Neutrinoastrophysik bei niedrigen Energien BOREXINO and LAGUNA Astroteilchenphysik in Deutschland, February 2010 Zeuthen DESY Lothar Oberauer, TUM, Physik-Department Forschungsbereich Kern- Teilchen- Astrophysik Institut für experimentelle Astroteilchenphysik

Content New results from BOREXINO Prospects for solar neutrino spectroscopy Prospects for low energy neutrino astronomy Status of LAGUNA and LENA

The dominating solar pp - cycle H. Bethe W. Fowler pp - 1 pp -2 pp -3

The sub-dominant solar CNO - cycle …dominates in stars with more mass as our sun… =>Large astrophysical relevance Measurement of CNO neutrinos = determination of inner solar metallicity

Solar Neutrinos Neutrino Energy in MeV Scintillator BOREXINO Water Cherenkov L. Oberauer, TUM

BOREXINO Neutrino electron scattering n e -> n e Liquid scintillator technology (~300t): Low energy threshold (~60 keV) Good energy resolution (~ 5% @ 1 MeV) very low background Sensitivity on sub-MeV neutrinos Online since May 16th, 2007 L. Oberauer, TUM

Neutrino elastic scattering off electrons Cross section for ne is larger (factor ~5) as for nm,t Expected rate without neutrino mixing ~ 74 counts per day and 100t target Expected rate with neutrino mixing (MSW-LMA) ~ 48 c/(d 100 t) L. Oberauer, TUM

BOREXINO in the Italian Gran Sasso Underground Laboratory in the mountains of Abruzzo, Italy, ~120 km from Rome Laboratori Nazionali del Gran Sasso LNGS Shielding ~3500 m.w.e External Labs Borexino Detector and Plants

BOREXINO Detector layout Stainless Steel Sphere: 2212 PMTs + concentrators 1350 m3 Scintillator: 270 t PC+PPO in a 150 mm thick nylon vessel Water Tank: g and n shield m water Č detector 208 PMTs in water 2100 m3 Nylon vessels: Inner: 4.25 m Outer: 5.50 m Excellent shielding of external background Increasing purity from outside to the central region Carbon steel plates L. Oberauer, TUM

Results on solar 7Be neutrinos Counting rate on solar 7Be-neutrinos: 49 ± 3stat ± 4sys /(d 100t) L. Oberauer, TUM

Results on solar 8B - neutrinos No neutrino mixing neutrino mixing plus (MSW) effect New data for solar 8B neutrinos L. Oberauer, TUM

Systematic uncertainties Calibration with radioactive sources (completed in 2009) Study of response function (e.g. gamma quenching, kb – parameter…) Final systematic uncertainty on 7Be neutrino flux ~ 5% L. Oberauer, TUM

Implications of solar 7Be neutrino result Borexino exp. result: 49 ± 3stat ± 4sys / (d 100t) Solar model (high metallicity, neutrino mixing, MSW): 48 ± 4 / (d 100t) Solar model (low metallicity, neutrino mixing, MSW): 44 ± 4 / (d 100t) Solar model, but no neutrino mixing: 74 ± 4 / (d 100t) Clear confirmation of neutrino mixing and MSW L. Oberauer, TUM

Implications of solar 7Be-neutrino result f = measured / expected (solar model, MSW) Before Borexino fBe = After Borexino fBe = New constraints on pp- and CNO-fluxes from BOREXINO and all other solar neutrino experiments => L. Oberauer, TUM

CNO contribution to solar energy generation Without solar luminosity constraint With solar luminosity constraint CNO contribution to solar energy generation < 5.4 % (90 % cl) L. Oberauer, TUM

Correlation between constraints on pp- and CNO- fluxes Borexino result and solar luminosity constraint fCNO < 4.8 (90 %cl) L. Oberauer, TUM

Survival probability at Earth for solar ne as function of their energy Measurements and expectations (MSW effect) Borexino L. Oberauer, TUM

Prospects of BOREXINO Improvement of systematical uncertainties 7Be flux measurement at < 5 % total uncertainty 8B flux measurement with increased statistics Measurement of pep and CNO-neutrinos (if 11C event rejection and purity allows…) ne measurement by ne p -> e+ n => Geo neutrinos & reactor neutrinos Supernova neutrinos (~100 events) for a galactic SN type II , limits on magnetic moment… L. Oberauer, TUM

New Analysis of SNO phases I and II Threshold at 3.5 MeV (nucl-ex:09102984) L. Oberauer, TUM

Two flavor neutrino oscillation hypothesis analysis Global fit including: Solar neutrino experimental results (SNO, Cl, Gallex/GNO, Sage, Borexino, SK I & II) KamLAND reactor neutrino data (SNO collaboration: nucl-ex:09102984) L. Oberauer, TUM

Three flavor neutrino oscillation analysis nucl-ex:09102984 L. Oberauer, TUM

Three flavor neutrino oscillation analysis Current best parameter values from solar neutrino experiments and KamLAND Q12 = (34.06 + 1.16 – 0.84) degrees Dm212 = (7.59 + 0.20 – 0.21) x 10-5 eV2 Three flavor neutrino oscillation analysis sin2Q13 = (2.00 + 2.09 - 1.63) x 10-2 Limit on Q13: sin2Q13 < 0.057 (95% cl) nucl-ex:09102984 L. Oberauer, TUM

Prospects of low energy neutrino astronomy in Europe 3 large detector types are proposed 0.4 Mt Water Cherenkov (Memphis) 100 kt Liquid Argon (Glacier) 50 kt Liquid Scintillator (LENA) LAGUNA (Large Apparatus for Grand Unification and Neutrino Astrophysics): European funded FP7 design study for a future underground facility in Europe (report to be completed in 2010) L. Oberauer, TUM

LAGUNA Consortium - Italy

Low Energy Neutrino Astronomy – LENA L. Oberauer1, F. v. Feilitzsch1, M. Göger-Neff1, Y. Bezrukov10, A. Sherpukov9, C. Hagner2, J. Jochum3, T. Lachenmaier1,4, T. Lewke1, M. Lindner5, E. Kokko12, K. Loo12, J. Maalampi12 ,T. Marrodán Undagoitia7, G. Nujiten11,Q. Meindl1, R. Möllenberg1, J. Peltoniemi1,4, W. Potzel1, T. Risikko12, K. Rummukainen13, A. Stahl8, M. Tippmann1, C. Traunsteiner1, W. Trzaska6, J. Winter1, M. Wurm1 1 Technische Universität München, Physikdepartment E15, James-Franck-Str. 1, 85748 Garching 2 Universität Hamburg, Institut für Experimentalphysik, Luruper Chaussee 149, 22761 Hamburg 3 Universität Tübingen, Physikalisches Institut, Auf der Morgenstelle 14, 72067 Tübingen 4 The Cluster of Excellence for Fundamental Physics, „Origin and Structure of the Universe“, Boltzmannstr. 2, 85748 Garching (Germany) 5 Max-Planck-Institut für Kernphysik, Am Saupferchweg 1, 69117 Heidelberg (Germany) 6 University of Jyväskylä, Department of Physics, P.O. Box 35 (YFL), FI-40014 Jyväskylä (Finland) 7 Universität Zürich, Physik-Insitut, Winterthurstr. 189, 8057 Zürich (Switzerland) 8 RWTH Aachen, III. Physikalisches Institut, Physikzentrum, 52056 Aachen (Germany) 9Moscow State University (Russia) 10Institute for Nuclear Research, Moscow, Russia 11Rockplan, Helsinki (Finland) 12University Oulu, Oulu (Finland) 13University of Helsinki (Finland) + collaboration with APC, CNRS, Paris (France) for common development MEMPHIS/LENA

LENA Physics Goals Proton Decay Diffuse Supernova Neutrino Background Galactic Supernova Burst Long baseline neutrino oscillations Solar Neutrinos Geo neutrinos Reactor neutrinos Atmospheric neutrinos Dark Matter indirect search L. Oberauer, TUM

~ 50 kt Liquid Scintillator L. Oberauer, TUM

LENA and proton decay High sensitivity to p -> K n (eff. ~ 68% instead 6% in SK t ~ 5 x 1034 y) Sensitive to a variety of decay channels “invisible” modes, e.g. n -> n n n For e.g. p -> e+ p0 we expect ~ 1033 y (work in progress) T. Marrodan et al., Phys. Rev. D72, 075014 (2005) L. Oberauer, TUM

LENA and the Diffuse Supernova Background Excellent background rejection (nep->e+n) Energy window 10 to 30 MeV. High efficiency (100% with 50 kt target) High discovery potential in LENA ~2 to 20 events per year are expected (model dependent) M. Wurm et al., Phys.Rev.D 75 (2007) 023007 L. Oberauer, TUM

LENA and a Galactic Supernova Burst Antielectron n spectrum with high precision Electron n flux with ~ 10 % precision Total flux via neutral current reactions Separation of SN models Spectroscopy of all n flavors Time evolution of neutrino burst Details of SN gravitational collapse Chance to separate low/high Q13 and mass hierarchy (normal/inverted) Coincidence with gravitational wave detectors L. Oberauer, TUM

LENA and long baseline neutrino oscillations Separation between e- and m-like events Pulse shape discrimination (risetime, width) Track reconstruction Muon decay m -> e n n Work in progress electrons (1.2 GeV) muons (1.2 GeV) L. Oberauer, TUM

Study CERN – LENA at Pyhäsalmi (Finland) CERN - Pyhäsalmi 2288 km 5 years nu + 5 years anti-nu 1. Maximum @ 4.2 GeV Wide band beam 1 – 6 GeV 1.5 MW power Sensitivity on theta_13, CP-parameter, mass hierarchy J. Peltoniemi, Simulations of neutrino oscillations for a wide band beam from CERN to LENA, arXiv:0911.4876v1 [hep-ex] L. Oberauer, TUM

CP – violating parameter Detection signifigance (chi) CP – violating parameter preliminary > 3 sigma Log (osc. Amplitude) L. Oberauer, TUM

preliminary L. Oberauer, TUM

LENA and Solar Neutrinos High statistics in 7-Be (~ 5400 events per day) Search for small time fluctuations CNO and pep n (~ 360 events per day) Very sensitive test of MSW effect CC and NC measurements of 8-B Search for spectrum deformation Search for non-standard n interactions Search for solar ne -> ne transitions L. Oberauer, TUM

LENA and Geo-neutrinos LENA is the only detector within Laguna able to determine the geo neutrino flux In LENA we expect between 300 to 3000 events per year (“best bet” ~ 1500 / year) Good signal / background ratio most significant contribution can be subtracted statistically Separation of geological models L. Oberauer, TUM

LENA and Reactor neutrinos At Frejus ~ 17,000 events per year High precision on solar oscillation parameter: Dm212 ~ 1% Q12 ~ 10% S.T. Petcov, T. Schwetz, Phys. Lett. B 642, (2006), 487 J. Kopp et al., JHEP 01 (2007), 053 L. Oberauer, TUM

Pre-feasibility study for LENA at Pyhäsalmi (TUM and company Rockplan, Finland) Depth at 1400 m – 1500 m possible ! Geological study completed Vertical detector position Logistics (Vent, Electricity, etc.) considered Construction time of cavern ~ 4 years 1st costs estimate for the whole project Tank construction plan (accomplished April 2010) L. Oberauer, TUM

favoured option: + Tank Construction: 8 years L. Oberauer, TUM

Conclusions Solar neutrino experiments very successful Strong impact on neutrino oscillation parameter Precise determination of solar nuclear fusion processes Missing CNO-neutrinos -> determination of solar inner metallicity Geo neutrinos (stay tuned !) Prospects (Large detectors like LENA) in this field & proton decay and long baseline experiments LAGUNA design study accomplished in 2010 L. Oberauer, TUM