Status of JSNS2 - J-PARC Sterile Neutrino Search at J-PARC Spallation Neutron Source

Carsten Rott

doi:10.1088/1742-6596/1468/1/012176

Abstract

The JSNS2 experiment will search for neutrino oscillations with Δm2 ≃ 1 eV2 from to , detected via the inverse beta decay (IBD) reaction and tagged via gammas from neutron capture on Gadolinium. A 3 GeV 1 MW proton beam incident on a mercury target at the Materials and Life Science Experimental Facility at J-PARC produces an intense neutrino flux from muon decay at rest . The first of two 50 tons liquid scintillator detectors is nearly completed and will be located at a distance of 24 m from the neutrino source. JSNS2 can directly test the LSND anomaly and is expected to start taking data in early 2020.

Highlights

For almost two decades the neutrino community has been intrigued by anomalies that could hint at the existence of a light sterile neutrino that participates in neutrino oscillations
One of the longest standing anomalies (3.8 σ) was observed as an excess of νe events in data collected with the Liquid Scintillator Neutrino Detector (LSND) at Los Alamos in 1998 [1]
Major improvements in the experimental setup of JSNS2 with respect to LSND include: (1) The high intensity short pulsed beam at MLF significantly reduces coincidental backgrounds; (2) Gd-doped liquid scintillator (LS) allows to tag inverse beta decay (IBD) events; (3) The detector location of JSNS2 is above the beam dump reducing the possibility of beam related backgrounds that have been suggested as contributing to the observed LSND signal

Summary

Introduction

For almost two decades the neutrino community has been intrigued by anomalies that could hint at the existence of a light sterile neutrino that participates in neutrino oscillations. One of the longest standing anomalies (3.8 σ) was observed as an excess of νe events in data collected with the Liquid Scintillator Neutrino Detector (LSND) at Los Alamos in 1998 [1] (see table 1). The MiniBooNE experiment later observed anomalies in both νe and νe appearance channels (combined 4.8 σ) [2].

Results

Conclusion