S. Suvorov

The new experiment WAGASCI for water to hydrocarbon neutrino cross section measurement using the J-PARC beam

The T2K (Tokai-to-Kamioka) is a long baseline neutrino experiment designed to study various parameters that rule neutrino oscillations, with an intense beam of muon neutrinos. A near detector complex (ND280) is used to constrain non-oscillated flux and hence to predict the expected number of events in the far detector (Super-Kamiokande). The difference in the target material between the far (water) and near (scintillator, hydrocarbon) detectors leads to the main non-canceling systematic uncertainty for the oscillation analysis. In order to reduce this uncertainty a new water grid and scintillator detector, WAGASCI, has been proposed. The detector will be operated at the J-PARC neutrino beam line with the main physics goal to measure the charged current neutrino cross section ratio between water and hydrocarbon with a few percent accuracy. Further physics program may include high-precision measurements of different charged current neutrino interaction channels. The concept of the new detector will be covered together with the actual construction plan.

Baby MIND: A magnetised spectrometer for the WAGASCI experiment

The WAGASCI experiment being built at the J-PARC neutrino beam line will measure the ratio of cross sections from neutrinos interacting with a water and scintillator targets, in order to constrain neutrino cross sections, essential for the T2K neutrino oscillation measurements. A prototype Magnetised Iron Neutrino Detector (MIND), called Baby MIND, has been constructed at CERN and will act as a magnetic spectrometer behind the main WAGASCI target. Baby MIND will be installed inside the WAGASCI cavern at J-PARC in the beginning of 2018. Baby MIND will be able to measure the charge and momentum of the outgoing muon from neutrino charged current interactions, to enable full neutrino event reconstruction in WAGASCI. nDuring the summer of 2017, Baby MIND was operated and characterised at the T9 test beam at CERN. Results from this test beam will be presented, including charge identification performance and momentum resolution for charged tracks. These results will be compared to the Monte Carlo simulations. Finally, simulations of charge-current quasi-elastic (CCQE) neutrino interactions in an active scintillator neutrino target, followed by the Baby MIND spectrometer, will be shown to demonstrate the capability of this detector set-up to perform cross-section measurements under different assumptions.

The Baby MIND spectrometer for the J-PARC T59(WAGASCI) experiment

The Baby MIND spectrometer is designed to measure the momentum and charge of muons from neutrino interactions in water and hydrocarbon targets at the J-PARC T59 (WAGASCI) experiment. The WAGASCI experiment will measure the ratio of neutrino charged current interaction cross-sections on water and hydrocarbon aiming at reducing systematic errors in neutrino oscillation analyses at T2K. Construction of the Baby MIND detector within the CERN Neutrino Platform framework was completed in June 2017, where it underwent full commissioning and characterization on a charged particle beam line at the Proton Synchrotron experimental hall.

Search for heavy neutrinos in the ND280 near detector of the T2K experiment

The presence of Heavy Neutral Leptons (HNL, M ≈ O(1 GeV)), or heavy sterile neutrinos is proposed in various theories in order to solve current problems of the Standard Model (SM), e.g. the origin of (tiny) neutrino masses, dark matter, baryon asymmetry etc. The T2K provides intense neutrino beam from both pion and kaon parents and hence allows to carry out experimental search for the HNL of 0.44 GeV) and the cross-check of the previous results for lower masses.

New experiment WAGASCI to measure cross sections of neutrino interactions in water and hydrocarbon using J-PARC beam

The main objective of the long base T2K,Tokai-to-Kamioka, Japan, experiment is the investigation of neutrino oscillations with a high-intensity beam of muon neutrinos and antineutrinos. Neutrino interaction measurements in the near detector complex (ND280) of the Т2К experiment are used for adjustment of the parameters defining event simulation in the far detector (Super-Kamiokande), which is the key idea of the experiment; this allows one to considerably increase the oscillation analysis accuracy. The difference in the target material of the far (water) and near (scintillator, hydrocarbon) detectors results in a substantial systematic error in oscillation analysis. Systematic error can be reduced by direct measurements, a new water grid and scintillator detector WAGASCI was proposed for this purpose. The detector will operate at the J-PARC neutrino beam and measure the ratio of charged-current neutrino cross sections between water and hydrocarbon with a few percent precision. Further physical programs may include precise measurements of various charged channels of neutrino interaction. This paper presents the detector concept and the current plan for its installation.

Baby MIND: A magnetized segmented neutrino detector for the WAGASCI experiment

T2K (Tokai-to-Kamioka) is a long-baseline neutrino experiment in Japan designed to study various parameters of neutrino oscillations. A near detector complex (ND280) is located 280 m downstream of the production target and measures neutrino beam parameters before any oscillations occur. ND280s measurements are used to predict the number and spectra of neutrinos in the Super-Kamiokande detector at the distance of 295 km. The difference in the target material between the far (water) and near (scintillator, hydrocarbon) detectors leads to the main non-cancelling systematic uncertainty for the oscillation analysis. In order to reduce this uncertainty a new WAter-Grid-And-SCintillator detector (WAGASCI) has been developed. A magnetized iron neutrino detector (Baby MIND) will be used to measure momentum and charge identification of the outgoing muons from charged current interactions. The Baby MIND modules are composed of magnetized iron plates and long plastic scintillator bars read out at the both ends with wavelength shifting fibers and silicon photomultipliers. The front-end electronics board has been developed to perform the readout and digitization of the signals from the scintillator bars. Detector elements were tested with cosmic rays and in the PS beam at CERN. The obtained results are presented in this paper.