LENA

1. LENA LENA Delta L. Oberauer, F. von Feilitzsch, M. Göger-Neff, T. Marrodan, P. Pfahler, W. Potzel, M. Wurm Technische Universität München www.e15.physik.tu-muenchen.de/research/lena.htlm Low Energy Neutrino Astrophysics

2. LENA 50 kt liquid scintillator detector 100m 30m Muon veto 30% coverage up to ~60% (light cones) • Scintillator solvent: PXE, or PXE/mineral oil mixture • non hazardous, flashpoint 160° C easy handling • density up to 0.99 high self shielding • high light yield low energy events • low background level U, Th solar n, geo n, snr n

3. LENA at CUPP • transport of PXE via railway • loading of detector via direct pipeline • no fundamental security problem with PXE • no fundamental problem for excavation • LENA is feasible in Pyhäsalmi !

4. Scintillator for LENA CTF at Gran Sasso (BOREXINO) Absorption- and Scattering lengths at TU München Coverage 30% ~ 100 pe / MeV for an event at the center up to ~ 200 pe / MeV with light cones should be possible

5. Supernovae Relic ne 3 models (different spectral shapes): Lawrence Livermore – LL Keil, Raffelt, Janka – KRJ Thompson, Burrows, Pinto - TBP Large systematic uncertainties UV (blue), Ha (green) and FIR (red) are impeded by dust extinction

6. Supernovae Relic ne SRN Rate (between 9.5 and 30 MeV): 40 – 77 / (10 a) Background ~ 21 / (10 a) Spectral shape analysis possible Redshift z ~ 2 Separation LL vs. TBP possible (90% cl)

7. Supernovae Relic ne Threshold at Kamioka ~ 12 MeV (for water Cherenkov detectors) Redshift z ~ 1 Between 21% and 37% lower rate (compared to Pyhäsalmi) Best locations: Hawaii, Australia…

8. Supernova Neutrinos Assumption: Supernova II with 8 solar masses at 10 kpc distance ne flux and spectrum ne flux and spectrum

9. Supernova Neutrinos Total neutrino flux Total energy spectrum

10. Supernova and neutrino properties • „Wiggles“ in the ne spectrum observable • if spectra or fluxes of SN neutrino flavors differ • if neutrinos pass the Earth before entering LENA yes no Smirnov, Dighe, Raffelt...

11. Solar Neutrinos LENA Fiducial Volume for solar n: 18 x 103 m3 • High statistic ( ~ 5.4 x 103 / day ) 7Be n + e ->n + e • test of small flux fluctuations in time • CNO and pep – neutrinos ( ~ 3 x 102 / day ) • solar neutrino luminosity • contribution of CNO cycle to solar energy release • Charged current ne (13C,13N) e- reaction ( ~ 103 / year ) • spectroscopy of 8B-n at energies below 5 MeV • (A. Ianni et al., hep-ph/0506171)

12. Test of MSW effect 7Be pep CNO MSW effect 8B 8B via 13C

13. Geo Neutrinos • Detection via inverse beta decay • measurement of radiogenic contribution to terrestrial heat (~ 40 TW) • test of the Bulk Silicate Earth model • test of unorthodox models of Earth‘s core (is there a breeder reactor ?)

14. Rate of Geo-neutrinos in LENA LENA @ Pyhäsalmi: ~ 1.5 x 103 events / year TNU (1 capture in 1032 protons per year) Scaling KamLAND result to LENA: between 3 x 102 and 3 x 103 events / year G. Fiorentini et al., hep-ph/0401085

15. Geo-neutrinos and LENA Displacement n,e+ for directionality ? e.g. 21 TW core model: Indication (1 s) after a couple of years zenith angle distribution in LENA …thanks to E. Lisi & Baksan group

16. LENA and Proton Decay

17. Event structure in LENA K->m n K Background suppression ~ 10(-4) Acceptance ~ 60%

18. Actual SK limit 2.3 x 1033 y: after 10 years ~ 40 events (< 1 background event) 90%cl limit: 4 x 1034 years T. Marrodan et al., Phys. Rev. D 72, 075014 (2005)

19. Conclusion • LENA: a low energy neutrino observatory • Impact on astro- ,particle-, geophysics • Complementary to Neutrino Telescopes • Feasibility studies very promising • LENA is in the ApPEC roadmap together with ~Mt Water Cherenkov and ~50 kt Liquid Argon Detectors ...thanks to Milla for the kind invitation to talk about LENA