We review what has been learned about the neutrinos, and then discuss the open questions, explaining why they are interesting and how they may be answered through future experiments.
Super-Kamiokande (Super-K) is an already successful experiment in neutrino research, involved in the discovery of the neutrino oscillations, and performing analysis on a large spectrum of the neutrino physics: from atmospheric neutrinos to solar neutrinos, including neutrino produced by the J-PARC beam in the T2K experiment. The Super-K collaboration is now aiming at the detection of Supernova...
Deeper understanding of neutrino neutral current elastic interaction is desired for improving sensitivity in search for supernova relic neutrinos at Super-Kamiokande. Measuring the interaction with the T2K beam is a effective way, however, currently large systematic errors remain due to a poor model to describe neutron-oxygen reactions. To improve the current model, external experiments...
The Reactor Experiment for Neutrino Oscillation (RENO) has been taking data from August, 2011 using the two identical near and far detectors at Hanbit Nuclear Power Plant in Korea. The neutrino mixing angle θ13 and the squared mass difference Δm2ee have been successfully measured by observing the energy dependent disappearance of reactor antineutrinos tagged by neutron capture by gadolinium....
New physics signals with displaced vertices have attracted the recent attention of the collider community (theoretical and experimental). In this talk, we will describe how a model of non-sterile right-handed neutrinos with masses being proportional to the electroweak scale (~246 GeV) naturally gives rise to long-lived particles with displaced vertices as characteristic signals. An interesting...
Recent re-evaluations of antineutrino spectrum emitted by nuclear reactor have led to the observation of a ~7% deficit in neutrino flux at short distance from reactors with respect to predictions. This deficit, known as the Reactor Antineutrino Anomaly (RAA), could be the signature of an oscillation of antineutrino towards a light sterile neutrino with a mass scale of 1eV. However, it is not...
DANSS is a one cubic meter highly segmented solid scintillator detector.
It consists of 2500 scintillator strips (100x4x1 cm3), covered with
gadolinium loaded reflective coating and read out with SiPMs via wave length
shifting fibers. Groups of 50 strips are also read out by conventional
PMTs. DANSS is placed under a 3 GW industrial reactor at the Kalinin NPP (Russia) on a movable platform....
Borexino as the leading liquid-scintillator-based low background experiment has given opportunities for a vast number of physics programs. After extensive water extraction campaign during 2011, the purity of liquid scintillator is even better. With 1291.51 days of Borexino Phase-II data collected since then, we performed for the first time a global fit and simultaneous measurement of...
Ultrahigh energy (UHE) neutrinos may serve as important messengers that give us useful information about the origin of the Universe. Knowledge of UHE neutrino interaction cross sections is a necessary ingredient in any UHE neutrino measurement. A study of UHE neutrino-nucleon cross sections would also allow us to explore strong interactions at incredibly high energies. In this talk, I review...
WAGASCI is an experiment to measure neutrino interactions at the J-PARC neutrino beam line. The central WAGASCI module has a 3-dimensional grid target structure made of scintillator and water. The module is surrounded on either side by two side muon range detectors (MRD) and downstream by a magnetized MRD called Baby MIND. Baby MIND consists of iron-core magnet planes, with a magnetic field...
The violation of Lorentz invariance is predicted by most of the theories beyond the Standard Model as string theories or quantum loop gravities. It arises as a consequence of merging the Standard Model with gravity, whose effects appear at the Planck mass scale. Therefore, the observation of the violation of Lorentz invariance (and CPT invariance) is searched as a very strong hint of physics...
Leptogenesis is an elegant scenario where the baryon asymmetry of the Universe is produced from a lepton asymmetry generated in the decays of a heavy right-handed neutrino. In this talk, I will briefly review on the novel mechanism and discuss whether we can test the scenario by current/future experiments. In the latter half of the talk, I would like to give you a concrete example of the...
The PandaX (Particle AND Astrophysical Xenon experiment) project, located at China JinPing underground Laboratory (CJPL), uses xenon Time Projection Chambers (TPC) to search for the dark matter particles as well as the Neutrinoless Double Beta Decay (NLDBD) of Xe-136 isotope. The second phase of the experiment, PandaX-II, is a 500 kg scale dual phase liquid xenon TPC and has been one of the...
The Jiangmen Underground Neutrino Observatory (JUNO) is a multiple-purpose neutrino experiment with a 20 kilotons liquid scintillator (LS) detector. It is built at a depth of 700 meters from two nuclear power plants with a ~53 kilometers baseline. The main goal of JUNO is achieving an unprecedented 3% energy resolution at 1 MeV to determine the neutrino mass hierarchy in 6 years with a 3-4...
KamLAND-Zen searches for neutrinoless double beta
decay of Xe-136 using Xe-loaded liquid scintillator(XeLS). The
experiment holds XeLS in the nylon-film vessel(inner balloon, IB) at the center of KamLAND, low-background 1-kton liquid
scintillator detector. First stage of the experiment, KamLAND-Zen 400 (Zen 400), has run with 380-kg of Xe until 2015 and
its result set the most stringent...
Although recent oscillation experiments have advanced neutrino physics impressively by discovering finite neutrino masses along with their mixing, there still exist important uncovered neutrino properties such as absolute neutrino massesand the nature of neutrino masses, Majorana/Dirac distinction.The SPAN (SPectroscopy with Atomic Neutrino) group at Okayama University aims to uncover these...
The neutrinoless double beta decay, if it happens, is a very rare phenomenon. A detector with mass scalability up to ton scale and strong background rejection power is necessary to search for it.
We are aiming to achieve these requirements with a high-pressure xenon gas time projection chamber. Our detector, AXEL, has high energy resolution and tracking pattern detection, which are important...
The knowledge about tau neutrino features is still rather poor comparing with muon or electron neutrino. One of the basic features, the tau neutrino cross-section, was only measured by DONUT in 2008 with large systematical error of 50% and also large statistical error of 33%.
In the future experiments, a large number of tau neutrino events will be collected for precise measurement on tau...
We present a status of COBAND project for an experimental search for COsmic BAckground Neutrino Decay. The cosmic background neutrino (C$\nu$B) is predicted in the standard cosmology, while the heaviest neutrino is expected to be able to decay to lighter neutrinos with photons in the FIR region. Neither the C$\nu$B nor the neutrino decay is, however, experimentally established yet. We, thus,...
