Numbers of accelerator and reactor neutrino oscillation experiments aiming to search finite value of $θ_{13}$ are starting within a few years. T2K experiment is a next generation long baseline neutrino experiment starts on 2009, in Japan. A main goal of the T2K experiment is to discover a finite $θ_{13}$ by observing $ν_e$ appearance. Determining $θ_{13}$ leads a next search of CP violation in the lepton sector. Status of T2K experiment and prospects for CP measurement are reported in the report.
We revisit correlations of neutrino oscillation parameters in reactor and long-baseline neutrino oscillation experiments. A framework based on an effective value of $θ_{13}$ is presented, which can easily reproduce experimental results. It also clarifies why current and future long-baseline experiments will have less precision on values around $δ_{CP} = \pm π/2$ than on values around $δ_{CP} = 0$. Optimization potential for the determination of the theoretically very interesting values around $δ_{CP} = -π/2$ is also pointed out, which would require that future runs of accelerator experiments a…
对基于加速器的聚变堆进行了可行性研究。我们考虑了一种新的方案,从加速器的光束击中目标等离子体的聚变反应的共振,并建立一个可行的反应堆的特征标准。在本研究中,我们考虑反应$ d + t \rightarrow n + α, d + {}^3H_e \rightarrow p + α$和$p + {}^{11}B \rightarrow 3 α$。等离子体的临界温度是由聚变能量增益克服束流的阻止本领确定的。所需的等离子体寿命由共振宽度、束流速度和等离子体密度确定。我们估计的临界束流通量的平衡对等离子体的热能和损失,由于停止功率的情况下,惰性等离子体的聚变生产的能量。临界通量与等离子体寿命的乘积与等离子体密度无关,对温度的依赖性较弱。即使这些反应的临界温度低于热核反应堆的临界温度,在惰性等离子体的情况下,临界通量在等离子体密度$ρ_t = 10^{15}/{\rm cm^3}$的$10^{22} - 10^{24}/\rm{cm^2/s}$范围内。讨论了控制双流不稳定性增长的几种方法。我们还考虑了几个实际实施的方案,这些方案需要进一步研究。最后,我们考虑的情况下,注入的光束在共振能量保持等离子体温度和寿命达到稳态。给出了这种情况下的功率平衡方程和粒子数守恒方程。
New Physics Opportunities at Neutrino Facilities: BSM Physics at Accelerator, Atmospheric, and Reactor Neutrino Experiments
Institute for Basic Science(基础科学研究院);University of South Dakota(南达科他大学);Texas A&M University(德克萨斯农工大学);Chungnam National University(忠南国立大学);Jeonbuk National University(全北国立大学);Korea Institute for Advanced Study(韩国高等研究院);Sungkyunkwan University(成均馆大学);Chung-Ang University(中央大学);Tohoku University(东北大学)
The physics reach of a low threshold (100 eV) scintillating argon bubble chamber sensitive to Coherent Elastic neutrino-Nucleus Scattering (CE$ν$NS) from reactor neutrinos is studied. The sensitivity to the weak mixing angle, neutrino magnetic moment, and a light $Z'$ gauge boson mediator are analyzed. A Monte Carlo simulation of the backgrounds is performed to assess their contribution to the signal. The analysis shows that world-leading sensitivities are achieved with a one-year exposure for a 10 kg chamber at 3 m from a 1 MW$_{th}$ research reactor or a 100 kg chamber at 30 m from a 2000 MW…
We study constraints on the Standard Model Effective Field Theory (SMEFT) from neutrino oscillations in short-baseline reactor experiments. We calculate the survival probability of reactors antineutrinos at the leading order in the SMEFT expansion, that is including linear effects of dimension-6 operators. It is shown that, at this order, reactor experiments alone cannot probe charged-current contact interactions between leptons and quarks that are of the (pseudo)vector (V$\pm$A) or pseudo-scalar type. We also note that flavor-diagonal (pseudo)vector coefficients do not have observable effects…
We analyze in detail the physics potential of an experiment like the one recently proposed by the vIOLETA collaboration: a kilogram-scale Skipper CCD detector deployed 12 meters away from a commercial nuclear reactor core. This experiment would be able to detect coherent elastic neutrino nucleus scattering from reactor neutrinos, capitalizing on the exceptionally low ionization energy threshold of Skipper CCDs. To estimate the physics reach, we elect the measurement of the weak mixing angle as a case study. We choose a realistic benchmark experimental setup and perform variations on this bench…
European facilities for accelerator neutrino physics: perspectives for the decade to come
很快,新一代的反应堆和加速器中微子振荡实验--双中微子、大亚湾、里诺和T2 K--将寻找由混合参数θ_13产生的振荡信号。这个角度的知识是一个基本的里程碑,以优化进一步的实验,旨在检测CP破坏的中微子部门。轻子CP破坏是一个在粒子物理学和宇宙学中具有深远意义的关键现象,但它显然是上述实验无法达到的。90年代末以来,世界范围内的一项活动正在进行中,即设计能够探测中微子振荡中CP破坏的装置,并对Cabibbo-Kobayashi-Maskawa矩阵的轻子对应物进行高精度测量。本文将总结这些研究的现状,重点是最适合利用现有欧洲设施(首先是CERN和INFN Gran Sasso实验室)或欧洲拥有世界领先地位的技术的选择。类似的考虑将在更奇异的场景中发展-超出三个活跃中微子之间的味道振荡的标准框架-这可能在MiniBooNE实验或CNGS后出现异常结果时似乎是合理的。
The deployment of a low-noise 3 kg p-type point contact germanium detector at the Dresden-II power reactor, 8 meters from its 2.96 GW$_{th}$ core, is described. This location provides an unprecedented (anti)neutrino flux of 8.1$\times 10^{13} ~\bar{ν_{e}}/$cm$^{2}$s. When combined with the 0.2 keV$_{ee}$ detector threshold achieved, a first measurement of CE$ν$NS from a reactor source appears to be within reach. We report on the characterization and abatement of backgrounds during initial runs, deriving improved limits on extensions of the Standard Model involving a light vector mediator, from…
Evaluation of the neutron background in cryogenic Germanium target for WIMP direct detection when using a reactor neutrino detector as a neutron veto system
For a long time there were 3 main experimental indications in favor of the existence of sterile neutrinos: $\bar{ν_e}$ appearance in the $\bar{ν_μ}$ beam in the LSND experiment, $\bar{ν_e}$ flux deficit in comparison with theoretical expectations in reactor experiments, and $ν_e$ deficit in calibration runs with radioactive sources in the Ga solar neutrino experiments SAGE and GALEX. All three problems can be explained by the existence of sterile neutrinos with the mass square difference in the ballpark of $1~\mathrm{eV^2}$. Recently the MiniBooNE collaboration observed electron (anti)neutrino…
We present new results of measurements of reactor antineutrino flux and spectrum dependence on the distance in the range 6-12 meters from the center of the reactor core at SM-3 reactor (Dimitrovgrad, Russia). Additional measurements were carried out and set of data to perform statistical analysis was almost doubled since the previous report. Using all collected data we performed the model independent analysis on the oscillation parameters $Δm^2_{14}$ and $\sin^2(2θ_{14})$. The method of coherent summation of results of measurements allows us to directly observe the effect of oscillations. We o…
Baksan Experiment on Sterile Neutrino (BEST) is presently at the stage of production of the artificial neutrino source Cr-51, the gallium exposure will start in July and proceed for three months. While aiming specifically at investigating the Gallium neutrino anomaly (SAGE and GALLEX experiments), BEST can do more and it is tempting to estimate its ability in testing sterile neutrino explanation of antineutrino (reactor) anomalies. We observe a moderate sensitivity to the region in model parameter space (sterile neutrino mass and mixing with active electron neutrino) outlined by the old reacto…
Opaque detectors are a recently proposed novel detector concept where an opaque scintillator aligned with wavelength-shifting fibers is used to enable the discrimination of electron neutrinos and antineutrinos with a rather low energy threshold. In this work, we investigate the potential effects of the enhanced detection capabilities of the opaque detectors in accelerator neutrino experiments. Focusing on the energy threshold, energy resolution, detection efficiency and background suppression in the analysis of electron-like events, we determine whether using opaque detectors could lead to imp…