Presentation is loading. Please wait.

Presentation is loading. Please wait.

DARK MATTERS AND NEUTRINO PROJECTS AT THE CENTER FOR UNDERGROUND PHYSICS. AKPA Yeongduk Kim Center for Underground Physics, IBS Sejong University 2014.

Similar presentations


Presentation on theme: "DARK MATTERS AND NEUTRINO PROJECTS AT THE CENTER FOR UNDERGROUND PHYSICS. AKPA Yeongduk Kim Center for Underground Physics, IBS Sejong University 2014."— Presentation transcript:

1 DARK MATTERS AND NEUTRINO PROJECTS AT THE CENTER FOR UNDERGROUND PHYSICS. AKPA Yeongduk Kim Center for Underground Physics, IBS Sejong University

2 2 Center for Underground Physics (CUP)  CUP began on July 2013 as a headquarter center.  Now, 17 Ph.Ds, 15 students, 3 technicians, 2 administrations.  Research Area : Dark Matter, Double Beta Decay, Sterile neutrino search, Low temperature Detector Development.

3 3 Evidences for Dark Matter Existence

4 4 More quantitative evidence : cosmic microwave background

5 5 Particle candidates Many particle candidates are proposed with many orders of magnitude of mass. Who will be the hero ? Or None of them. K.Y. Choi, JKPS 63, 1685(2013)

6 6 Weakly Interacting Massive Particle (WIMP) WIMP is a massive new particle having a right value for the current dark matter density. So it is a good candidate for dark matter particles. increasing

7 7 WIMP DETECTION  qq Annihilation (Indirect Search) WIMP scattering (Direct Search) Production (Accelerator Search) WIMP

8 8 Detection Principle of Direct Search Detector WIMP Nucleus WIMP-Nucleus elastic scattering Event rate : Experiment Measure this SUSY models Limit of R  Limit of 

9 9 What is the direct signal for WIMPs ? 1.Recoil energy spectrum as expected at low energy. 2.Annual modulation. 3.Directional asymmetry. 4.A 2 dependence (Spin-independent) Earth velocity (30km/s) Yearly revolution  annual modulation Daily rotation  direction change

10 kg NaI(Tl) crystals coupled with PMTs. Observed clear annual modulation for 13 years. PMT +HV divider DAMA/LIBRA experiment

11 11 Status of WIMP searches

12 YangYang Pumped Storage Power Plant YangYang(Y2L) Underground Laboratory Minimum depth : 700 m / Access to the lab by car (~2km) (Upper Dam) (Lower Dam) (Power Plant) KIMS (Dark Matter Search) AMoRE (Double Beta Decay Experiment) Seoul Y2L 700m 1000m RENO

13 13 KIMS-NaI CUP To verify the DAMA result using same NaI(Tl) crystals. Our strategy : Achieve lower background level and lower energy threshold than DAMA by factor 2. We can clarify the origin of the annual modulation unambiguously. NaI(Tl) Crystal CsI Detector

14 14 Background rates – We are getting there. Low threshold down to 1 keV is possible. Background reduction expected by further purification.

15 Search for Neutrinoless Double Beta Decays Ettore Majorana (1906 – 1938 ?)

16 16 Neutrino mixing & oscillation 16 If neutrinos are massive and mixed, then they oscillate. 0 0

17 17 Neutrino mixing & oscillation 17 Survival Probability PRL100, (2008)

18 18 Search for Neutrinoless double beta decay (0  ) Observation of 0  will prove 0  event 0  event

19 19 Neutrino mass from 0  experiment Half-lifves of 0  inversely proportional to mass 2 Half-life Measured Neutrino Mass

20 Moore’s law for   lliott & Vogel, Ann, Phys. (2002) 76 Ge, Gerda (0.3) Xe, EXO (0.26) Xe, KAMLAND-ZEN (0.19)

21 21 Overview of AMoRE-200kg Scintillating Bolometer : 40 Ca 100 MoO 4 + MMC CaMoO 4 Light sensor MMC phonon sensor AMoRE-200 is the most massive experiment with enriched isotope having Q value > 3MeV. 216 g

22 22 MMC (Metallic Magnetic Calorimeter) paramagnetic sensor: Au:Er

23 23 Energy resolution data CaMoO 4 (natural) with a phonon sensor only. FWHM = 9 keV, Goal = 5 keV

24 24 Crystal Growing Facility Motivation : difficulty to find a reliable and economical company. Will develop chemical purification and crystallization ourself inside the center. (4 furnaces)

25 25 Races for 0 

26 Thank you !

27 27 Dark Matter GroupNew Detector GroupLow Temp. Detector GroupDouble Beta Decay GroupNuclear Astrophysics Group Director Y2L KT1 LAB Simulation Team SBL Team KIMS-NaI Team Advisory Committee Underground Lab Preparation Team Administration KRISS Samcheok City KIMS Collaboration New Physics Team Adjunct group AMoRE Collaboration Organization of CUP

28 28 Weakly Interacting Massive Particles (WIMP) 이휘소, 와인버거 박사의 1977 논문 “Cosmological Lower Bound on Heavy-Neutrino Mass” ( 무거운 중성미자 질량에 대한 우주론적인 하한값 ) 암흑물질의 후보로서의 약하게 상호작용하는 윔프와 같은 무거운 입자의 가능성을 거론. 빅뱅이후 약하게 상호작용 하는 안정적인 입자가 생성 되어 Freeze out 되어 남게 되면 Dark Matter 가 될수 있다. M(wimp)>2GeV

29 29 2 Jun. Time Background Level KIMS-CsI annual modulation data 12 crystals (104.4kg). 2.5 year data (Sep. 2009–Feb. 2012) Background Level : 2~3 cpd/kg/keV The mean amplitude from 3 keV to 6 keV is ± cpd/kg/keV

30

31 31 Comparison with Direct Search

32 32 PMT noise reduction in background data. DAMA/LIBRA reported PMT noise reduction by introducing charge ratio parameters. KIMS-NaI obtained the same results as DAMA. X1 X2 X1 X2 DAMA, E=2-4 keVKIMS-NaI, E=2-4 keV PMT noise Real signals

33 33 Q|fermion> = |boson> particle  super particle R parity = 1 for ordinary particles = -1 for SUSY partners If R parity is conserved, LSP ( Lightest SUSY Partner) will be stable and a strong candidate of WIMP. Supersymmetric particles

34 AMoRE 10 AMoRE 200 Effective Neutrino mass (eV) Lightest neutrino mass (eV) Toward lower neutrino mass

35 35 Pulse Shape Discrimination Muon Gamma Alpha  and  events show different pulse shapes in phonon signals. Beta-Alpha

36 36 Phonon sensor for AMoRE Gold film We measure both thermal and athermal phonons. Phonon collector Patterned gold film Gold wires (thermal connection) MMC rise-time: ~ 0.5ms 216 g CaMoO 4


Download ppt "DARK MATTERS AND NEUTRINO PROJECTS AT THE CENTER FOR UNDERGROUND PHYSICS. AKPA Yeongduk Kim Center for Underground Physics, IBS Sejong University 2014."

Similar presentations


Ads by Google