Low Energy Neutrino Astrophysics LENA LENA Delta Low Energy Neutrino Astrophysics 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

LENA 50 kt liquid scintillator detector 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

LENA at CUPP LENA is feasible in Pyhäsalmi ! 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 !

Scintillator for LENA ~ 100 pe / MeV for an event at the center 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

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

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

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…

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

Supernova Neutrinos Total neutrino flux Total energy spectrum

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...

LENA Fiducial Volume for solar n: 18 x 103 m3 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)

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

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 ?)

G. Fiorentini et al., hep-ph/0401085 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

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

LENA and Proton Decay

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

T. Marrodan et al., Phys. Rev. D 72, 075014 (2005) 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)

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