1. Insights in stars, neutrino physics and in the Earth Gemma Testera INFN Genoa (Italy) “Neutrino Physics: Present and Future” Erice 2013 G. Testera INFN Genoa (Italy) Erice 2013

2. G. Testera INFN Genoa (Italy) 35th Erice School, 2013 The Sun and the H burning stars produce neutrinos 4 He+ 2 e + + 2 e + 26.8 MeV Mean energy =0.53 MeV 2% of the total energy produced Two reaction cycles: pp chain CNO chain Neutrinos from the Sun

3. The pp fusion chain G. Testera INFN Genoa (Italy) 35th Erice School, 2013

4. 12 C + p  13 N +  13 N  13 C + e + + e 13 C + p  14 N +  14 N + p  15 O +  15 O  15 N + e + + e 15 N + p  12 C + 4 He B N O 12 C : catalyst Main CNO cycle The CNO chain Very important for stars with mass higher than the SUN G. Testera INFN Genoa (Italy) 35th Erice School, 2013

5. Solar Neutrino energy spectrum at Earth A. Serenelli et al., Astroph. J. 7432 2011 CNO Neutrinos/cm 2 /sec/MeV G. Testera INFN Genoa (Italy) 35th Erice School, 2013

6. Why do we measure solar neutrinos ? Solar studies began to prove that Sun shines by nuclear fusion reaction: solar are a powerful probe allowing to understand the interior of the Sun The Sun can be used to calibrate stellar models The flux and specrum of allows to discriminate between solar models The Sun is a source of pure  e : good to study oscillations The baseline of 10 8 Km allows sensitivities to  m 2 up to 10 -10 eV 2 The Sun allows probing propagation in a high density medium 100g/cm3: interaction of neutrinos with matter influences the oscillation physics Non standard interactions can produce a measurable signal with solar Mixture of neutrino physics and astrophysics

7. Standard solar model Stars are formed by a gravitationally bound system of primordial gas (roughly Helium 25%, the rest is Hydrogen) Energy loss by radiation contraction heating hydrogen fusion Expansion and balance between gravity and pressure force: hydrostatic equilibirum Sun is in hydrostatic equilibrium Sun is spherically symmetric The energy transport is induced by photons or convection. The radiative energy transport is dominant in the solar core, while the convective energy transport becomes important near the solar surface Energy production is due to nuclear reactions Initial parameters X ini : initial mass fraction of Hydrogen Y ini : initial mass fraction of Helium Z ini : initial mass fraction of all others elements (called metals) Characteristic lenght scale for convection Others parameters: cross sections of nuclear reactions Solar model hypothesis

8. Evolution up to the solar age : 4.57 Gy The model must reproduce -The measured Sun luminosity L -The Sun radius R -The ratio Z/X (metal/Hydrogen) at the Sun surface (surface metallicity) The input parameters are changed until the present day data are reproduced Output of the solar model production region and fluxes and spectra Depth of the convection zone R CZ Surface Helium abundance Y surf Profile of X(r),Y(r), Z(r), Density and sound speed profile vs r Standard solar model

9. How to measure the Z/X value ? - Chemical analysis of primitive meteorites - emission line from solar corona - composition of the solar wind New method (recently developed): development of three-dimensional radiation hydrodynamic (3D RHD) models of the solar athmosphere : revision of the solar composition determined from the solar spectrum. Z/X from the 3D RHD model = 0.0178 Previous value of Z/X = 0.0245-0.0249 Two flavours of Standard solar model 1)High metallicity (old Z/X) : older model, it does not match the Z/X measured with the new 3D RHD model 1)Low metallicity (new Z/X) : it reproduces the new measured value of metallicity; but this does not match the elioseismic data High and low metallicity

10. Helioseismology: acustic oscillations of the Sun surface The study of the Sun internal structure entered a new age with helioseismoogy (about 20 years ago, before the formulation of the new models of the Sun athmosphere) Millions of solar modes (frequencies) have been detected From the measured frequencies you get : - sound velocity in the Sun’s interior; - constraints about radiative opacity; - constraints about chemical composition; elioseismology solar interior High metallicity solar models reproduce the elioseismology data Low metallicity models do not reproduce elioseismology data Low metallicity models reproduce the modern measurements about surface metallicity Reproduction of elioseismology: success of the Standard Solar model before evidence of neutrino oscillations. High and low metallicity and elioseismology

11. Solar Neutrinos flux predictions Aldo M. Serenelli et al. 2011 ApJ 743 24 Present predictions CNO High metallicity Low metallicity G. Testera INFN Genoa (Italy) Erice 2013 Diff. % pp0.8 pep2.1 7 Be8.8 8B8B17.7 13 N26.7 15 O30.0 17 F38.4 Present predictions: High and Low metallicity

12. The solar neutrino problem and its solution expyearsreactionthresholdSolar sensitivitymethodresult Chlorine1968 - 1994 e + 37 Cl= e- + 37 Ar 0.814 MeV8B, pep, 7Beradiochemical 615 tons R(exp/SSM)=0.34±0.03 Gallex-GN01991-2003 e + 71 Ga= e - + 71 Ge 0.2338B, pep, 7Be,ppRadiochemical 30.3 t R(exp/SSM)= 0.58±0.05 SAGE1990- e + 71 Ga= e - + 71 Ge 0.2338B, pep, 7Be,ppradiochemical 50 t 0.59±0.06 Kamiokande (SuperKamiokande still running) 1987-1995 x +e-= x +e- 7.5 … 3.5 8BCerenkov light 2.14 Kt water (22.4 Kt) 0.46±0.02 SNO1999 2006 (moving to SNO+) e +d=e - +p+p (CC) e +d= x +p+n (NC) e +e - = x +e- (ES) 5 3.5 8B1Kt D 2 0 Cerenkov 8B flux consistent with SSM!! Solar neutrino problem solved Kamland (reactor antinu) 2002 - Anti  e +p= n+e- Liquid scintillatorReactor antinu L/E sensitive to solar region Borexino2007- x +e-= x +e- 0.28B, pep, 7Be,ppLiquid scintillator7Be,pp,8B G. Testera INFN Genoa (Italy) Erice 2013

13. Now we know that oscillate: move the focus to low energy solar spectroscopy Evidence of oscillations and massive neutrinos Interaction of neutrinos with matter complicate the oscillation scenario Important for solar (and supernova) neutrinos: MSW Year 2002: SNO results with NC Nobel Prize for R. Davis (chlorine exp.) and Koshiba Kamland results Solar mainly influenced by Solar neutrino measurements now: understand details of the oscillation model provide input for solar models Borexino : very low energy solar spectroscopy 2 flavours: Kamland +solar PRL 94 081801 (2005) LMA-MSW arxiv 1303.4667v1 (2013) Kamland Coll. G. Testera INFN Genoa (Italy) Erice 2013

14. Water Tank:  and n shield  water Č detector 208 PMTs in water Scintillator: 270 t PC+PPO (1.5 g/l) in a 150  m thick inner nylon vessel (R = 4.25 m) Stainless Steel Sphere: R = 6.75 m 2212 PMTs Outer nylon vessel: R = 5.50 m ( 222 Rn barrier) Buffer region: PC+DMP quencher 4.25 m < R < 6.75 m The smallest radioactive background in the world: 9-10 orders of magnitude smaller than the every-day environment  ≈500 phe/MeV (electron equivalent)  Energy resolution 4.5%  Space resolution 10 cm @1MeV  “wall less” Fiducial Volume  Pulse shape capability  Calibration in situ with radioactive sources  Accurate Monte Carlo modeling of the energy and time response function No signature except the spectral shape Needed extremely low background detection: elastic scattering on electrons The lowest energy threshold in a real time detector solar detector: Borexino @G. Sasso Laboratory (Italy) G. Testera INFN Genoa (Italy) Erice 2013

15. 7 Be (0.862 MeV) solar flux from Borexino G. Bellini et al., Borexino Collaboration, Phys. Rev. Lett. 107 (2011) 141362.  e flux reduction 0.62 +- 0.05  e survival probability 0.51 +- 0.07 @0.862MeV G. Bellini et al., Borexino Collaboration +C Pena Garay, Phys. Lett. B707 (2012) 22. G. Testera INFN Genoa (Italy) Erice 2013

16. pep (1.44 MeV) solar flux measurement and CNO limits in Borexino G. Bellini et al., Borexino Coll., Phys. Rev. Lett. 108 (2012) 051302 Interaction Rate (cpd/100t) DATA/SSM (high metallicity) Counts/(days 100 t)ratio pep3.1±0.6 (stat) ± 0.3(sys)1.1±0.2 CNO<7.9<1.5 Best limit on CNO- not yet enough to select solar models…. G. Testera INFN Genoa (Italy) Erice 2013 pep CNO

17. Can we discrimininate between solar models ?? High met. (1  ) Low met. (1  ) G. Testera INFN Genoa (Italy) Erice 2013 Borexino data

18. Figure from PRC 84, 035804 (2011) Kamland coll. SNO has provided the absolute 8B flux 8 B solar neutrinos G. Testera INFN Genoa (Italy) Lepton Photon 2013

19. Kamland PRC 84, 035804 (2011) Borexino (3MeV threshold) arxiv 1109.0763 SNO LETA 3.5 MeV threshold Super K. Suzuki@Neutrino Telescopes Venice 2013 8 B solar neutrinos LMA prediction G. Bellini et al. PRD 82 033006 (2010) SNO CC events SuperKamiokande G. Testera INFN Genoa (Italy) Erice 2013

20. Solar 8 B : the Up-turn??? LMA survival probability lower the thereshold as much as possible Hints for new physics?? Background issues Statistics SuperKamiokande can see the effect arxiv 1012.5627v2 (2011) G. Testera INFN Genoa (Italy) Erice 2013

21. Assuming the luminosity constraint G. Testera INFN Genoa (Italy) Erice 2013

22. Electron neutrinos survival probablity P ee Combined analysis Borexino&solar Pee as expected from oscillation +Matter effect (LMA-MSW) Vacuum regime Matter regime G. Testera INFN Genoa (Italy) Erice 2013 LMA prediction

23. arxiv 1305.5835v1 (2103) P ee and not standard interactions

24. Direct measurement of pp neutrino spectrum: test Sun luminosity High precision pep: Non Standard Interactions (NSI), test LMA with accuracy Measure CNO : solar and stellar models 8 B up-turn: reduce the threshold (non standard interactions, sterile neutrinos…) Improve 7 Be measurement (and calculation) (solar models) What next on solar neutrinos??? What next ? Borexino Phase II After the purification of the scintillator 1)Krypton: strongly reduced: consistent with zero cpd/100t from spectral fit 2) 210 Bi : from ~70 cpd/100tons to 20 cpd/100tons) ; 3) 238 U (from 214 Bi-Po tagging) < 9.7 10 ‐19 g/g at 95% C.L. 4) 232 Th < 2.9 10 -18 g/g at 95% C.L. 5) 210 Po 6)It may be possible to estimate the 210 Bi content from 210 Po evolution in time; 7)pp, higher precision pep and 7Be, toward CNO: are in the wish list of Borexino G. Testera INFN Genoa (Italy) Erice 2013

25. What next ? SNO+ Fill SNO with liquid scintillator 780 tonnes LAB+PPO 9000 PMTS Water shield by Ultra Pure Water Wide physics program Assuming the Borexino background level Begin scintillator filling: early 2014 Check Background Priority is  decay (add 130 Te to scintillator) Reduced 11 C background due to the depth 10 4  /day@Borexino 70  /day@SNO+ …..The worse enemy is 210 Bi G. Testera INFN Genoa (Italy) Erice 2013

26. What next : LENS Indium based liquid scintillator R. Raghavan, Phys.. Rev. Lett. 37, 259 (1976) prompt Delayed  =4.6  s Q= 114 keV sensitivity to pp, 7 Be, pep, CNO, 8B Clean spectral measurement: E =e - -114keV SignalBackground Random coincidences of  decay of 115 In (In activity ≈0.25 Bq/g) Important only for pp 10 t In: 400 pp/year 8 1013 decays/year 3D segmentation of the detector: Lattice with teflon reflectors, PMTS at the end Space and time cuts Clean signature of e events (In pure LS the spectral shape is the only signature) G. Testera INFN Genoa (Italy) Erice 2013

27. C. Grieb et al.,PhysRevD 75 0903006 (2007) Simulated spectrum; 5 years, 10 tons of Indium loading in LS What next ? LENS Indium based liquid scintillator 8% In can be loaded in LS 9000 g/MeV (about 75 % of clean LS) Att. Lengh 8m Time stability > year Detector prototype under test in the Kimbalton mine (Virginia): 6X6X6 lattice 130 liters LS (microLens) LENS expected performances G. Testera INFN Genoa (Italy) Erice 2013

28. What next:? Cryogenic Xenon, Neon (noble liquid) scintillators for low en. solar spectroscopy K. Hiraide Moriond 2013 First run performed Detector upgrading Resuming data taking in summer 2013 Current focus: Dark matter Long term goal: solar neutrinos CLEAN conceptual design 100t liquid neon Astroparticle Physics 22 (2005) 355 M. Kinsey et al., Small prototype running at SNOLAB arxiv 1111:3260v2 (2012) arxiv 1301.2815v1 (2013) G. Testera INFN Genoa (Italy) Erice 2013

29. What next: LENA Liquid scintillator and PMT: scaling up (X 150) Borexino keeping its performances (or doing even better) G. Testera INFN Genoa (Italy) Erice 2013

30. SUPERNOVA neutrinos About 20 events from SN1987A detected by KamiokandeII, IMB (water Cerenkov)+ Baksan, LSD (scintillators) Supernova rate: few/100 years Not negligible probability now Present and planned neutrino detectors may see order of magnitude more events that for SN1987A Many models Stellar physics MSW Neutrino-neutrino interactions – collective flavour oscillations Special signature in the emitted neutrino spectra Complicated link between shape of the original flux and oscillations Signature in the shape of the spectra reaching the detectors Light curves: time evolution of the detected neutrino signals Earth matter effect Effect sensitive to the mass hierarchy S. Choubey et al. arXiv:1008.0308 (2010) with many refences Dighe, Smirov arXiv: 9907423v2 (1999) G. Testera INFN Genoa (Italy) Erice 2013 Be ready to measure all the flavours, time and energy spectra!

31. Prompt e burst AccretionCooling Fisher et al.,2010 [arxiv:0908.1871] SUPERNOVA neutrinos: example of time evolution of n luminosity G. Testera INFN Genoa (Italy) Erice 2013

32. Adapted from H. Duan, JJ Cherry “Aspen Winter Workshop” Feb 2013 SUPERNOVA neutrinos: several differences in models G. Testera INFN Genoa (Italy) Erice 2013

33. 1.8 MeV threshold, high cross section Clean signature if n can be detected (Liquid scint., Gd in water at Superk) Largest cross section En> 1.8 MeV All flavour, directionality, no energy threshold Inverse beta decay Elastic scatt. CC reactions on nuclei E threshold, signature (daughter in excited states ) p elastic scattering Low recoil energy Ok for scintillators (many free protons) Sensitive to x SUPERNOVA neutrinos: several channels in present and future detectors Nucleus elastic scattering G. Testera INFN Genoa (Italy) Erice 2013 Low recoil energy Possible in cryogenic noble liquid scintillators “prompt signal” e+: energy loss + annihilation (2  511 KeV each) “delayed signal” n capture after thermalization (2.2  in 

34. K. Scholberg arxiv 1205.6003v1 (2012) SUPERNOVA neutrinos: expected number of events Take this as example: many variations from model to model SuperK: mainly Addition of Gd in water: project well advanced!! G. Testera INFN Genoa (Italy) Erice 2013

35. SUPERNOVA neutrinos:  p elastic scattering in low background liquid scintillators B. Dasgupta, J. Beacom arxiv 1103.2768 (2011) J. Beacom et al., arxiv 0205220 (2002) Superkamiokande will mainly measure anti- e e : the best detector is probably liquid argon  p scattering important for measuring the spectrum of   and antinu (all x ) =8 MeV =5 MeV =3.5 MeV True proton recoil spectrum Sensitive to ! 200 KeV energy threshold Expected recoil spectrum including quenching ( SNO+ taken as example) 111 events @ SNO+ 27@ Borexino 66@ Kamland >10 3 @LENA Low backgroun technologies developed for solar make detectors powerful for Supernova …. G. Testera INFN Genoa (Italy) Erice 2013

36. Atmospheric anti- e reactor solar RELIC supernova neutrinos G. Testera INFN Genoa (Italy) Erice 2013

37. RELIC supernova neutrinos:upper limits from SupeKamiokande (2012) Event rate from DSNB in 22.5 Kt water Cerenkov detector (SuperKamiokande) Experimental program to add Gadolium in water is in progress; Interesting perspectives for the DSNB detection in SK

38. Antineutrinos from the Earth: geo The crust and upper mantle are reasonably known What about the lower mantle and the core? Geo allows to see the inner part of the Earth If enough data will be collected then it will be possible to discriminate between Earth’s model Anti v emiited by U,Th,K: related to the radiogenic heat G. Testera INFN Genoa (Italy) Erice 2013 CMB: Core Mantle Boundary

39. Energy spectrum of geo :  Low flux: 3 order of magnitude less than 7 Be solar !  Geo : they probe the U,Th content of the Earth (no K)  Multidisciplinary research: particle physics&geophysics  Possible because low back detectors have been developed for solar and reactor neutrinos E >1.8 MeV Antineutrinos from the Earth: geo Detected by Kamland and Borexino G. Bellini et al., (Borexino Coll.) Phys. Lett. B 687 (2010) 299; Phys Lett B 722 4 (2013) 295 Borexino Coll. T. Araki et al., (Kamland Coll.) Nature 436 (2005) 499; A. Gando et al. (Kamland Coll.) Nature Geoscience 4 (2011) 57 ; arxiv 1303.4667v1 (2013) Kamland Coll. See Neutrino Geoscience (Takayama) 2013 G. Testera INFN Genoa (Italy) Erice 2013 10 6 cm –2 s –1 from U and Th in the Earth 10 7 cm –2 s –1 from potassium, Compare with flux of 6 × 10 10 cm –2 s –1 from the Sun

40. The temperature of the Earth increases with the depth : about 25° C/Km Internal heat = residual heat from formation of the planet (about 20%) + contribution from radioactive decays of long life isotopes (U, Th, K) T(core) = 6000-7000 K! Below 80 -100 Km from the surface: melted rocks Heat flows toward the surface Heat loss from the Earth = 47 TW (4.7 × 10 13 Watts) (or 30 TW?) The present day heat source is by radioactive decays Measuring the geov : determine the amount of U and Th and thus constrain the radiogenic heat From meteorites: U:Th = 3:9 The generation of the Earth’s magnetic field, its mantle circulation, plate tectonics and secular (i.e. long lasting) cooling are processes that depend on terrestrial heat production and distribution Heat balance G. Testera INFN Genoa (Italy) Erice 2013

41. 1MeV≈ 500 p.e. Simulation for Borexino Simulation for Kamland Reactors anti are a source of background Lower effect in Borexino ( there are not near reactors) Borexino has also lower background (accidental,  n…) But larger target mass in Kamland 300t/1000t before the FV cuts Detection of geo  and the reactor background reactors Geo G. Testera INFN Genoa (Italy) Erice 2013

42. geo results in 2103 G. Testera INFN Genoa (Italy) Erice 2013

43. Chondritic U-Th ratio Best fit S( 238 U) = 26.5 ± 19.5 TNU S( 232 Th) = 10.6 ± 12.7 TNU Try to find the contribuion of U and Th Kamland Borexino Best fit S( 238 U)= 116 events S( 232 Th) = 8 events G. Testera INFN Genoa (Italy) Lepton Photon 2013

44. Geo : implications about Earth models G. Testera INFN Genoa (Italy) Erice 2013 TNU=1ev/ (y 10 32 protons)

45. Conclusions Solar neutrinos entered in the spectroscopy phase Interest for solar models (CNO) Verification of the oscillation physics (pep for Pee and NSI, Upturn of 8B) Direct pp measurement expected Geoneutrinos have been detected : more data are neceessary to constrain Earth models Low background detectors developed for solar physisc have great potential for Supernova Understanding details of supernova physics demands next generation detectors (high statistics) Supernova neutrinos are very rich of informations about astrophysics and neutrino properties G. Testera INFN Genoa (Italy) Erice 2013