IntroductiontoJUNO

TheJiangmenUndergroundNeutrinoObservatory(JUNO)isamultipurposeneutrinoexperimentdesignedtodetermineneutrinomasshierarchyandpreciselymeasureoscillationparametersbydetectingreactorneutrinosfromtheYangjiangandTaishanNuclearPowerPlants,observesupernovaneutrinos,studytheatmospheric,solarneutrinosandgeo-neutrinos,andperformexoticsearches,witha20-thousand-tonliquidscintillatordetectorofunprecedented3%energyresolution(at1MeV)at700-meterdeepunderground.

Scientificgoals

NeutrinosareelementaryparticlesintheStandardModel.Therearethreeflavorsofneutrinos,knownasνe,νμandντ.Theneutrinoflavorstatesaresuperpositionsofthreemasseigenstates(ν1,ν2andν3),whichundergoquantuminterferenceduringthetraveling,causingneutrinoflavorchanges.Thisphenomenonisknownasneutrinooscillationorneutrinomixing.Theamplitudesofoscillationareconnectedtothemixinganglesθ12,θ23andθ13.Theoscillationfrequenciesaredeterminedbythedifferenceofsquaredneutrinomasses,Δm2ij=m2i-m2j.

θ12andΔm221weremeasuredbysolarneutrinoexperimentsandareactorneutrinoexperimentKamLAND.θ23and|Δm232|weremeasuredbyatmosphericandacceleratorneutrinoexperiments.Thelastunknownmixingangleθ13wasdeterminedtobeunexpectedlylargebytheDayaBayReactorNeutrinoExperiment,aswellasotherreactorneutrinoexperimentsDoubleChoozandRENO,andacceleratorneutrinoexperimentsT2KandMINOS.Thesemeasurementsopenaneweraofneutrinoexperiments.ThenextgenerationneutrinooscillationexperimentswillfocusondeterminingthesignofΔm232(masshierarchy),preciselymeasuringalloscillationparametersandsearchingforCPviolationintheneutrinooscillation.

ThemajorgoalofJUNOisdeterminingneutrinomasshierarchybypreciselymeasuringtheenergyspectrumofreactorelectronantineutrinosatadistanceof~53kmfromthereactors.Arel