Public Abstract

DE-SC0020667: US Participation in the Construction of the T2K SuperFGD Detector as Part of the T2K ND280 Upgrade

Award Status: Inactive

Institution: Research Foundation for the State University of New York d/b/a RFSUNY - Stony Brook University, Stony Brook, NY
UEI: M746VC6XMNH9
DUNS: 804878247

Most Recent Award Date: 12/05/2023
Number of Support Periods: 3
PM: Crawford, Glen

Current Budget Period: 11/01/2021 - 04/30/2024
Current Project Period: 11/01/2019 - 04/30/2024
PI: Jung, Chang Kee

Supplement Budget Period: N/A

Public Abstract

There have been astonishing advances in neutrino physics during the last two decades. Before 1998, there was no neutrino oscillation, meaning no neutrino mass and mixing. Today, neutrino oscillation is firmly established. Oscillations connect the three neutrino generations with three mixing angles. There are three neutrino masses, but oscillation measurements can only determine the differences between the squares of the masses so there are only two unique mass parameters measurable. We have in fact measured all three mixing and two mass parameters. Furthermore, these findings pave the way toward determine the mass ordering/hierarchy and to explore Charge-Parity (CP) violation in the lepton sector, which may hold a critical key to our understanding of the matter−antimatter asymmetry in the universe, one of the most profound mysteries in science. In fact, T2K, a long baseline neutrino oscillation experiment based in Japan, has recently released results that show an initial hint of CP violation (closed 3σ ranges of δ_CP for both Normal and Inverted mass ordering centered around −90^o) making the prospects of DUNE, a next generation long baseline neutrino oscillation experiment based in U.S., for discovering CP violation in neutrinos very bright. Neutrino oscillation which requires non-zero neutrino mass is considered the only phenomenon beyond the Standard Model observed in laboratory venue today. The T2K experiment uses a 30 GeV proton beam accelerated by the J-PARC accelerator facility. The facility comprises (1) the neutrino beamline, (2) the Near Detector (ND) complex, which is located 280 m downstream of the neutrino production target and (3) the far detector, Super-Kamiokande, which detects neutrinos at a baseline distance of 295 km from the target. T2K data taking started in January 2010 and stable beam operation at 480 kW beam power has been achieved. In all, the total integrated data collected for physics analysis so far is 1.51x10²¹ POT (Protons-On-Target) in neutrino-mode and 1.65x10²¹ POT in antineutrino-mode giving a POT total of 3.16x10²¹which is 41% of the total approved POT for T2K (7.8x10²¹). The most recent results from the T2K oscillation analysis are consistent with θ₂₃ at maximal mixing, δ_CP= -π/2 and normal mass ordering. The CP conserving δ_CP= 0 and are now disfavored at 95% C.L. In order to increase the sensitivity for CPV, T2K proposes an extended run ("T2K-II"). The plan calls for accelerator and beamline upgrades for 1.3 MW beam power and accumulation of data corresponding to >10x10²¹ POT. The aim of T2K-II is to achieve 3 sensitivity for CPV at the currently favored oscillation parameters. In addition, T2K proposes to upgrade the ND280 detector in order to reduce systematic uncertainty for electron neutrino appearance to the 4% level, matching the needs of the T2K physics for the extended run period. This can be obtained with the addition of a novel highly granular scintillator detector, SuperFGD, which is composed of fully active small scintillator cubes, with a 1 cm side, each read out with three WLS fibers. This detector is sandwiched between two High-Angle TPC, read out by resistive Micromegas detectors, with a compact and light field cage. These detectors are surrounded by six large TOF planes to determine the track direction and improve the PID. We request DOE support for US participation in the construction of the SuperFGD detector as part of the T2K ND280 upgrade for the period April 1, 2019 - March 31, 2022 With this proposal, however, we are looking beyond T2K, namely, DUNE. In 2017-2018, recognizing a need for an advanced fully active scintillator tracker in the DUNE ND, we pushed forward a plan to synthesize the T2K SuperFGD effort and DUNE ND design effort by proposing a "3D-projection Scintillator Tracker (3DST)" that has essentially the same detector characteristics as SuperFGD. In this scheme, the T2K SuperFGD becomes a fully working prototype of the DUNE 3DST allowing the US groups involved in both projects to utilize the overall resources efficiently and also transfer the expertise and knowledge gained from SuerFGD to 3DST most effectively. This will also allow the groups to attract and train students and postdocs for DUNE, while continuing intellectual leadership roles within T2K via effective contributions to the upgrade. Recently, a "hybrid" detector with a Liquid Argon TPC + High Pressure gas TPC + 3DST with KLOE magnet has been adopted as the baseline design for DUNE ND.

There have been astonishing advances in neutrino physics during the last two decades. Before 1998, there was no neutrino oscillation, meaning no neutrino mass and mixing. Today, neutrino oscillation is firmly established. Oscillations connect the three neutrino generations with three mixing angles. There are three neutrino masses, but oscillation measurements can only determine the differences between the squares of the masses so there are only two unique mass parameters measurable. We have in fact measured all three mixing and two mass parameters. Furthermore, these findings pave the way toward determine the mass ordering/hierarchy and to explore Charge-Parity (CP) violation in the lepton sector, which may hold a critical key to our understanding of the matter−antimatter asymmetry in the universe, one of the most profound mysteries in science. In fact, T2K, a long baseline neutrino oscillation experiment based in Japan, has recently released results that show an initial hint of CP violation (closed 3σ ranges of δ_CP for both Normal and Inverted mass ordering centered around −90^o) making the prospects of DUNE, a next generation long baseline neutrino oscillation experiment based in U.S., for discovering CP violation in neutrinos very bright. Neutrino oscillation which requires non-zero neutrino mass is considered the only phenomenon beyond the Standard Model observed in laboratory venue today.

The T2K experiment uses a 30 GeV proton beam accelerated by the J-PARC accelerator facility. The facility comprises (1) the neutrino beamline, (2) the Near Detector (ND) complex, which is located 280 m downstream of the neutrino production target and (3) the far detector, Super-Kamiokande, which detects neutrinos at a baseline distance of 295 km from the target. T2K data taking started in January 2010 and stable beam operation at 480 kW beam power has been achieved. In all, the total integrated data collected for physics analysis so far is 1.51x10²¹ POT (Protons-On-Target) in neutrino-mode and 1.65x10²¹ POT in antineutrino-mode giving a POT total of 3.16x10²¹which is 41% of the total approved POT for T2K (7.8x10²¹). The most recent results from the T2K oscillation analysis are consistent with θ₂₃ at maximal mixing, δ_CP= -π/2 and normal mass ordering. The CP conserving δ_CP= 0 and are now disfavored at 95% C.L. In order to increase the sensitivity for CPV, T2K proposes an extended run ("T2K-II"). The plan calls for accelerator and beamline upgrades for 1.3 MW beam power and accumulation of data corresponding to >10x10²¹ POT. The aim of T2K-II is to achieve 3 sensitivity for CPV at the currently favored oscillation parameters. In addition, T2K proposes to upgrade the ND280 detector in order to reduce systematic uncertainty for electron neutrino appearance to the 4% level, matching the needs of the T2K physics for the extended run period. This can be obtained with the addition of a novel highly granular scintillator detector, SuperFGD, which is composed of fully active small scintillator cubes, with a 1 cm side, each read out with three WLS fibers. This detector is sandwiched between two High-Angle TPC, read out by resistive Micromegas detectors, with a compact and light field cage. These detectors are surrounded by six large TOF planes to determine the track direction and improve the PID.

We request DOE support for US participation in the construction of the SuperFGD detector as part of the T2K ND280 upgrade for the period April 1, 2019 - March 31, 2022

With this proposal, however, we are looking beyond T2K, namely, DUNE. In 2017-2018, recognizing a need for an advanced fully active scintillator tracker in the DUNE ND, we pushed forward a plan to synthesize the T2K SuperFGD effort and DUNE ND design effort by proposing a "3D-projection Scintillator Tracker (3DST)" that has essentially the same detector characteristics as SuperFGD. In this scheme, the T2K SuperFGD becomes a fully working prototype of the DUNE 3DST allowing the US groups involved in both projects to utilize the overall resources efficiently and also transfer the expertise and knowledge gained from SuerFGD to 3DST most effectively. This will also allow the groups to attract and train students and postdocs for DUNE, while continuing intellectual leadership roles within T2K via effective contributions to the upgrade. Recently, a "hybrid" detector with a Liquid Argon TPC + High Pressure gas TPC + 3DST with KLOE magnet has been adopted as the baseline design for DUNE ND.