和（CPV）方面的物理潜力，使用来自CERN SPS的功率为750千瓦的常规中微子束。我们对振荡参数先验和系统不确定性的知识采用保守假设。给出了各系统误差对振荡先验精度的影响。我们证明了LBNO的第一阶段可以明确地确定整个相空间的MH到bb50 σ C.L.。我们表明实验的统计处理非常重要，从而得出LBNO在最多4-5年的运行中具有接近100%的概率确定MH的结论。由于MH的知识对于从数据中提取δ (CP)是必不可少的，所以LBNO的第一个阶段可以令人信服地利用今天关于振荡参数的知识和对系统不确定性的现实假设，为3 σ c.l的CPV提供证据。
The next generation neutrino observatory proposed by the LBNO collaboration will address fundamental questions in particle and astroparticle physics. The experiment consists of a far detector, in its first stage a 20 kt LAr double phase TPC and a magnetised iron calorimeter, situated at 2300 km from CERN and a near detector based on a highpressure argon gas TPC. The long baseline provides a unique opportunity to study neutrino flavour oscillations over their 1st and 2nd oscillation maxima exploring the L/E behaviour, and distinguishing effects arising from delta(CP) and matter.In this paper we have reevaluated the physics potential of this setup for determining the mass hierarchy (MH) and discovering CP-violation (CPV), using a conventional neutrino beam from the CERN SPS with a power of 750 kW. We use conservative assumptions on the knowledge of oscillation parameter priors and systematic uncertainties. The impact of each systematic error and the precision of oscillation prior is shown. We demonstrate that the first stage of LBNO can determine unambiguously the MH to > 5 sigma C.L. over the whole phase space. We show that the statistical treatment of the experiment is of very high importance, resulting in the conclusion that LBNO has similar to 100% probability to determine the MH in at most 4-5 years of running. Since the knowledge of MH is indispensable to extract delta(CP) from the data, the first LBNO phase can convincingly give evidence for CPV on the 3 sigma C.L. using today's knowledge on oscillation parameters and realistic assumptions on the systematic uncertainties.