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The JSNS$^2$ experiment aims to search for the existence of neutrino oscillations with $Delta {rm m}^2$ near 1 eV$^2$ at the J-PARC Materials and Life Science Experimental Facility (MLF). A 3~GeV 1~MW proton beam incident on a mercury target produces an intense neutrino source from muon decay at rest ($mu^{+} rightarrow e^{+} + bar{ u}_{mu} + u_{e}$). The oscillation to be searched for is $bar{ u}_{mu}$ to $bar{ u}_{e}$, detected via the inverse beta decay~(IBD) reaction ($bar{ u}_{e} + p rightarrow e^{+} + n$), which is then distinctively tagged by gammas from neutron capture of Gadolinium. The first of two detectors with 17 tons fiducial volume is currently under construction at a distance of 24 m from the mercury target. JSNS$^2$ is expected to provide the ultimate test of the LSND anomaly by replicating nearly identical conditions. The status of the experiment, which is expected to start taking data in Spring 2019, is discussed and its physics potential reviewed.
SNO+ is a large liquid scintillator-based experiment located 2km underground at SNOLAB, Sudbury, Canada. It reuses the Sudbury Neutrino Observatory detector, consisting of a 12m diameter acrylic vessel which will be filled with about 780 tonnes of ultra-pure liquid scintillator. Designed as a multipurpose neutrino experiment, the primary goal of SNO+ is a search for the neutrinoless double-beta decay (0$ ubetabeta$) of 130Te. In Phase I, the detector will be loaded with 0.3% natural tellurium, corresponding to nearly 800 kg of 130Te, with an expected effective Majorana neutrino mass sensitivity in the region of 55-133 meV, just above the inverted mass hierarchy. Recently, the possibility of deploying up to ten times more natural tellurium has been investigated, which would enable SNO+ to achieve sensitivity deep into the parameter space for the inverted neutrino mass hierarchy in the future. Additionally, SNO+ aims to measure reactor antineutrino oscillations, low-energy solar neutrinos, and geoneutrinos, to be sensitive to supernova neutrinos, and to search for exotic physics. A first phase with the detector filled with water will begin soon, with the scintillator phase expected to start after a few months of water data taking. The 0$ ubetabeta$ Phase I is foreseen for 2017.
The determination of the neutrino mass hierarchy, whether the $ u _3$ neutrino mass eigenstate is heavier or lighter than the $ u _1$ and $ u _2$ mass eigenstates, is one of the remaining undetermined fundamental aspects of the Standard Model in the lepton sector. Furthermore the mass hierarchy determination will have an impact in the quest of the neutrino nature (Dirac or Majorana mass terms) towards the formulation of a theory of flavour. The Jiangmen Underground Neutrino Observatory (JUNO) is a reactor neutrino experiment under construction at Kaiping, Jiangmen in Southern China composed by a large liquid scintillator detector (sphere of 35.4 m of diameter) surronding by 18000 large PMTs and 25000 small PMTs, a water cherenkov detector and a top tracker detector. The large active mass (20 kton) and the unprecedented energy resolution (3% at 1 MeV) will allow to determine the neutrino mass hierarchy with good sensitivity and to precisely measure the neutrino mixing parameters, $theta _{12}$, $Delta m^2_{21} $, and $Delta m^2_{ee}$ below the 1% level. Moreover, a large liquid scintillator detector will allow to explore physics beyond mass hierarchy determination, in particular on many oyher topics such as in astroparticle physics, like supernova burst and diffuse supernova neutrinos, solar neutrinos, atmospheric neutrinos, geo-neutrinos, nucleon decay, indirect dark matter searches and a number of additional exotic searches. In this work the status and the perspectives of the JUNO experiment will be described, focusing also on the main physics aims and the other possible physics cases.
The KATRIN experiment, presently under construction in Karlsruhe, Germany, will improve on previous laboratory limits on the neutrino mass by a factor of ten. KATRIN will use a high-activity, gaseous T2 source and a very high-resolution spectrometer to measure the shape of the high-energy tail of the tritium-decay beta spectrum. The shape measurement will also be sensitive to new physics, including sterile neutrinos and Lorentz violation. This report summarizes recent progress in the experiment.
The PIENU experiment at TRIUMF aims to measure the pion decay branching ratio $R={Gamma}({pi}^+{rightarrow}e^+{ u}_e({gamma}))/{Gamma}({pi}^+{rightarrow}{mu}^+{ u}_{mu}({gamma}))$ with precision $<0.1$% to provide a sensitive test of electron-muon universality in weak interactions. The current status of the PIENU experiment is presented.
KIMS-NaI is a direct detection experiment searching for Weakly Interacting Massive Particles (WIMP) via their scattering off of nuclei in a NaI(Tl) crystal. The KIMS-NaI collaboration has carried out tests of six crystals in the Yangyang underground laboratory in order to develope low-background NaI(Tl) crystals. Studies of internal backgrounds crystals have been performed with the goal of reducing backgrounds levels to 1 dru at 2 keV. Pulse shape discrimination (PSD) capabilities were also investigated for distinguishing between WIMP nuclear recoil signals and electron recoil backgrounds. The PSD analysis was applied to underground data with one low background NaI(Tl) detector and the evaluation of WIMP mass limit is ongoing.