Transcript LENA - Istituto Nazionale di Fisica Nucleare

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
100m
30m
LENA
Muon
veto
50 kt liquid
scintillator
detector
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
• 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
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):
Large systematic uncertainties
Lawrence Livermore – LL
UV (blue), Ha (green) and FIR
(red) are impeded by dust
extinction
Keil, Raffelt, Janka – KRJ
Thompson, Burrows, Pinto - TBP
Supernovae Relic ne
SRN Rate
(between 9.5 and
30 MeV):
40 – 77 / (10 a)
ne  p  e  n

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
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...
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 ?)
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%
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