Neutrino and Dark Matter Physics with Quenching factor Integral - PowerPoint PPT Presentation

OUTLINE ν e N Coherent . . . ¯ ν e spectrum . . . ¯ Neutrino and Dark Matter Physics with Quenching factor Integral Spectrum an Ultra-Low-Energy Germanium Detector ULE-HPGe detector Calibration data Background . . . Low Energy Noise Plan : . . . Dark . . . WIMP . . . Plan : . . . Future Plan Summary NSYSU, Kaohsiung 2005 Feb 1 � � � � � � � � �

OUTLINE OUTLINE ν e N Coherent . . . ¯ ν e spectrum . . . ¯ Quenching factor ν e N Coherent Scattering ¯ ◮ Integral Spectrum ULE-HPGe detector ◮ LEGe Prototype Measurements with Sources Calibration data Background . . . ◮ Background Level at Exp. Site Low Energy Noise Plan : . . . ◮ Plan : Quenching Factor Measurement Dark . . . WIMP . . . ◮ Plan : Dark Matter Feasibility Studies Plan : . . . Future Plan ◮ Future Plans Summary ◮ Summary � � � � � � � � �

OUTLINE ν e N Coherent Scattering ¯ ν e N Coherent . . . ¯ ν e spectrum . . . ¯ Differential cross-section Quenching factor ν e e − → ¯ ν e e − scattering : ¯ Integral Spectrum [( g V − g A ) 2 + ( g V + g A ) 2 (1 − T E ν ) 2 + ( g 2 ULE-HPGe detector 2 m e ◮ ( dσ dt ) SM = G F V ) m e T A − g 2 ν ] 2 π E 2 Calibration data Background . . . dt ) MM = πα 2 µ 2 ◮ ( dσ e ( 1 1 T − E ν ) ν m 2 Low Energy Noise Plan : . . . Dark . . . ν e N → ¯ ¯ ν e N scattering : WIMP . . . 2 m N dt ) SM = G F [ Z (1 − 4 sin 2 θ W ) − N ] 2 [1 − M N T N ◮ ( dσ ν ] Plan : . . . 2 E 2 4 π → N 2 enhancement Future Plan Summary dt ) MM = πα 2 µ 2 ◮ ( dσ e Z 2 ( 1 1 T − E ν ) ν m 2 [ A. C. Dodd, et. al. Phys. Lett. B 266 434] 2 2 E ν ◮ Low recoil energy : T max = M N +2 E ν ( ∼ 1.9 keV for E ν = 8 MeV, Ge) � � � � � � � � �

OUTLINE ν e spectrum and Recoil e − , N Spectrum ¯ ν e N Coherent . . . ¯ ν e spectrum . . . ¯ Quenching factor Integral Spectrum ULE-HPGe detector Calibration data Background . . . Low Energy Noise Plan : . . . Dark . . . WIMP . . . Plan : . . . Future Plan Summary � � � � � � � � �

OUTLINE Quenching factor ν e N Coherent . . . ¯ ν e spectrum . . . ¯ Quenching factor = 0.25, ∆ E E ∼ 0.05 Quenching factor Integral Spectrum ULE-HPGe detector Calibration data Background . . . Low Energy Noise Plan : . . . Dark . . . WIMP . . . Plan : . . . Future Plan Summary At quenching factor = 0.25 : ∼ 0.05 count day − 1 keV − 1 at ∼ 140 eV. P1 data with HPGe : 0.05 count day − 1 keV − 1 below 10 keV for 5g. � � � � � � � � �

OUTLINE Integral Spectrum ν e N Coherent . . . ¯ ν e spectrum . . . ¯ For quenching factor = 1.0, 0.25, 0.5 Quenching factor Integral Spectrum ULE-HPGe detector Calibration data Background . . . Low Energy Noise Plan : . . . Dark . . . WIMP . . . Plan : . . . Future Plan Summary If threshold ∼ 100 eV → 0.055 count day − 1 (for 5 g, 11 count day − 1 for 1 kg) Signal to noise ratio in this energy range ∼ 2.2 � � � � � � � � �

OUTLINE ULE-HPGe detector ν e N Coherent . . . ¯ ν e spectrum . . . ¯ Quenching factor Integral Spectrum ULE-HPGe detector Calibration data Background . . . Low Energy Noise Plan : . . . ULE-HPGe target mass : 5 g Dark . . . WIMP . . . Plan : . . . Future Plan Summary shielding 4 π coverage ULE-HPGe with anti-compton � � � � � � � � �

OUTLINE Calibration data ν e N Coherent . . . ¯ ν e spectrum . . . Source : 55 Fe (5.9 keV, 6.49 keV) and Ti (4.51 keV, 4.93 keV) : ¯ Quenching factor Integral Spectrum Extrapolate energy calibration ULE-HPGe detector to low energy Calibration data Background . . . → threshold ∼ 60 eV. Low Energy Noise Plan : . . . Dark . . . WIMP . . . Plan : . . . Future Plan Summary Noise and signal are well seperater � � � � � � � � �

OUTLINE Background with ULE-HPGe ν e N Coherent . . . ¯ ν e spectrum . . . ¯ Compare period I HPGe data with ULE-HPGe : Quenching factor Integral Spectrum After scale to mass, ULE-HPGe data ULE-HPGe detector is 1 order larger then period I data, Calibration data with or without veto cut. Background . . . Low Energy Noise Plan : . . . Dark . . . WIMP . . . Plan : . . . Future Plan Summary Even the cosmic trigger event rate is 1 order different. → scale with surface? → need further simulation to clarify. � � � � � � � � �

OUTLINE Low Energy Noise ν e N Coherent . . . ¯ ν e spectrum . . . ¯ Quenching factor Integral Spectrum ULE-HPGe detector Calibration data Background . . . Low Energy Noise Plan : . . . Dark . . . WIMP . . . Plan : . . . Future Plan Peak at 100 eV → probably noise. Summary → a better PSD analysis is need. � � � � � � � � �

OUTLINE Plan : Quenching Factor Measurement ν e N Coherent . . . ¯ ν e spectrum . . . ¯ Quenching factor Integral Spectrum ULE-HPGe detector Calibration data Background . . . Low Energy Noise Plan : . . . Dark . . . WIMP . . . Plan : . . . Future Plan Last Quenching Factor Measuremen of Ge is 30 years ago. Summary Quenching Factor by using neutron beam at Institute of Atomic Energy, Beijing(CIAE). � � � � � � � � �

OUTLINE Dark Matter(WIMP) Experiment ν e N Coherent . . . ¯ ν e spectrum . . . ¯ Quenching factor Integral Spectrum ULE-HPGe detector Calibration data Background . . . Low Energy Noise WIMP detection : Plan : . . . Dark . . . ◮ passible mass range 1 GeV - 1 TeV. WIMP . . . Plan : . . . ◮ Typical nuclei recoil energy 0 - 100 keV. Future Plan ◮ expected background rate ∼ 1 cpd, or less. Summary Rate per recoil energy : = ρσ 0 | F ( q ) | 2 dR f ( � υ, t ) � d 3 υ. υ> √ 2 m W µ 2 dE r υ M N E r / 2 µ 2 � � � � � � � � �

OUTLINE WIMP detection with ULE-HPGe ν e N Coherent . . . ¯ ν e spectrum . . . ¯ Quenching factor Integral Spectrum ULE-HPGe detector Calibration data Background . . . Low Energy Noise Plan : . . . Dark . . . WIMP . . . Plan : . . . Future Plan Summary Low threshold → sensitive to low mass region. � � � � � � � � �

OUTLINE Plan : Background Measurement at Y2L ν e N Coherent . . . ¯ ν e spectrum . . . ¯ Quenching factor Integral Spectrum ULE-HPGe detector Calibration data Background . . . Low Energy Noise Plan : . . . Dark . . . Background measurement at Yang Yang Underground Lab(South Korea), WIMP . . . supported by KIM group. Plan : . . . Future Plan ◮ with 5 g ULE-HPGe Summary ◮ 700 m of rock. ◮ Cosmic-rays level → 5 order less. � � � � � � � � �

OUTLINE Future Plan ν e N Coherent . . . ¯ ν e spectrum . . . ¯ ◮ Quenching factor measurement at CIAE. Quenching factor Integral Spectrum ◮ Background measurement at Y2L. ULE-HPGe detector Calibration data ◮ Install 4 × 5 g array ULE-HPGe at power plant. Background . . . ◮ Understand the background level Low Energy Noise → simulation and PSD studies Plan : . . . Dark . . . ◮ Background and threshold studies with a 10 g ULE-HPGe. WIMP . . . ◮ Calibration at < keV, e − source generate X-rays from C, O. Plan : . . . Future Plan Summary � � � � � � � � �

OUTLINE Summary ν e N Coherent . . . ¯ ν e spectrum . . . ¯ ◮ explore potentials on ¯ ν e N coherent scattering Quenching factor → open window on low mass WIMP studies. Integral Spectrum ULE-HPGe detector ◮ preliminary result : Calibration data Background . . . → threshold ∼ 60eV - 120eV could be achieved Low Energy Noise → background level is 10 × of period I when scale by mass. Plan : . . . → trying to understand high background rate. Dark . . . WIMP . . . ◮ plans : Plan : . . . → prototype study on multi-array 4 × 5 g detector on site Future Plan → background level study on 10 g detector Summary → quenching factor with neutron beam exp at CIAE → background measurement at Y2L ◮ target : 1 kg multi-array ULE-HPGe detector → Dark Matter experiment → ¯ ν e N coherent scattering experiment � � � � � � � � �