Non-oscillation Neutrino Physics

1. Non-oscillation Neutrino Physics Y. Ramachers

2. Outline • Physics in non-oscillating neutrino experiments • Neutrino Physics in Beta-Decays • Single Beta Decay • Double Beta Decay • Exploiting existing neutrino populations • Summary for discussion Y. Ramachers

3. Physics topics in non-oscillating neutrino physics • Theory of Flavour • Neutrino mass, Majorana or Dirac nature • Mass mechanism = physics at high energy scales • Exotic interactions = Beyond SM interactions • (Scalar and tensor contributions to V-A from any BSM theory, Lepton number violation → Leptogenesis) • Exploiting existing neutrino populations • (e.g. primordial-, geological-, solar-, atmospheric-, supernova-, reactor neutrinos) Y. Ramachers

4. Neutrino Physics in Beta Decays Single Beta Decay: Double Beta Decay: Y. Ramachers

5. Single and Double Beta Decay – fundamentally different playing fields Y. Ramachers

6. Single Beta Decay Two complementary experimental approaches Charge Spectrometer: KATRIN Calorimeter: MARE • Source: Tritium, Q-value 18.6 keV • Filter electron energies: • magnetic field lines guide electrons, • electrostatic field filters energies • Count electron events above filter threshold • Energy resolution target: 0.93 eV • Mature technology: Mainz/Troitsk limit achieved 2.2 eV • Sensitivity target: 0.2 eV • http://www-ik.fzk.de/~katrin/index.html • Source: Rhenium-187, Q-value 2.5keV • Source = Detector: Cryogenic micro-calorimeter • Energy resolution: 10-20 eV • Mature technology: TES thermometry on rhenium microgram crystals • Sensitivity target: Test Mainz/Troitsk result of 2.2 eV • Long-term: MARE-2, target 0.2 eV • http://mare.dfm.uninsubria.it/ Y. Ramachers

7. Main spectrometer commissioning WGTS construction/ commissioning first sub-eV result! Commission full apparatus T2 endpoint data 2010 2011 2012 2013 2014 2015 2016 2017 KATRIN Schedule and UK interest(from Brent A. VanDevender, CENPA - UWCIPANP09 conference) Detector construction/commissioning UK-interest: KATRIN Webpage lists • Swansea • CCLRC Daresbury • UCL Swansea un-funded but well- established = pivotal role on tritium source spectroscopy. (currently funded by Karlsruhe!) Contribution requirement estimate: £120k per year from 2012 + lump investment of £200k soon Pre-spectrometer commissioning Y. Ramachers

8. K(Ee) Q – M3 Q – M2 Q – M1 K(Ee) Q Ee Ee Single Beta Decay Physics topics covered: • Neutrino mass, direct measurement • Exotic interactions: scalar, tensor contributions to V-A. • Primordial neutrinos inducing inverse beta decay. • Even ν-oscillation physics! Assessment: • Well established, un-funded UK-contribution, notably by Swansea. • Approved next-generation experiments well underway. • All supposed ‘science fiction’ hinges on revolutionary energy resolution or plainly NEW ideas, i.e. genuine Blue-Sky research! A. Giuliani, PIC’05 Cosmic neutrino background detection, see M. Blennow and ref. therein, astro-ph/0803.3762 Y. Ramachers

9. Double Beta Decay Source  detector (foil+tracking+calorimetry) Two approaches Source = detector (calorimeters) 214Bi 214Bi unknown 0ββ? Isotope flexibility “smoking” gun Topological bkg suppression e.g. Heidelberg-Moscow Great ΔE/E compact e.g. NEMO-III Y. Ramachers

10. New Experiments Y. Ramachers

11. SuperNEMO Design study almost finished On course to achieve all deliverables. UK Proposal for Demonstrator module pending. UK now shares 80% of responsibilities with France Major player not by construction but by work delivered. SNO+ UK Proposal for minimal investment pending. Collaboration partner ‘in kind’, already due to previous SNO investment. Minimal effort for maximum physics return is possible here. NEWS: SNO+ approved by Canadian CFI grant! Its going to happen in Nigel’s SNOLab facility. Experiments with UK interest Y. Ramachers

12. What could this mean for a UK Double Beta Strategy? Time-line 2009 2014 2018 2022+ 2010 2012 SN demonstrator running Construct/ install SN construction SN full running 500 kg yr 250 kg yr collected SNO+ DB Phase I SNO+ DB Phase II R&D and construct Opportunity for an X-ton experiment: R&D, 100kg phase, X-ton phase Investment SuperNEMO: average £1.83M per year for 2009 – end 2012 £10-15M total for end 2012 - 2019 SNO+: average £440K per year until 2015 for Double Beta Y. Ramachers

13. More Double Beta Strategy • Klapdor Evidence is true: • SNO+ phase I provides first confirmation with different isotope • SuperNEMO (potentially) measures physics mechanism AND • provides third (or fourth) isotope for nuclear matrix element calibration. • Klapdor evidence wrong: • Back to discovery search: Does phase II SNO+ work? R&D! • SuperNEMO on equal footing with international competition. • SNO+ phase II discovers peak ? Back to (1) with ‘’SNO+ evidence’’ and SuperNEMO for confirmation and new isotope (like others) AND physics mechanism. • SuperNEMO finds evidence at limit of sensitivity? Need X-ton experiment. • Nothing detected – need X-ton experiment. Time Y. Ramachers

14. Experiments: Example (1) SuperNEMO UK: UCL-HEP, UCL-MSSL, Manchester, Imperial Next-generation tracking detector Planar geometry. 20 modules for 100+ kg Baseline design: Source: 40 mg/cm2; 12 m2 per module Readout per module: ~ 2k geiger channels for tracking ~ 700 PMTs (250 for scintillator bar design) Single sub-module with ~5 kg of isotope Test Klapdor evidence by 2014 R. Saakyan, SLAC Exp. Seminar, Jan. 2008 Y. Ramachers

15. Experiments: Example (2) SNO+ Slides kindly provided by Steve Biller Y. Ramachers

16. SNO+ Replace 1000 tonnes of ultrapure D2O with 800 tonnes of ultrapure scintillator (so, technically, should be “SNO-”) Physics with Liquid Scintillator • pep and CNO low energy solar neutrinos • tests details of neutrino-matter interaction • sensitivity to 13 • solve “Solar Composition Problem” • Low energy 8B solar neutrinos (& possibly 7Be) • Neutrinoless double beta decay • Geo-neutrinos • 240 km baseline reactor neutrino oscillations • Supernova neutrinos Y. Ramachers

17. Liverpool Universityhas also expressed interest in possible future involvement (permanent academics indicated in bold) Current UK SNO+ Involvement Oxford University: Steve Biller, Nick Jelley, Armin Reichold, Phil Jones (UK PI) Sussex University: Elisabeth Falk, Jeff Hartnell, Simon Peeters, Shak Fernandes, Andrew Baxter (Head SNO+ Calibration Group) plus, Nigel Smith (formerly of RAL) has been appointed new director of the larger SNOLAB major underground science facility Leeds University: Stella Bradbury, Joachim Rose Queen Mary University of London: Jeanne Wilson (SNO+ Analysis Coordinator) Y. Ramachers

18. Example: Test <mn> = 0.150 eV Klapdor-Kleingrothaus et al., Phys. Lett. B 586, 198, (2004) Initially will be limited to ~ 0.1% owing to opacity of loaded scintillator One year with 0.1% of natural Nd-loaded liquid scintillator in SNO+ : small but statistically significant distortion Better suppress 208Tl and enhance loading (or enrich) to increase the sensitivity further Y. Ramachers

19. An X-ton device? Other constraints: Background, ΔE, tracking 1 ton enriched Double Beta Material cost? Least amount of compromises results in an: Enriched Xenon TPC (liquid or high pressure gas) Example: The NEXT experiment and UK-interest: Informal (early) contacts established to part of EXO group Y. Ramachers

20. Exploiting Neutrino populations SNO+ Slides kindly provided by Steve Biller Y. Ramachers

21. SNO+ Physics with Liquid Scintillator • pep and CNO low energy solar neutrinos • tests details of neutrino-matter interaction • sensitivity to 13 • solve “Solar Composition Problem” • Low energy 8B solar neutrinos (& possibly 7Be) • Neutrinoless double beta decay • Geo-neutrinos • 240 km baseline reactor neutrino oscillations • Supernova neutrinos Y. Ramachers

22. Financial issues to consider Y. Ramachers

23. Backup slides Y. Ramachers

24. Summary for discussion UK-commitments: These are long-term experiments!! Start this year and expect 5-10+ year commitments. Single Beta Decay: • Little room for participation → all bases covered → encourage NEW ideas → genuine Blue-sky research funding. Double Beta Decay: • Find something exciting AND financially prudent which is front-line science also in 5-10 years time. • Protect existing investments and success → SuperNEMO and SNO+ • UK has become a major player in double beta decay → protect position by preparing the next step now, i.e. life after SuperNEMO. Neutrino-populations: • Get into at least one all-purpose detector → get in early with expertise that does not cost much for maximum return. • Protect existing investments and success → SNO to SNO+ Y. Ramachers

25. pep & CNO Solar Neutrinos • pep n directly tests solar luminosity constraint & probes MSW in sensitive 1.4 MeV regime to test for non-standard interactions: Friedland et al., Phys. Lett. B, 594, (2004) Barger, Huber & Marfatia, hep-ph/0502196 pep Also sensitive to 13 - complementary to long baseline and reactor experiments: (hypothetical 5% stat. 3% syst. 1.5% SSM measurement has discriminating power for q13 ) • CNO n gives information on age of Globular Clusters and also aims to solve “Solar Composition Problem” (contradictions with helioseismology) (Pena-Garay & Serenelli, arXiv:0811.2424) Y. Ramachers

26. Plus, can also make 8B measurement below SNO energy and likely measure 7Be with more statistics than Borexino, providing a truly comprehensive and definitive solar neutrino study! SNO+ pep & CNO Solar Neutrino Signal SNOLAB depth of 6000mwe gives a muon flux 800 times less than KamLAND and virtually eliminates background from 11C, making SNO+ uniquely sensitive for a precision measurement. 3600 pep events/(kton·year), for electron recoils >0.8 MeV Y. Ramachers

27. Double Beta Decay: Double Beta Decay 2nbb Experimental signature Allowed and observed 0nbb Forbidden – Interesting ! Neutrinos must be massive Majorana particles Y. Ramachers

28. Success and further improvements: HowTo’s On the way to 100meV: Missing factor 2-5 gained by • 16-625 fold increase in exposure (Mt) and/or • 16-625 fold reduction of background, B On the way to 10meV : Extrapolate existing experiments over 5-6 orders of magnitude !!! Not at all hopeless, but a challenge ! Y. Ramachers

29. A hypothetical bb-experiment All reviews agree on one point: There is no optimalbb-experiment! So, pick out what is good and compromise for a practical solution: A highly subjective procedure (A) Simple detector technology (best possible energy res. highest efficiency) (C) Lowest possible B • Tracking SuperNEMO, NEXT, MOON • Intrinsic cleanliness GERDA, CUORE, EXO • Active veto shielding GERDA, EXO, SNO+ (B) Best practical bb-isotope (high-Q value, enrichment costs) Y. Ramachers

30. Counts [a.u.] Counts [a.u.] Electron sum energy/Q-value HowTo 2 Energy resolution and Irreducible background (2nbb) Need good DE Need good e Need high enrichment, a Measurement time t limited Background and Mass count most Choose appropriate detector technology (e, DE, a, t, cost for M) and work on B ! Y. Ramachers

31. Techniques Y. Ramachers

32. Table compiled by Ruben Saakyan * Matrix elements from MEDEX’07 or provided by experiments Y. Ramachers

33. SuperNEMO Schedule overview 2014 2009 2010 2011 2012 2013 NEMO-III running Data Analysis Demonstrator construction Installation at LSM Demonstrator running at LSM Full detector construction First super-modules running at New-LSM TDR and full proposal Background result Continuous physics exploitation in parallel with construction Y. Ramachers

34. Last module installed 250 kg yr collected Demonstrator 1st result matching GERDA1 Expected CUORE result Full Detector running GERDA1I result (35 kg) Demonstrator running S-module installation and running S-module installation and running S-module installation and running 500 kg yr S-module installation and running SuperNEMO running 2018 2013 2014 2015 2016 2017 Future 1t project may start in ~2021-2022

35. SuperNEMO NEMO-3 150Nd or 82Se isotope 100Mo isotope massM 100-200 kg 7 kg efficiency  ~ 30 % 8 % 208Tl mBq/kg if 82Se: 214Bi  10 mBq/kg 208Tl: < 20 mBq/kg 214Bi: < 300 mBq/kg internal contaminations 208Tl and 214Bi in the bb foil energy resolution (FWHM) 8% @ 3MeV 4%@ 3 MeV T1/2(bb0n) > 2 x 1024 y <mn> < 0.3 – 0.9 eV T1/2(bb0n) > (1-2) x 1026 y <mn> < 0.04 - 0.11 eV SuperNEMO Y. Ramachers

36. SuperNEMO Design Study (2006/09) • Tracker (UK sole responsibility) • 1, 9, and 90-cell prototypes • Wiring robot • Deliverables: SuperNEMO tracker and wiring robot design • Calorimeter and Calibration (UK strong involvement) • Energy and time resolution • Calibration system design • Deliverables: 7-8% FWHM /√E(MeV), 1% calibration precision. • Calorimeter design (blocks vs bars) • Software and simulations (UK major contribution) • Full chain of GEANT4 based detector modelling, GRID interface • Physics simulations • Deliverables: Physics reach dependence on detector parameters • Low background studies and source production • HPGe and BiPO detectors development • Source production technology • Deliverables: <10 μBq/kg sensitivity of U and Th with BiPo, • ≥ 5kg of 82Se (4kg in hand) Y. Ramachers

37. The NEXT experiment J.J. Gomez-Cadenas, TAUP09 Y. Ramachers

38. J.J. Gomez-Cadenas, TAUP09 Y. Ramachers

39. D. Nygren, CIPANP09 Y. Ramachers

40. D. Nygren, CIPANP09 Y. Ramachers

41. 3 Sigma Statistical Sensitivity in SNO+ If Nd can be enriched or concentration boosted by other means corresponds to 0.1% natural Nd in SNO+ 500 kg isotope 56 kg isotope starts to probe inverted hierarchy 3 sigma detection on at least 5 out of 10 fake data sets 2n/0n decay rates are from Elliott & Vogel, Ann. Rev. Nucl. Part. Sci. 52, 115 (2002) Note: These are statistical sensitivities only... systematics will degrade this to some extent. However, below 100meV & 50meV, respectively, are not unreasonable expectations if backgrounds are controlled. Y. Ramachers

42. Each SNO+ point represents a different MC “experiment” so as to reflect the statistical spread of derived limits. Ultimately, the ability to achieve such sensitivities in practise may rest on securing sufficient control of backgrounds due to unwanted isotopes in the Nd itself through: 1) careful sourcing of the Nd metal; 2) chemical purification techniques; 3) possible use of additional physical barriers (such as a Borexino-style inner “bag”)) 4) development of software techniques to discriminate against backgrounds; 5) further efforts to secure enriched Nd. Y. Ramachers

43. Unique opportunity to have major impact over diverse range of forefront physics & establish foothold in world leading SNOLAB facility for little more than the cost of travel and postdoc support!! Canadian CFI grant recently approved to provide full funding for SNO+, strengthening the major investment in SNOLAB underground facility. US DOE support is also in place. Status: The UK group is still awaiting a decision on the PRD proposal submitted to PPRP last October. The intention remains to submit a full proposal in 2010, given that detector turn-on is expected in 2011. Y. Ramachers