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Hmotná neutrina Vít Vorobel, ÚČJF MFF UK

Hmotná neutrina Vít Vorobel, ÚČJF MFF UK. Úvod (milníky, pojmy) Kinematická měření m n Oscilace neutrin (mixování neutrin) Dvojný beta-rozpad (Majorana x Dirac ?) Experiment NEMO-3 – dvojný beta-rozpad Experiment SuperNEMO Experiment Daya Bay – oscilace reaktorových antineutrin.

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Hmotná neutrina Vít Vorobel, ÚČJF MFF UK

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  1. Hmotná neutrinaVít Vorobel, ÚČJF MFF UK • Úvod(milníky, pojmy) • Kinematická měření mn • Oscilace neutrin (mixování neutrin) • Dvojný beta-rozpad (Majorana x Dirac ?) • Experiment NEMO-3 – dvojný beta-rozpad • Experiment SuperNEMO • Experiment Daya Bay – oscilace reaktorových antineutrin Seminář ÚČJF - Vít Vorobel

  2. Neutrinové milníky • 1930 Pauli – neutrální částice v b-rozpadu • 1937 Majorana – co když n = anti-n ? • 1956 Reines, Cowan – pozorování reaktorových anti-n • 1957 Pontecorvo – hypotéza oscilací neutrin • 1968 Davis – pozorování slunečních n (deficit) • množství experimentů a trpělivost • 1998 Super-Kamiokande – pozorování oscilací atmosférických n • ................................................................................. • 80 let poté • 2010 Hierarchie? Majorana? Hmotnost? Proč tak malá? ... Seminář ÚČJF - Vít Vorobel

  3. Základní formalizmus - mísení neutrin • Slabé stavy • Hmotnostní stavy • Směšovací matice Pontecorvo-Maki-Nakagawa-Sakata • Informace o hmotnosti neutrin (9 parametrů) • Hmotnosti (3) • Parametry PMNS matice • Směšovací úhly (3) • Diracova fáze (1) • Majoranovy fáze (2) Seminář ÚČJF - Vít Vorobel

  4. Kinematická měření . • Beta – rozpad3H • Mainz, Troick, mne < 2 eV/c2 • KATRINE, plánovaná citlivost 0.2 eV/c2 • Rozpad p – PSI, mnm < 170 keV/c2 • Rozpad t – OPAL, DELPHI,ALEPH • mnt < 18 MeV/c2 Seminář ÚČJF - Vít Vorobel

  5. Oscilace neutrin . • Oscilace ve vakuu - Pontecorvo 1957 • 2 neutrina: oscilační délka • Oscilace v hmotném prostředí - Wolfenstein 1978, Mikheyev-Smirnov 1985 (MSW effect) • významný efekt pro sluneční a urychlovačová neutrina • Z0 : ne, nm, nt • W+: pouze ne • Efektivní mi jsou jiná v prostředí než ve vakuu Seminář ÚČJF - Vít Vorobel

  6. bb-rozpad (A,Z)(A,Z+2) + 2e- + 2n (A,Z)(A,Z+2) + 2e- 0: proces mimoSM, T1/2 1025y 2: proces dovolený v SM, T1/2 ~ 1020y Seminář ÚČJF - Vít Vorobel

  7. NEMO-3/SuperNEMO collaboration Neutrino Ettore Majorana Observatory (Neutrino Experiment on MOlybdenum – historical name) 80 physicists / 30 institutions Seminář ÚČJF - Vít Vorobel

  8. 0nbb and neutrino fundamental properties Probe of neutrino nature. Neutrinos are Majorana fermions (particle  antiparticle) if 0 takes place  See-Saw mechanism, Leptogenesis, Baryon asymmetry, CP violation Neutrino mass hierarchy. 0 measurements might help to establish the right one. Absolute mass scale. 0 experiments are among the most sensitive ones. Spreads are due to variations of unknown CP phases Seminář ÚČJF - Vít Vorobel

  9. B(25 G) 3 m Magnetic field: 25 Gauss Gamma shield: Pure Iron (18 cm) Neutron shield: borated water (~30 cm) + Wood (Top/Bottom/Gaps between water tanks) 4 m The NEMO3 detector Fréjus Underground Laboratory : 4800 m.w.e. 20 sectors Source: 10 kg of  isotopes cylindrical, S = 20 m2, 60 mg/cm2 Tracking detector: drift wire chamber operating in Geiger mode (6180 cells) Gas: He + 4% ethyl alcohol + 1% Ar + 0.1% H2O Calorimeter: 1940 plastic scintillators coupled to low radioactivity PMTs Able to identify e-, e+, g and a-delayed Seminář ÚČJF - Vít Vorobel

  10. NEMO3 unique features Multi-source detector Multisourcebb-detector Measurement of full bb-event pattern Self-determination of ALL background components measuring independent channels Seminář ÚČJF - Vít Vorobel

  11. 100Mo 2 Results Sum energy spectrum Single electron energy spectrum Angular distribution 100Mo • • Data • MC ββ2 • background • subtracted NEMO-3 ’’2n-factory’’ in action 100Mo 100Mo 219 000 events 389 days S/B=40 Unique spectra from tracko-calo technique Latest results: Seminář ÚČJF - Vít Vorobel

  12. 100Mo 2 Results Summary of NEMO-3 2n-results Systematic studies of 2nbb process provide crucial knowledge for 0nbb search!

  13. 100Mo 2 Results 0n-results

  14. From NEMO to SuperNEMO NEMO-3 successfulexperienceallows to extrapolatetracko-calo technique on larger mass nextgeneration detector to reach new sensitivitylevel. SUPERNEMO R&D is in progress since 2006

  15. SuperNEMO basic design SuperNEMO module 20 modules, each of them hosts: - 5 kg of source foil (82Se, 40mg/cm2) - 2000-3000 Geiger channels - 600 Calorimeter channels: PVT Scintillator + 8’’ PMT SuperNEMO is the favorite project to be hosted in the new LSM laboratory (hall A) planned to be opened at 2013

  16. SuperNEMO demonstrator Source: 6.3 kg of 82Se Tracker R&D Calorimeter R&D Simulations Low background R&D BiPo setup • SuperNEMO demonstrator (first module) being finalizing, which will: • Prove the concept • Test 0nbb at level of KGC • Start in 2012

  17. Aktivity MFF UK v NEMO-3/SuperNEMO • V úzké spolupráci s UTEF ČVUT • NEMO-3 • Simulace a návrh neutronového stínění • Koordinace výroby/dodávky nosné konstrukce detektoru (Transporta Chrudim) • Koordinace výroby/dodávky „Radon Trapping Facility“ (Hradec Králové) • Analýza dat 150Nd (excitovaný stav) • SuperNEMO • Studie alternativní podoby kalorimetru (PD x PMT) • Optimalizace tvaru scintilátorů • Měření Rn • Testování scintilátorů BiPo setup Seminář ÚČJF - Vít Vorobel

  18. Scintillator response vs irradiation position Peak position, ADC Scintillator position scan Irradiated area 11.6 mm FWHM @ 1 MeV, % 91.5 88.6 85.5 20 mm 20 mm 11.8 13.8 14.1 87.3 88.7 91.9 13.9 12.7 11.5 89.9 90.6 92.5 13.7 11.9 12.5 NEMO3/SuperNEMO collaboration meeting, Prague

  19. Daya Bay Reactor Antineutrino Oscillation Experiment Seminář ÚČJF - Vít Vorobel

  20. Europe (3) (9) JINR, Dubna, Russia Kurchatov Institute, Russia Charles University, Czech Republic North America (14)(54) BNL, Caltech, George Mason Univ., LBNL, Iowa state Univ. Illinois Inst. Tech., Princeton, RPI, UC-Berkeley, UCLA, Univ. of Houston, Univ. of Wisconsin, Virginia Tech., Univ. of Illinois-Urbana-Champaign Asia (18) (88) IHEP, Beijing Normal Univ., Chengdu Univ. of Sci. and Tech., CGNPG, CIAE, Dongguan Polytech. Univ., Nanjing Univ.,Nankai Univ., Shandong Univ., Shenzhen Univ., Tsinghua Univ., USTC, Zhongshan Univ., Hong Kong Univ., Chinese Hong Kong Univ., National Taiwan Univ., National Chiao Tung Univ., National United Univ. ~ 150 collaborators The Daya Bay Collaboration Seminář ÚČJF - Vít Vorobel

  21. ? reactor, accelerator atmospheric, accelerator SNO, solar SK, KamLAND 0 23 = ~ 45° 13 = ? 12 ~ 32° P(  e) - P(  e) sin(212)sin(223)cos2(13)sin(213)sin ˉ ˉ 13The Last Unknown Neutrino Mixing Angle ? UMNSP Matrix Maki, Nakagawa, Sakata, Pontecorvo • What isefraction of3? • Ue3 is the gateway to CP violationin neutrino • sector: 2345 Seminář ÚČJF - Vít Vorobel

  22. Measuring 13 Using Reactor Anti-neutrinos e disappearance at short baseline(~2 km): unambiguous measurement of 13 Electron anti-neutrino disappearance probability Small oscillation due to q13 < 2 km Large oscillation due to q12 > 50 km Osc. prob. (integrated over En ) vs distance Sin22q13 = 0.1 Dm231 = 2.5 x 10-3 eV2 Sin22q12 = 0.825 Dm221 = 8.2 x 10-5 eV2 Seminář ÚČJF - Vít Vorobel

  23. Far site 1615 m from Ling Ao 1985 m from Daya Overburden: 350 m Mid site 873 m from Ling Ao 1156 m from Daya Overburden: 208 m Daya Bay Near site 363 m from Daya Bay Overburden: 98 m 4 x 20 tons target mass at far site Daya Bay: Powerful reactor close to mountains 900 m Ling Ao Near site ~500 m from Ling Ao Overburden: 112 m Ling Ao-ll NPP (under construction) 22.9 GW in 2011 465 m Construction tunnel 810 m Ling Ao NPP, 22.9 GW Filling hall entrance 295 m Daya Bay NPP, 22.9 GW Total length: ~3100 m Seminář ÚČJF - Vít Vorobel

  24. Detection of e Inverse -decay in Gd-doped liquid scintillator:  + p  D + (2.2 MeV) (t~180μs) 0.3b • + Gd  Gd* Gd + ’s(8 MeV) (t~30μs) 50,000b Time, space and energy-tagged signal  suppress background events. E Te+ + Tn + (mn - mp) + m e+  Te+ + 1.8 MeV Seminář ÚČJF - Vít Vorobel

  25. Antineutrino Detector 12.2% 13cm • Cylindrical 3-ZoneStructure separated by acrylic vessels: • I. Target:0.1% Gd-loaded liquid scintillator, diameter=height= 3.1 m, 20 ton • II. g-catcher: liquid scintillator, 42.5 cm thick • III. Buffer shielding: mineral oil, 48.8 cm thick With 192 PMT’s on circumference and reflective reflectors on top and bottom: Seminář ÚČJF - Vít Vorobel

  26. Inverse-beta Signals Antineutrino Interaction Rate (events/day per 20 ton module) Daya Bay near site 840 Ling Ao near site 740 Far site 90 Ee+(“prompt”) [1,8] MeV En-cap (“delayed”)  [6,10] MeV tdelayed-tprompt [0.3,200] s Prompt Energy Signal Delayed Energy Signal 1 MeV 8 MeV 6 MeV 10 MeV MC statistics corresponds to a data taking with a single module at far site in 3 years. Seminář ÚČJF - Vít Vorobel

  27. Muon “Veto” System Resistive plate chamber (RPC) • Surround detectors with at least 2.5m of water, which shields the external radioactivity and cosmogenic background • Water shield is divided into two optically separated regions (with reflective divider, 8” PMTs mounted at the zone boundaries), which serves as two active and independent muon tagger • Augmented with a top muon tracker: RPCs • Combined efficiency of tracker > 99.5% with error measured to better than 0.25% Outer water shield Inner water shield Seminář ÚČJF - Vít Vorobel

  28. Backgrounds Background = “prompt”+”delayed” signals that fake inverse-beta events Three main contributors, all can be measured: Background/Signal: Seminář ÚČJF - Vít Vorobel

  29. sin2213 sin2213 (90% C.L.) Goal: 0.01 Run Time (Years) • Ground BreakingOct 07 • CD-3review comletedSpring 08 • Surface Assembly Building occupancyMarch 09 • Mini Dry Run Dec 09 • Dry Run Spring 09 • Daya Bay Near Hall ready for data taking 2010 • All near and far halls ready for data taking 2011 Daya Bay: Status and Plan Seminář ÚČJF - Vít Vorobel

  30. Testování RPC kosmickým zářením – IHEP Peking Kritéria testů: účinnost >95% singles (šum)< 0.8Hz/cm2 dark current< 10 μA/m2 Testováno 1600 ks RPC, odmítnuto 15% Seminář ÚČJF - Vít Vorobel

  31. 谢谢你们 ！Děkuji za pozornost ! Seminář ÚČJF - Vít Vorobel

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