Direct Search for Dark Matter

Transcription

1 Direct Search for Dark Matter Dark Matter Search Dark Matter in the Universe physics beyond the standard model how to detect Dark Matter particles Josef Jochum Eberhard Karls Universität Tübingen Kepler Center for Astro and Particle Physics

2 Dark Matter Search Standardmodel of Cosmology Dark Energy W vac = 73 % Dark Matter W mat = 23 % normal Matter W bar = 4% Standardmodel of Particle Physics expected from Standardmodel possible explanations beyond the Standardmodel 0 or or % % 0 % may be 4 % 0 % or % Physics beyond the Standardmodel at least one of the standards has to be changed (most likely both) (direct ) Dark Matter search is testing both exciting times

3 many astrophysical observations point to Dark Matter? Dark Matter Search orbital motion around Galaxies or motion of galaxies in galaxy clusters too fast gravity potential and distribution of visible matter do not coincide light deflection shows higher gravity potentials than expected from visible matter

4 Anisotropy of Comsic Microwave Background Dark Matter Search 2009 p + e - H + g 2001 Wilkinson Microwave Anisotropy Probe

5 p + e - Cosmic Microwave Background CMB Dark Matter Search H Universe not transparent Universe transparent Foto: Franko Fürstenhoff

6 CMB measurement perfect black body T = 2.73K Dark Matter Search tiny anisotropy ~ dt / T ~ 10-5 shows density variation at (re)-combination p + e - H + g CMB: t = years z = 1100 ; T ~ 3000K; kt ~ 0,3 ev Universe was 1100 times smaller scale factor: R = 1 today, R = 1 / 1100 at (re)-combination

7 Dark Matter Search Power Spectrum compression and decompression peaks shows the oscillation modes which are at maximum compression or maximum expansion at the time of (re)combination

8 did this anisotropy grow to todays structure? Dark Matter Search

9 Structure Formation in the Universe density r; pressure p, speed v, gravity potential F Dark Matter Search continuity eq. for small disturbance Euler eq. wave eq with gravity Poisson eq. - densitiy only oscillates - no structure growth as long as pressure term is large >

10 Structure Formation in the Universe density r; pressure p, speed v, gravity potential F Dark Matter Search wave eq with gravity pressure term pressure comes from kinetic energy relativistic particles radiation non-relativistic particles pressure 0 no pressure no structure growth - before (re)-combination p + e - => H + g (cosmic microwave background) - as long as particles are relativistic kt > mc 2

11 Structure Formation in the Universe Dark Matter Search no structure growth - before (re)-combination p + e - => H + g (comsic microwave background) - as long as particles are relativistic kt > mc 2 d (re) combination, CMB t pressure vanishes

12 Structure Formation in the Universe Dark Matter Search R: scalefactor if defined =1 today, was 1/1000 at (re)combination) once density contrast d grows, it grows like the scale factor d ~ R ~ 1/T d x 1000 since (re)combination today 2,7K recomb ~ 3000 K

13 observed anisotropy of 10-5 by far too small Dark Matter Search 10-5 x was there a 100 x larger anisotropy we cannot see in the CMB? if yes, then made out of particles without electromagnetic interaction otherewise we would see it in CMB Dark Matter

14 Structure Formation in the Universe Dark Matter Search d (re) combination, CMB t the only non electromagnetic particles in the standard model are Neutrinos BUT: Neutrinos still relativistic at (re)combination ( kt ~ 0,3 ev ) cannot form structure => dark matter is made out of beyond SM particles

15 Dark Matter Search compression peaks stronger expansion peaks weaker charged particles (p, e - ) oscillate in a background non-oscillating gravity field => neutral particles, which started structure formation much earlier => physics beyond standard model of particle physics

16 Dark Matter Search compression peaks stronger expansion peaks weaker here you see dark matter by naked eye charged particles (p, e - ) oscillate in a background non-oscillating gravity field => neutral particles, which started structure formation much earlier => physics beyond standard model of particle physics

17 weakly interacting heavy ( > ~ kev) Dark Matter Search many ideas : pu? sterile kev neutrinos Axions Supersymmetry. d e -?? 100 GeV - ~ 1000 GeV mass range is quite natural accelerator bounds thermodynamics during big bang Supersymmetry or ~ 5GeV n e? if it shares matter-antimatter asymmetry ( m c ~ W DM / W p,n * m p ) new particles beyond the standard model WIMP weakly interacting massive particle

18 make it WIMP direct production at LHC? Dark Matter Search on land? Large Hadron Collider CERN - Genf??

19 Dark Matter Search brake it WIMP indirect search - neutrino telescopes - WIMP over density in earth, sun, galactic center c search for high energy annihilation products e.g. high energy neutrinos from sun n m m c c c c c c

20 Neutrino Teleskope Dark Matter Search ICECUBE at south pole m Neutrino durchdringt die Erde charged current reaction kurz vor dem Detektor aufsteigende Muonen (nur durch Neutrinos machbar) Richtung und Energie des Neutrinos Neutrino Astronomie ANTARES, KM3Net In the mediterranean

21 in ice WIMP Indirect Search - Neutrino Telescopes - Dark Matter Search ICECUBE at south pole m SuperK upward muons ANTARES, KM3Net In the mediterranean in water

22 WIMP indirect search gamma-telescopes and anti-matter Dark Matter Search g-ray telescopes: CTA, HESS, MAGIC,... g-ray satellites: FERMI... GLAST in space Search for high energy annihilation products e.g. high energy gammas from galactic center search for anti-matter from annihalation Antimatter (Anti-Deuteron) Searches: AMS, PAMELA,...

23 shake it WIMP direct detection by elastic scattering off nuclei Dark Matter Search

24 Underground laboratories for rare event searches Dark Matter Search WIMP search in the underground CRESST experiment TU München Max Planck Physik München Uni Tübingen Gran Sasso Labor shielding 1.5km rock

25 WIMP Direct Detection Weakly Interacting Massive Particles = WIMPs Elastic Scattering off Nuclei Nuclear Recoils: reduced efficiency for charge- or light-production - Mass GeV - ~ 1000 GeV - relative speed 270 km/s ( ~ orbital speed in Milky Way) c only a few kev of energy - cross section - local WIMP-Density s c < cm 2 r c 0.3 GeV / cm 3 - corresp. 3 WIMPs (100GeV) / Liter /s /cm 2 very very rare scattering events(< 1 / Week / kg) Today s sensitivity < 1 / year / kg

26 Particle Identification by Combination of Channels cryogenic charge / phonon cryogenic light / phonon CDMS, EURECA radioactive background can be rejected => highly improved sensitivity EURECA liquid noble gas light / charge WARP, ArDM, LUX, ZEPLIN

27 Liquid Noble Gases Background Rejection by Light vs. Charge WIMP GAMMA NUCLEAR RECOIL ELECTRON

28 no indication for WIMP signal Liquid XENON Charge + Light Background XENON kg target, 58.6 kgd exposure 10 background events ~1 cts / 6 kgd astro-ph: WIMP Region Background WIMP Region XENON kg ~2500 kgd 2 target, exposure background events ~ 1 cts / 1500 kgd, ~ 1 cts/ 4 kg years g bckgrnd ~ 250 x lower PRL Background LUX kg ~10000 kgd <1 ~ 1 cts/ 25 kg years g bckgrnd ~ again 25 x lower target, exposure background events PRL 112, astro-ph: v2 WIMP Region large improvement on sensitivity

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32 Direct DM Searches low WIMP masses: - low energy threshold - moderate target masses - cryogenic detectors high WIMP masses: - large targets - moderate energy threshold - liquid noble gas (Xenon) detectors CRESST (2002) 100

33 Liquid Noble Gases (near) future XENON (European, US,..) XENON100, 50kg fid vol. expect new data XENON 1t (3,3t in total) running since 2016 presently best limits 7.7*10-47 cm 35 GeV LUX + ZEPLIN: LZ (US, European,..) 7t Xe approved by NSF & DoE Dark LNGS (Italy, US,..) funded: 1 t depleted LAr DEAP (Canada, US, ) 1-phase, SNOLAB 1000 kg fid. running

34 Direct DM Searches low WIMP masses: - low energy threshold - moderate target masses - cryogenic detectors high WIMP masses: - large targets - moderate energy threshold - liquid noble gas (Xenon) detectors CRESST (2002) 100

35 Direct DM Searches low WIMP masses: - low energy threshold - moderate target masses - cryogenic detectors high WIMP masses: - large targets - moderate energy threshold - liquid noble gas (Xenon) detectors CRESST (2002) 100

36 Cryogenic Experiments Phonon + Light or Phonon + Charge Thermometer c CRESST II - Detectors simultaneous Light and Phonon Thermometer Absorber CaWO 4 Phonon-Detector Licht Detector (low T calorimeter) reflecting foil CRESST Cryogenic Rare Event Search with Superconducting Thermometers Max-Planck-Institut München, TU München Universität Tübingen, Oxford University, Gran Sasso

37 Cryogenic Experiments Phonon + Light or Phonon + Charge SuperCDMS CRESST II - Detectors Cryogenic Dark Matter Search simultaneous Light and US Kollaboration Phonon Thermometer c Charge+ Phonon (semiconductor Ge, Si) Thermometer EDELWEISS Experience pour DEtecter Les Wimps En SIte Souterrain France and Germany Absorber CaWO 4 Phonon-Detector Charge + Phonon (semiconductor Ge) Licht Detector (low T calorimeter) reflecting foil CRESST Cryogenic Rare Event Search with Superconducting Thermometers Max-Planck-Institut München, TU München Universität Tübingen, Oxford University, Gran Sasso

38 Cryogenic Experiments Phonon + Light or Phonon + Charge calorimeter arrays module masses 20g 1400g thermometers: superconducting phase transition or highly doped semiconductors low energy threshold => good at low WIMP masses SuperCDMS approved by NSF & DOE at SNOLAB installation for 400kg target present funding for 50kg start ~ 2020 EDELWEISS 36 x 800g Ge detectors at LSM CRESST 18 x 300g CaWO 4 detectors at LNGS since x 24 g lower threshold even better at low WIMP mass lowest threshold leading at low WIMP masses

39 Cryogenic Experiments SNOLab approved by NSF & DOE, ~2020 presently CRESST leading at low WIMP masses probe higher WIMP masses in case of a positive detection with a multi element target CaWO 4, Ge, Si, potential to reach solar neutrino sensitivity

40 Direct Dark Matter Search (near) future 1t scale liquid Xenon detectors running XENON 1t LZ coming Cryogenics: EDELWEISS and CRESST continue running SuperCDMS funded worldwide cooperation sensitivity at low and high WIMP masses will improve in case of discovery: good possibilities for multitarget confirmation might turn into neutrino detection

41 LHC DM Searches spin independent interaction spin dependent interaction

42 IceCube (indirect) DM Searches spin dependent interaction

43 Neutrinos there are 336 neutrinos / cm -3 left from Big Bang could be a considerable contribution to Dark Matter 100% of dark matter if ~ 10 ev

44 Neutrinos d (re) combination, CMB t the only non electromagnetic particles in the standard model are Neutrinos BUT: Neutrinos still relativistic at (re)combination ( kt ~ 0,3 ev) cannot form structure

45 Neutrinos there are 336 neutrinos / cm -3 left from Big Bang could be a considerable contribution to Dark Matter 100% of dark matter if ~ 10 ev but: they are too light look at structure in the Universe to get limits on

46 Neutrinos

47 Neutrinos Why not Neutrinos? W matter ~ 0.30 W n < 0.02 W < 0.02 n mn i < 0.6 ev

48 Standardmodel of Cosmology Dark Energy W vac = 73 % Dark Matter W mat = 23 % normal Matter W mat = 4% Standardmodel of Particle Physics expected from Standardmodel possible explanations beyond the Standardmodel 0 or or % % 0 % may be 4 % 0 % or % Physics beyond the Standardmodel at least one of the standards has to be changed (most likely both) (direct ) Dark Matter search is testing both exciting times