Nucleon Decay and Neutrino Experiments (T2K ND80 Detector Maintenance and Operation Common Funds)

NucleondecayandNeutrinoExperiments (T2KDetectorMaintenanceandOperationsCommonFunds) Period:November1,2024-october31,2028 PI:ChangKeeJung Dept.ofPhysicsandAstronomy TheStateUniversityofNewYorkatStonyBrook 100NicollsRoad StonyBrook,NewYork11794-3800 T2K is the first long baseline neutrino oscillation experiment proposed and approved for searching for an electron neutrino appearance signature from the oscillations of muon neutrinos using accelerator generated neutrino beams. The observation of electron neutrino appearance in 2013 byT2K paved the way to determine the neutrino mass ordering 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. In fact, T2K has recently released the results that show aninitial hint of CP violation (closed 3 sigma ranges ofCP phasefor both Normal and Inverted mass orderingcentered around -90o). T2K uses Super-Kamiokande as the far detector to measure neutrino rates and spectrum at adistance of 295 km from the accelerator. The experiment also uses a neutrino beamline and  a near detector complex (ND280) in J-PARC at 280 m from the proton target. The ND280 complex houses bothon-axis and off-axis detectors. The on-axis detector measures the neutrino beam direction andprofile. A fine-grained off-axis detector serves to measure the flux, energy spectrum and intrinsic electronneutrino component in the direction of the far detector, along with measuring rates for exclusiveneutrino reactions. This characterizes signals and backgrounds in the Super-Kamiokande detector. The off-axis detector has been upgraded recently (2020-2024) in order to improve the overall performance of ND280, and reduce the systematic uncertainties for the neutrino oscillation analyses.  The upgraded off-axis detector consists of the upstream pi-zero detector acting as a veto, SuperFGD (a 3D projection scintillator tracker), two High Angel TPCs, six Time-of-flight detectors, and a tracker system  (TPC-Fine Grained Detector sandwich).  These detectors are placed inside of an electromagnetic calorimeter (ECAL) which is further surrounded by the recycled UA1 magnet.  The UA1 magnet provides up to a 0.2 T field to momentum analyze the charged particles in the innerdetector, and is instrumented with scintillator to perform as a muon range detector (the SMRD). The T2K collaboration is composed of ~500 members from 78 institutions from 12 countries: Canada, France, Germany, Italy, Japan, Poland, Russia, Spain, Switzerland, U.K., U.S. and Vietnam.  The current T2K US collaboration is composed of 13 institutions:Boston U,U. of California, Irvine,Duke U.,LBNL,Louisiana State U.,Michigan State U.,SLAC,South Dakota School of Mines and Technology,Stony Brook U.,U. of Colorado,U. of Houston,U. of Pittsburgh andU. of Rochester.The proposed budget in this proposal will be used for the T2K detector maintenance and operations for the next four years in the form of``common funds''.  Specifically, it will be used as U.S. contributions to the T2K ND280 detector maintenance and operations, and to support the maintenance and operations of the U.S. contributed subsystems of the ND280 detector.The funds will be managed by the Stony Brook University with Prof. Jung as the PI as it has been since 2009.  Jung served as International Co-Spokesperson of the T2K collaboration during 2011-2015.  He also has been serving asSpokesperson of the T2K US Collaboration since 2004. The off-axis detector in turn consists of the PØD detector and a tracker (TPC-Fine GrainedDetector sandwich). Both of these detectors are placed inside of an electromagnetic calorimeter(ECAL) which is further surrounded by the recycled UA1 magnet. The UA1 magnet provides up toa 0.2 T field to momentum analyze the charged particles in the inner detector, and is instrumentedwith scintillator to perform as a muon range detector (the SMRD). During 2020-2022 the ND280detector will be upgraded. Most of the PØD detector will be removed and in place, a 3D-projectionscintillator tracker, called the SuperFGD, and two high-angle TPCs will be installed in order to improve the overall performance of ND280, and reduce the systematic uncertainties for the neutrinooscillation analyses. The T2K collaboration is composed of 500 members from 65 institutions from 12 countries:Canada, France, Germany, Italy, Japan, Poland, Russia, Spain, Switzerland, U.K., U.S. and Vietnam. The current T2K US collaboration is composed of 12 institutions: Boston U, U. of California,Irvine, Colorado State U., Duke U., Louisiana State U., Michigan State U., SLAC, Stony BrookU., U. of Colorado, U. of Houston, U. of Pittsburgh and U. of Rochester. The proposed budget in this proposal will be used for the T2K detector maintenance andoperations, and T2K upgrade related work for the next four years in the form of “common funds”.Specifically, it will be used as U.S. contributions to the T2K ND280 detector maintenance andoperations, and to support the maintenance and operations of the U.S. contributed subsystems ofthe ND280 detector. It will be also used to support the SuperFGD electronics design work. The funds will be managed by the Stony Brook University with Prof. Jung as the PI as it hasbeen since 2009.  Jung served as International Co-Spokesperson of the T2K collaboration during2011-2015.  He also has been serving as Spokesperson of the T2K US Collaboration since 2004.