neutrino physics, experiments I – Neutrino Mass

João dos Anjos Centro Brasileiro de Pesquisas Físicas

Main SourcesMain Sources• Recent Conferences presentations:Recent Conferences presentations:

• Neutrino 2008Neutrino 2008 – Christchurch, New Zealand. – 25 -31 Mai 2008 – Christchurch, New Zealand. – 25 -31 Mai 2008• Neutrino 2006Neutrino 2006 – Santa Fe, U.S.A. – 13-19 June 2006 – Santa Fe, U.S.A. – 13-19 June 2006

• NuFact 08 – NuFact 08 – Valencia, Spain – 30 June – 4 July 2008Valencia, Spain – 30 June – 4 July 2008• NuFact 06 – NuFact 06 – Univ. Irvine, CA, U.S.A. – 24-30 August 2006 Univ. Irvine, CA, U.S.A. – 24-30 August 2006 • – – Workshop on Neutrino Factories, Superbeams & BetabeamWorkshop on Neutrino Factories, Superbeams & Betabeam

• Absolute values of neutrino masses: status and prospectsAbsolute values of neutrino masses: status and prospectsS.M.Bilenky et al; Physics Reports 379 (2003), 69-148S.M.Bilenky et al; Physics Reports 379 (2003), 69-148

• Neutrino masses and mixing: evidence and implicationsNeutrino masses and mixing: evidence and implicationsM.C. Gonzalez-Garcia – Rev. Modern Physics,75, 2003M.C. Gonzalez-Garcia – Rev. Modern Physics,75, 2003

• CERN Summer Student School 2005CERN Summer Student School 2005 J.J. Gómez-Cadenas – IFIC/U. ValenciaJ.J. Gómez-Cadenas – IFIC/U. Valencia

Measuring the Neutrino Mass

• Direct neutrino mass measurements

• Double Beta Decay

• Astrophysical limits

Measuring the Neutrino Mass

• Oscillations tell us about neutrino mass differences, but what about the masses themselves?

• Three kinds of experiments:• Precise experiments on the beta decay of tritium in order

to measure directly the average neutrino mass.

• Neutrinoless double-beta decay experiments sensitive to other combination if neutrinos are their own antiparticle (Majorana particles)

• Precision studies of the distribution of the cosmic microwave background and large-scale structures of the universe revealed by clusters of galaxies

R. Wigmans

NEMO-3

A. Piepke

A. Piepke

mm 0.90 e V0.90 e V

m

m

m

m 0. 90 eV

2.11 eV

1.8 eV

1.4 eV

M. Cirelli, Nufact 06

Evidences of DM• Rotation curves of galaxies and

clusters

• Weak modulation of strong lensing, Oort discrepancy, weak gravitational lensing, velocity dispersions of dwarf spheroidal galaxies and of spiral gallaxy satellites…

Need non-luminous matter

Black-holes, brown dwarfs, white dwarfs, giant planets, neutron stars …?

Neutrinos from WIMP annihilations

i

ii

ann

dE

dNBR

RdtdEd

dN

24

Distance source-detector

Branching ratio into annihilation channel i

Neutrino spectrum from annihilation channel i

Conclusions• Neutrino detectors can test DM properties

• Searches for neutrinos from DM annihilations/decays in celestial bodies could constitute powerful probes of DM properties

• Cherenkov neutrino detectors/telescopes are counting experiments and could only provide limited information

• Future neutrino detectors (MIND, TASD and LArTPC) will have very good energy resolution for 10’s GeV

• Reconstructing the neutrino spectra → information on DM mass, annihilation branching ratios and DM-proton cross section

• Due to small size, only suitable for large spin-dependent cross sections and neutrinos from annihilations in the Sun, but complementary to Neutrino Telescopes (with higher threshold)

• Neutrino detectors can set model-independent bounds on the DM annihilation cross section and on the DM lifetime

= 0.05 eV