Direct Neutrino Mass Measurements

Transcription

1 Direct Neutrino Mass Measurements KITP, 11/3/2014

2 Neutrino mass Upper bound from direct measurements Lower bound from oscillation experiments 2

3 Neutrino mass Cosmology model-dependent potential: Σm i = mev e.g. Planck Search for 0νßß model-dependent potential: m ßß = mev e.g. MAJORANA Kinematics of ß-decay model-independent potential: m ν = 200 mev e.g. KATRIN 3

4 Neutrino mass Knowledge of neutrino mass has an impact on both particle physics and cosmology 4

5 Neutrino mass Current limits Neutrinos excluded as Dark Matter 5

6 Neutrino mass Current limits Next goal of future experiments Neutrinos excluded as Dark Matter Distinquish between hirarchical and degenerate scenario, impact on structure formation 6

7 Neutrino mass Current limits Next goal of future experiments New ideas Neutrinos excluded as Dark Matter Distinquish between hirarchical and degenerate scenario, impact on structure formation Resolve neutrino mass hierarchy 7

8 General Idea A kinematic determination of the neutrino mass No model dependence on cosmology or nature of mass 8

9 3 Experimental Efforts Drexlin, Susanne V. Hannen, Mertens S. M., C. Weinheimer, Adv. High Energy Physics 2013, Article ID , (2013) 9

10 3 Experimental Efforts Spectroscopy (KATRIN) 10

11 3 Experimental Efforts Spectroscopy (KATRIN) Calorimetry (HOLMES, ECHO &NUMECS) 11

12 3 Experimental Efforts Spectroscopy (KATRIN) Calorimetry (HOLMES, ECHO &NUMECS) Frequency (Project 8) 12

13 Karlsruhe Tritium Neutrino Experiment International Collaboration: 120 members 15 institutions in 5 countries: D, US, UK, CZ, RUS Reference ν-mass sensitivity: m(ν e ) = 200 mev, after 3 years 13

14 KATRIN Overview Windowless Gaseous Molecular Tritium Source 14

15 KATRIN Overview Differential and Cryogenic Pumping system 15

16 KATRIN Overview Spectrometer system 16

17 KATRIN Overview 17

18 KATRIN Overview Detector system 18

19 : Arrival of Main Spectrometer in Karlsruhe

20 2011: fully commissioned Aircoil system 20

21 January 2012: Inner electrode system ( wires) completely mounted (precision: 200 µm!) 21

22 May 8, :11 spectrometer pump ports are closed 22

23 Commissioning of main spectrometer Successful bake-out of spectrometer vessel at 300 C Inner electrode system: no broken wire NEG pump activated: pressure at 5x10-11 mbar First light last summer 23

24 Commissioning of main spectrometer Successful bake-out of spectrometer vessel at 300 C Inner electrode system: no broken wire NEG pump activated: pressure at 5x10-11 mbar First light last summer 24

25 Commissioning of main spectrometer Transmission Properties Background Rates Transmission probability Measurement Monte Carlo Background rate mean total rate: 0.78 ± 0.20 cps WARM BAFFLES COLD BAFFLES mean total rate: 0.47 ± 0.09 cps E start - qu AP Spectrometer transmits electrons as expected! Radius in analyzing plan (m) Background rate of order Hz (10 mhz desired). Greater reduction of backgrounds to come 25

26 Commissioning of main spectrometer Background Rates Background rate mean total rate: 0.78 ± 0.20 cps WARM BAFFLES COLD BAFFLES mean total rate: 0.47 ± 0.09 cps Radius in analyzing plan (m) Background rate of order Hz (10 mhz desired). Greater reduction of backgrounds to come 26

27 KATRIN and sterile neutrinos 1 v 2 3 τ e v µ v New mass eigenstate 27

28 KATRIN and sterile neutrinos Active-to-sterile mixing amplitude Mass of the sterile neutrino 28

29 KATRIN and sterile neutrinos ev-sterile neutrinos Active-to-sterile mixing amplitude Mass of the sterile neutrino 29

30 KATRIN and sterile neutrinos kev-sterile neutrinos Active-to-sterile mixing amplitude Mass of the sterile neutrino 30

31 KATRIN and sterile neutrinos Upgraded KATRIN provides interesting statistical sensitivity to astrophysically allowed region for dark matter sterile neutrinos S. M. et Susanne al, arxiv: , Mertens (2014) S. M. et al, arxiv: , (2014) 31 KATRIN as is probes the favored parameter space for light sterile neutrinos J. A. Formaggio, J. Barret, PLB 706 (2011) 68 A. Esmaili, O.L.G. Peres, Phys. Rev. D 85, A. Sejersen Riis, S. Hannestad, JCAP02 (2011) 011

32 3 Experimental Efforts Spectroscopy (KATRIN) Calorimetry (HOLMES, ECHO &NUMECS) Frequency (Project 8) Drexlin, Susanne V. Hannen, Mertens S. M., C. Weinheimer, Adv. High Energy Physics 2013, Article ID , (2013) 32

33 Electron Capture on Holmium Ho Dy * Dy * + ν e Dy + E EC Atomic de-excitation: X-ray emission Auger electrons Calorimetric measurement Coster-Kronig transitions 33

34 Electron Capture on Holmium Neutrino signature Endpoint: kev Half live: 4500 years 34

35 Calorimetric measurement Advantages: Source = detector All energy is detected No molecular final states Self-calibrating Challenges: ΔE FWHM < 10 ev τ risetime < 1 μs to avoid background due to pile-up Sufficient isotope production 35

36 Calorimetric measurement Advantages: Source = detector No backscattering No molecular final states Self-calibrating Challenges: decays in 1 year With 100 Bq per pixel 10 5 detectors ΔE FWHM < 10 ev τ risetime < 1 μs to avoid background due to pile-up Sufficient isotope production 36

37 The Echo Experiment Heidelberg (Univ., MPI-K), U Mainz, U Tübingen, TU Dresden U Bratislava, INR Debrecen, ITEP Moscow, PNPI St Petersburg, IIT Roorkee, Saha Inst. Kolkata Metallic magnetic calorimeters (MMC) Fast rise times (τ = 130 ns), good energy resolutions (7.6 6keV), and linearity demonstrated Microwave Multiplexing techniques (RF-SQUID) Paramagnetic sensor 30 mk 37 A. Fleischmann et al., AIP Conf. Proc. 1185, 571, (2009) L. Gastaldo et al., Nucl. Inst. Meth. A, 711, (2013) P. C.-O. Ranitzsch et al., JLTP 167, 1004 (2012) S. Kempf et al, JLTP /s

38 The Holmes Experiment U Milano-Bicocca, INFN Milano/Genova/Roma, U Lisboa, U Miami, NIST, JPL Transition-Edge Sensors (TES) Microwave Multiplexing with Kinetic Inductance Detectors (MKIDs). Successful funding received for one thousand channel Ho detector experiment 38 M. Ribeiro Gomes et al., IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, VOL. 23, NO. 3, JUNE 2013

39 The NuMecs Experiment Los Alamos, NIST, U Madison and others Transition-Edge Sensors (TES) Good energy resolution (6 6 kev with 55Fe surrogate). Concentration on high purity 163 Ho production proton activation of dysprosium 55Fe spectrum Show scalability through a demonstrator experiment with 4 x 1024 TES array of Ho-implanted detectors with RF-SQUID multiplexing 39 J.W. Engle et al. NIM B 311 (2013) Nu_Project8.pdf

40 3 Experimental Efforts Spectroscopy (KATRIN) Calorimetry (HOLMES, ECHO &NUMECS) Frequency (Project 8) Drexlin, Susanne V. Hannen, Mertens S. M., C. Weinheimer, Adv. High Energy Physics 2013, Article ID , (2013) 40

41 Project 8 Use cyclotron frequency to extract electron energy Non-destructive measurement of electron energy UW/Seattle, MIT, UC/Santa Barbara Yale, Pacific NW, Livermore, NRAO, KIT 41 B. Monreal and Joe Formaggio, Phys. Rev D80:051301

42 Project 8 Setup 42

43 Test measurement with Krypton 43

44 First electron detection 44

45 First electron detection Electron scatters of gas, losing energy and changing pitch angle Energy loss increases frequency Onset frequency yields initial kinetic energy 45

46 First electron detection FWHM ~ 140 ev 46 /

47 Future perspective of Project 8 Scattering limit FSD limit 47 gov/fsnufiles/positionpap ers/fsnu_project8.pdf

48 Joining efforts KATRIN selects the electrons. and Project 8 measures their energy 1) Trigger the electron close the trap 2) Measure the energy 48

49 Summary In 2016 KATRIN will start neutrino mass measurements and will probe the entire degeneracy scale Cryogenic techniques are advancing to achieve the sub-ev sensitivity Project 8 proved a completely new concept via frequency measurement. Very promising to reach sub-ev sensitivity 49

50 Thanks for your attention 50

51 KATRIN Backup slides 51

52 First Transmission Measurement angular selective egun PRELIMINARY 52

53 First Background Measurement PRELIMINARY Desired background rate: 10 mcps Initial measured rate: 1 cps 53

54 Radon-induced Background 54

55 Radon-induced Background Getter pump t 1/2 ( 219 Rn) = 3.96 s t 1/2 ( 220 Rn) = 55.6 s 55

56 Radon-induced Background 56 N. Wandkowsky et al., New J. Phys. 15 (2013) N. Wandkowsky et al., J. Phys. G 40 (2013) 8 S. M. et al., Astropart. Phys. 41 (2013) 52

57 Passive Reduction Technique Rate (cps) WARM BAFFLES COLD BAFFLES Radius (m) Getter pump LN2 cooled baffle 57

58 Cosmic muon induced Background e Magnetic shielding 58 Electric shielding

59 Effect of wire electrode PRELIMINARY 59

60 Signature of ev neutrinos 60

61 KATRIN - summary KATRIN is designed to reach a sensitivity of 200 mev (90%CL) after 3 years of measurement time Successful commissioning of main spectrometer Next measurement phase began last week Start of Neutrino mass measurements 2016 Promising potential to search for ev to kev sterile neutrinos in a model-independent way 61

62 Holmium backup slides 62

63 ECHo: First Setup 63

64 ECHo: First Setup Absorber Source Meander

65 ECHo: Some details 100 pixel with Bq per pixes Neutrino activation of erbium 162, purification and mass separation, implantation

66 Project 8 backup slides 66

67 Simulated tritium frequency spectrum 67

68 Future Perspectives 68