Neutrino-4 experiment on search for sterile neutrino with multi-section model of detector

Abstract

In order to carry out research in the field of possible existence of a sterile neutrino the laboratory based on SМ-3 reactor (Dimitrovgrad, Russia) was created to search for oscillations of reactor antineutrino. The prototype of a multi-section neutrino detector with liquid scintillator volume of 350 l was installed in the middle of 2015. It is a moveable inside the passive shielding detector, which can be set at distance range from 6 to 11 meters from the reactor core. Measurements of antineutrino flux at such small distances from the reactor core are carried out with moveable detector for the first time. The measurements carried out with detector prototype demonstrated a possibility of measuring a reactor antineutrino flux in difficult conditions of cosmic background at Earth surface. * serebrov@pnpi.spb.ru

First Search for Short-Baseline Neutrino Oscillations at HFIR with PROSPECT

“…Of these, the sterile neutrino hypothesis has received particular attention due to its broad potential impact and to existing supporting experimental indications from accelerator and radioactive source neutrino experiments [14][15][16][17][18]. A range of experimental [19][20][21][22][23], theoretical [24][25][26][27][28], and global analysis [29][30][31][32] efforts have sought to understand the origin of these discrepancies.…”

“…Widely cited global fits of this oscillation model to historical neutrino data have suggested values of Δm 2 41 and θ 14 of ∼2 eV 2 and ∼0.15, respectively [13]; we refer to this best-fit point and the surrounding 95% confidence level allowed region as the "reactor antineutrino anomaly" oscillation parameter space. New experiments seek to unambiguously test this hypothesis via differential measurements of theν e energy spectrum over a range of short Oð10Þ m baselines [21][22][23]34,35]. Such efforts are complicated by the need to perform precisionν e measurements in the challenging background environment close to a reactor core and near Earth's surface with little overburden [34].…”

“…To perform a differential test of oscillation-induced spectral distortion, an IBD response model is generated for all detector positions using PG4, a GEANT4-based [44] Monte Carlo (MC) simulation package developed by the collaboration. Accurate energy scale, nonlinearity, and energy resolution simulation are established via a simultaneous fit to the energy spectra of 137 Cs, 22 Na, and 60 Co center-deployed calibration sources and the β þ γ-ray spectrum of cosmogenic 12 B distributed uniformly throughout the detector volume. MC data are generated for each calibration data set in PG4 using an energy response model with two LS nonlinearity parameters, one photostatistics resolution parameter, and one absolute energy scale parameter.…”

A new scheme for short baseline electron antineutrino disappearance study

“…This fourth neutrino, so-called sterile neutrinos (ν s ), is claimed to play important roles of explaining some anomalies reported in LSND [2], MiniBoone [3], reactor experiments [4], and gallium experiments [5]. A few experiments with compact neutrino detectors and reactor facilities [6,7,8,9,10,11] or antineutrino sources from radioactive isotopes [12,13,14] or an accelerator-based IsoDAR (isotope decay-at-rest) [15,16,17] are proposed to search the existence of ν s . By using compact neutrino detectors such as DANSS [6], NEUTRINO4 [7], NUCIFER [8], PANDA [9], PROSPECT [10], and STEREO [11], experiments have been planned to measure reactor neutrinos at a distance of several meters.…”

“…A few experiments with compact neutrino detectors and reactor facilities [6,7,8,9,10,11] or antineutrino sources from radioactive isotopes [12,13,14] or an accelerator-based IsoDAR (isotope decay-at-rest) [15,16,17] are proposed to search the existence of ν s . By using compact neutrino detectors such as DANSS [6], NEUTRINO4 [7], NUCIFER [8], PANDA [9], PROSPECT [10], and STEREO [11], experiments have been planned to measure reactor neutrinos at a distance of several meters. KamLAND (CeLAND) [13] and Borexino (SOX) [14] plan to perform experiments by using antineutrino generators of unstable isotopes 144 Ce-144 Pr of a radioactivity of 100 kCi, where neutrino energies are lower than 3 MeV.…”