OUTLINE ν e Magnetic . . . Neutrino Physics with Gemanium Detector ¯ Limits of . . . ν e e − → ¯ ν e e − . . . ¯ at the Kuo-Sheng reactor neutrino laboratory KS Expt. : . . . KS Expt. : . . . µ ν with Reactor ¯ ν e KS/P1/Ge/ µ ν Data Cosmic Veto, . . . Efficiency & . . . KS/P1/Ge/ µ ν : . . . Sensitivity Period II & III . . . ν e spectrum . . . ¯ Quenching factor Integral Spectrum Calibration data Summary NTHU, Hsinchu 2004 Feb 10 � � � � � � � � �
OUTLINE OUTLINE ν e Magnetic . . . ¯ Limits of . . . ν e e − → ¯ ν e e − . . . ¯ ◮ Neutrino magnetic moment : Overview KS Expt. : . . . KS Expt. : . . . ◮ Period I experiment : Magnetic moment results µ ν with Reactor ¯ ν e KS/P1/Ge/ µ ν Data ◮ Period II, III status and plans Cosmic Veto, . . . Efficiency & . . . ν e N coherent scattering ¯ ◮ KS/P1/Ge/ µ ν : . . . Sensitivity ◮ LEGe prototype measurements with sources Period II & III . . . ν e spectrum . . . ¯ ◮ Summary Quenching factor Integral Spectrum Calibration data Summary � � � � � � � � �
OUTLINE ν e Magnetic moment ¯ ν e Magnetic . . . ¯ Limits of . . . ν e e − → ¯ ν e e − . . . ¯ KS Expt. : . . . KS Expt. : . . . µ ν with Reactor ¯ ν e KS/P1/Ge/ µ ν Data Cosmic Veto, . . . Efficiency & . . . KS/P1/Ge/ µ ν : . . . Sensitivity Period II & III . . . ν e spectrum . . . ¯ Quenching factor Integral Spectrum Calibration data D µ : magnetic moment Summary µ 2 eff ≡ | D µ − D E | 2 D E : electric dipole moment µ ν ≈ 10 − 10 µ B → consistent with solar data(before KamLand results) → could be reached by present lab. exp. � � � � � � � � �
OUTLINE Limits of neutrino magnetic moment ν e Magnetic . . . ¯ Limits of . . . ♯ PDG quoted : ν e e − → ¯ ν e e − . . . ¯ KS Expt. : . . . Fit on SuperK data, µ ν < 1 . 5 × 10 − 10 µ B ( ν e e − scattering) • KS Expt. : . . . ν e e − scattering : ♯ Reactor ¯ µ ν with Reactor ¯ ν e KS/P1/Ge/ µ ν Data Savannah River(plastic scintillator), µ ν ≈ 2 − 4 × 10 − 10 µ B • Cosmic Veto, . . . Kurtchatoc(fluorocarbon scintillator), µ ν < 2 . 4 × 10 − 10 µ B Efficiency & . . . • KS/P1/Ge/ µ ν : . . . Rovno(Si(Li)), µ ν < 1 . 9 × 10 − 10 µ B • Sensitivity Period II & III . . . MUNU(CF 4 ), threshold ∼ 1 MeV. • ν e spectrum . . . ¯ ♯ Astrophysics bound : Quenching factor Integral Spectrum ν L → ν R in SN1987A, µ ν < (0 . 01 − 0 . 04) × 10 − 10 µ B • Calibration data Constraint on nucleosynthesis, µ ν < 0 . 62 × 10 − 10 µ B Summary • Red giant luminosity, µ ν < 0 . 03 × 10 − 10 µ B • – depend on neutrino mass/interaction. – depend on stellar model. � � � � � � � � �
ν e e − → ¯ ν e e − Scattering OUTLINE ¯ ν e Magnetic . . . ¯ Limits of . . . ν e e − → ¯ ν e e − . . . ¯ KS Expt. : . . . ν e e − → ¯ ν × e − ¯ KS Expt. : . . . µ ν with Reactor ¯ ν e Mesurement : Recoil energy of e − KS/P1/Ge/ µ ν Data Cosmic Veto, . . . Efficiency & . . . KS/P1/Ge/ µ ν : . . . Sensitivity Period II & III . . . ν e spectrum . . . ¯ Quenching factor Integral Spectrum Calibration data When recoil energy T → 0 Summary ( dσ ( dσ dT ) MM → 1 dT ) SM → constant, T � � � � � � � � �
OUTLINE KS Expt. : Period I Configuration ν e Magnetic . . . ¯ Period I : June 01 - April 02 Limits of . . . ν e e − → ¯ ν e e − . . . ¯ KS Expt. : . . . Two detectors in inner target : KS Expt. : . . . HPGe and CsI(Tl) array. µ ν with Reactor ¯ ν e KS/P1/Ge/ µ ν Data Cosmic Veto, . . . Inner targer flush with nitrogen. Efficiency & . . . KS/P1/Ge/ µ ν : . . . Sensitivity Period II & III . . . ν e spectrum . . . ¯ Quenching factor Integral Spectrum Calibration data Summary � � � � � � � � �
OUTLINE KS Expt. : Period I Detectors ν e Magnetic . . . ¯ ULB-HPGe [1 kg] CsI(Tl) [46 kg] Limits of . . . ν e e − → ¯ ν e e − . . . ¯ KS Expt. : . . . KS Expt. : . . . µ ν with Reactor ¯ ν e KS/P1/Ge/ µ ν Data Cosmic Veto, . . . Efficiency & . . . KS/P1/Ge/ µ ν : . . . Sensitivity Period II & III . . . ν e spectrum . . . ¯ Quenching factor Integral Spectrum Calibration data Summary FADC : 16 ch., Data : 600 Gb 20 MHz, 8 bit � � � � � � � � �
OUTLINE µ ν with Reactor ¯ ν e ν e Magnetic . . . ¯ Limits of . . . ⋆ µ ν : ν e e − → ¯ ν e e − . . . ¯ ◮ parametrize possible ν iL → ν jR + γ vertices KS Expt. : . . . KS Expt. : . . . ◮ ∃ both i = j ”diagonal” & i � = j ”transition” moments µ ν with Reactor ¯ ν e KS/P1/Ge/ µ ν Data ⋆ Experimental Probe : ν e + e − → ¯ Cosmic Veto, . . . ν x + e − ◮ Study ¯ Efficiency & . . . ◮ Focus on low recoil energy KS/P1/Ge/ µ ν : . . . σ µ ∼ T − 1 • Sensitivity • decouples SM ”backround” Period II & III . . . ◮ Look for excess in Reactor ν e spectrum . . . ¯ ON/OFF Quenching factor [LE Reactor φ ( ¯ ν e ) not accurately Integral Spectrum known] Calibration data Summary ⋆ Neutrino Radiative Decay : (∆ m 2 ) 3 ◮ σ µ & Γ µ related : Γ= 1 µ ν 2 2 π m 3 ◮ real γ for same vertices � � � � � � � � �
OUTLINE KS/P1/Ge/ µ ν Data ν e Magnetic . . . ¯ Limits of . . . ν e e − → ¯ ν e e − . . . ♯ Data Volume : ¯ ◮ Total 4712/1250 hours ON/OFF KS Expt. : . . . KS Expt. : . . . ♯ HPGe Performance : µ ν with Reactor ¯ ν e ◮ 1.06 kg mass KS/P1/Ge/ µ ν Data ◮ 0.4 keV RMS at 10 keV Cosmic Veto, . . . ◮ 5 keV detector threshold Efficiency & . . . ◮ Background at O(1 cpd)[counts kg − 1 day − 1 keV − 1 ] KS/P1/Ge/ µ ν : . . . background c/f Dark Matter expt. Sensitivity ♯ Analysis : Period II & III . . . ◮ Cosmic veto ( 5 µs ) ν e spectrum . . . ¯ ◮ Anti-Compton (Well + Base detectors) Quenching factor ◮ Pulse Shape Disc. (rise time, fall time, amp. to charge ratio) Integral Spectrum Calibration data ♯ Efficiencied Normalization : (to < 0.2%) Summary ◮ DAQ book keeping → hardware status, deadtime ◮ Random Trigger → Eff. of Veto ◮ Stability of 40 K peaks ◮ Monitor 10 keV Ga X-rays peak � � � � � � � � �
OUTLINE Cosmic Veto, Anti-Compton & PSD ν e Magnetic . . . ¯ Limits of . . . ν e e − → ¯ ν e e − . . . ¯ KS Expt. : . . . KS Expt. : . . . µ ν with Reactor ¯ ν e KS/P1/Ge/ µ ν Data Cosmic Veto, . . . Efficiency & . . . KS/P1/Ge/ µ ν : . . . Sensitivity Period II & III . . . ν e spectrum . . . ¯ Quenching factor Integral Spectrum Calibration data Summary � � � � � � � � �
OUTLINE Efficiency & Uncertainties ν e Magnetic . . . ¯ Limits of . . . ν e e − → ¯ ν e e − . . . ¯ Event selection Suppression Efficiency KS Expt. : . . . Raw data 1.0 1.0 KS Expt. : . . . Anti-Compton (AC) 0.06 0.99 µ ν with Reactor ¯ ν e Cosmic-ray veto(CRV) 0.96 0.95 KS/P1/Ge/ µ ν Data Pulse shape analysis 0.86 1.0 Cosmic Veto, . . . Efficiency & . . . Combined efficiency 0.05 0.94 KS/P1/Ge/ µ ν : . . . Sensitivity Period II & III . . . ν e spectrum . . . ¯ σ ( κ 2 e )10 − 20 µ 2 Sources Uncertainties B Quenching factor DAQ live time ON/OFF < 0.2% < 0.30 Integral Spectrum Efficiencies for magnetic scattering < 0.2% < 0.01 Calibration data Rates for magnetic scattering 24% 0.23 Summary SM background subtraction 23% 0.03 Combined systematic error · · · < 0.4 � � � � � � � � �
OUTLINE KS/P1/Ge/ µ ν : Result ν e Magnetic . . . ¯ Limits of . . . ♯ Fit OFF spectra to p5 ν e e − → ¯ ν e e − . . . ¯ → [ φ OFF ; δφ OFF ] KS Expt. : . . . (@ χ 2 /dof = 80 / 96 ) KS Expt. : . . . µ ν with Reactor ¯ ν e ♯ Fit ON spectra to KS/P1/Ge/ µ ν Data φ OFF + φ SM + κ 2 φ MM [10 − 10 µ B ] Cosmic Veto, . . . Efficiency & . . . Fit Results : KS/P1/Ge/ µ ν : . . . (@ χ 2 /dof = 48 / 49 ) κ 2 = − 0 . 4 ± 1 . 3( stat . ) ± 0 . 4( sys . ) Sensitivity Period II & III . . . ν e spectrum . . . ¯ = ⇒ Limit : µ ν < 1 . 3(1 . 0) × 10 − 10 µ B Quenching factor @ 90(68)% C. L. Integral Spectrum Calibration data Summary H. B. Li et. al., TEXONO Coll., Phys. Rev. Lett. 90 , 131802(2003) � � � � � � � � �
OUTLINE Sensitivity ν e Magnetic . . . ¯ Limits of . . . ν e e − → ¯ ν e e − . . . ¯ ν e magnetic moment : ¯ KS Expt. : . . . KS Expt. : . . . µ ν with Reactor ¯ ν e At high σ ( µ ) /σ ( SM ) ratio : KS/P1/Ge/ µ ν Data → decouple from SM ”background” Cosmic Veto, . . . Efficiency & . . . KS/P1/Ge/ µ ν : . . . Sensitivity Period II & III . . . ν e spectrum . . . ¯ Quenching factor Integral Spectrum ν e decay constant : ¯ Calibration data Summary A better Γ ν limit than direct search. � � � � � � � � �
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