LENALENALow Energy Neutrino Low Energy Neutrino

AstrophysicsAstrophysicsL. 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 Delta

Scintillator solvent: PXE, or PXE/mineral oil mixtureScintillator solvent: PXE, or PXE/mineral oil mixture

• non hazardous, flashpoint 160° C non hazardous, flashpoint 160° C easy handlingeasy handling

• density up to 0.99density up to 0.99 high self shielding high self shielding

• high light yieldhigh light yield low energy eventslow energy events

• low background level U, Thlow background level U, Th solar solar geo geo , snr , snr

Muon veto

30% coverage up to ~60% (light cones)

LENA

50 kt liquid scintillator detector

100m

30m

• transport transport of PXE via railwayrailway

• loadingloading of detector via direct pipeline pipeline

• no fundamental no fundamental securitysecurity problem problem with PXE with PXE

• no fundamental problem for excavationexcavation

• LENA is feasible in Pyhäsalmi !LENA is feasible in Pyhäsalmi !

LENA at CUPP

Scintillator for LENAScintillator for LENACTF at Gran Sasso (BOREXINO)

Absorption- and Scattering lengths at TU München

~ 100 pe / MeV for an event at the center

up to ~ 200 pe / MeV with light cones should be possible

Coverage 30%

Supernovae Relic Supernovae Relic ee

3 models (different spectral shapes):

Lawrence Livermore – LL

Keil, Raffelt, Janka – KRJ

Thompson, Burrows, Pinto - TBP

Large systematic uncertainties

UV (blue), H (green) and FIR (red) are impeded by dust extinction

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)

Supernovae Relic Supernovae Relic ee

nepe

Supernovae Relic Supernovae Relic ee

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 NeutrinosSupernova NeutrinosAssumption: Supernova II with 8 solar masses at 10 kpc distance

e flux and spectrum

e flux and spectrum

Supernova NeutrinosSupernova Neutrinos

Total neutrino flux

Total energy spectrum

Supernova and neutrino properties

„Wiggles“ in the e spectrum observable

• if spectra or fluxes of SN neutrino flavors differ

• if neutrinos pass the Earth before entering LENA

yes no

Smirnov, Dighe, Raffelt...

Solar NeutrinosSolar Neutrinos

• High statistic ( ~ 5.4 x 103 / day ) 7Be + e + 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 e (13C,13N) e- reaction ( ~ 103 / year )

spectroscopy of 8B- at energies below 5 MeV

(A. Ianni et al., hep-ph/0506171)

LENA Fiducial Volume for solar : 18 x 103 m3

Test of MSW effectTest of MSW effect

7Be pep CNO

8B 8B via 13C

MSW

effect

Geo NeutrinosGeo 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 ?)

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

Rate of Geo-neutrinos in LENA

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

Geo-neutrinos and LENAGeo-neutrinos and LENA

Displacement n,e+ for directionality ?

zenith angle distribution in LENA

e.g. 21 TW core model:

Indication (1 ) after a couple of years

…thanks to E. Lisi & Baksan group

LENA and Proton DecayLENA and Proton Decay

K

K

Event structure in LENA

Background suppression ~ 10(-4)

Acceptance ~ 60%

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)

ConclusionConclusion

LENA: a low energy neutrino observatoryLENA: a low energy neutrino observatory

Impact on astro- ,particle-, geophysicsImpact on astro- ,particle-, geophysics

Complementary to Neutrino TelescopesComplementary to Neutrino Telescopes

Feasibility studies very promisingFeasibility studies very promising

LENA is in the ApPEC roadmapLENA is in the ApPEC roadmap

together with ~Mt Water Cherenkov and together with ~Mt Water Cherenkov and ~50 kt Liquid Argon Detectors~50 kt Liquid Argon Detectors

...thanks to Milla for the kind invitation to talk about LENA