NuHorizons 09: Summary Talk
Amitava RaychaudhuriHarish-Chandra Research Institute
Allahabad, India
January 2009
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 2
Homi J. Bhabha
1909-1966
Scientist,
Visionary,
Institution
builder
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 3
27 May 2008, Neutrino 08
Plan
• Neutrino Oscillation • Mass models• High energy neutrinos• Supernova neutrinos• Dark matter• INO
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 4
Highlight!
Fog!
Flight
Cancellations
Train
delays
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 5
ApologiesMissed talks by:Rathin Adhikari, Biswajit Adhikary, Zackaria Chacko, Sovan Chakraborty. SandhyaChoubey, Paramita Dey, Pasquale DiBari,Rikard Enberg, Raj Gandhi, Thomas Hambye, Mary Hall Reno, Werner Rodejohann, Sourov Roy, Atsushi Watanabe, Terribly sorry, folks!
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 6
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 7
Neutrino parameters
• Three masses m1, m2, and m3
• Three mixing angles: θ12, θ23, and θ13
• CP phases δ, α, β• Known at the moment
a) Only relative mass splitting
b) Sum of the masses
c) θ12 and θ23
oscillation experiments ν-mass 0νββ cosmology/astrophysics
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 8
Status: Δm212 and θ12
Thanks to S. Choubey
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 9
Status: Δm231 and θ23
Thanks to S. Choubey
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 10
OPERA• OPERA: CERN to LNGS νντ through τ detection• Emulsion Cloud Chamber technique• Emulsion + electronic detection• First results
Thanks to A. Paoloni.
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 11
Borexino• 100 Tons• Purity is critical:
Po, Kr the last hurdles• Environmental issue: delay• 192-day results consistent with
MSW LMA• Get Be flux to 5%
Thanks to R.S. Raghavan
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 12
MIPP
• Main Injector Particle Production experiment
• Test Non-perturbative QCD, scaling laws, shower simulation, etc.
• Relevant for MiniBoone, atmos. nu, nu factories
• Data (05-06) analysis on
Thanks to R. Raja
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 13
If 13 is vanishingly small….
atm = 13 - c212 12
normal inverted hierarchyUsually used 13 -13
Correct only for large θ13 Possible to find hierarchy using
atm nu
For small θ13 one must usetwo different expts
Advantage of Long baseline expt
Thanks to P. Ghoshal
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 14
Neutrino mass changes with epoch
Acceleron field contribution to mν besides type I see-saw
As neutrino density decreases 2nd term begins to dominate
Effect mimics dark energy with
weff < -1
Not ghosts or vac instability
Rather support for MAVAN
Mass varying neutrinos
Thanks to K. Dutta
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 15 15
Effective operator for neutrino mass
There are three tree level realizations: E. Ma, Phys. Rev. Lett, 81, 1171 (1998)
(I) (II)
(III) Replacing in (I) by heavy Majorana fermion triplet
S. Weinberg, Phys. Rev. Lett, 43, 1566 (1979)
Thanks to R. Adhikari
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 16
Post-sphaleron baryogenesis
• PS224 Quark-lepton symmetry Δ(1,3,10) Δνν ≡ S
• S develops a vev: 10-100TeV• Baryogenesis from S-decay, neutron-antineutron oscillations• Neutrino masses through Type-II see-saw
Thanks to B. Dev
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 17
Phenomenology of Type III see-saw
• Triplets under SU(2), Σ couples to gauge bosons. LHC production up to 1.5 TeV.
• Σ+c can mix with charged
lepton. Rare decays, e.g.,
→e γ, →eee probe up to 200 TeV.
• Decay branching ratios are
important
• L-violation, leptogenesisThanks to T. Hambye
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 18
TeV-scale see-saw
Thanks to Sourov Roy
NMSSM and R-parity violation
Sneutrino vev, LSP decay signals
Testable at LHC!
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 19
See-saw models with a Z’Models with a Z’ under which RH neutrinos (TeV-scale) are charged.
TeV scale Z’, when produced, will decay to NRNR which decay to charged leptons (could be same sign)
TeV scale Majorana NR carry additional lepton number violation -- flavour dependent -- and erase baryon asymmetry created earlier.
Prevention of washout yields an UPPER bound on NR mass. e.g., Type I: 300 GeV for degenerate case and 1 TeV for IH. No bound for NH. Similar (but tighter) constraints for Type III
Testable at the LHC
Thanks to. Z. Chacko
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 20
Four-zero textures and symmetry
• 126 four-zero texture mass matrices possible
• Two compatible with symmetry
• Predictive: θ23 = π/4, θ13 =0 Parametrised by k,k’, α
Thanks to B. Adhikary
R = 3.2 x 10-2, θ12 = 34o
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 21
Triplet Higgs, S3 symmetry, Lepton masses
• Also add discrete Z3 or Z4 symmetry• 2 Higgs triplets: Type II see-saw for nu mass• Mild breaking of τ symmetry: small θ13
• LHC charged higgs signals? Thanks to M. Mitra
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 22
Two-loop neutrino masses in SUSY
• Neutrino masses from R-parity violating SUSY and sqauark non-degeneracy. Large couplings may contradict ν-mass.
• Sets of couplings may be chosen so that 1-loop vanishes.• Two loops do the job (one diagram shown)
Thanks to P. Dey
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 23
RG evolution for Type III see-saw
Type III see-saw relies on SU(2) triplet fermions
They contribute to gauge coupling evolution as well as to Yukawa and Higgs self couplings affecting neutrino mass and mixing evolution.
Calculation in Rξ gauge ensures gauge invariance
Running of MΣ Is significant.
Threshold effects and Majorana phases are important
CP phase δ undefined at θ13 = 0. Careful handling using Jarlskog J shows there is no singularity.
Thanks to. S. Ray
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 24
Deviations from tri-bimaximal mixing
• Deviations from TBM• Different options• Other patterns?
Thanks to W. Rodejohann
θ13 ≠0?
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 25
Stable right-handed neutrino could be warm dark matter
See-saw prefers heavier νR unless Dirac mass is chosen small
Consider three RH neutrinos of which one is heavy and the others light. Lightest (TeV scale or more) is long lived and a dark matter candidate.
Abundance is a difficulty
Can abundance be enhanced through oscillations from the other light state?
Yes, through dimension-5 operators
Dark matter from νR mixing
Thanks to P. DiBari
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 26 26
n1 (n4) is the U(1) charge of (u,d) and (ν,l) doublets.
Anomaly cancellation has to be respected
If X gauge boson is observed at LHC , then r may be determined from its decay branching fraction
Thanks to R. Adhikari
Models with extra U(1) symmetry
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 27 27
Rare lepton decays are interesting Quark sector is suggestive
Experiments (e.g, BaBar and Belle) are pushing the boundary
Constrain MSSM (slepton mixing)? Neutrino masses (See-saw + MSSM)?
Thanks to A. Ibarra
Rare τ decays
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 28
Neutrino cross sections
Low energy νN cross sections have significant uncertainty(next slide)
At UHE the cross sections are extrapolation based.
Detailed exposition
Thanks to M.H. Reno
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 29
LO+TMC
Low Q extrapolations, from NLO+TMC, with CKMT (and Bodek et al) extrapolation.
NLO + TMC, no special low Q extrapolation.
MHR, Phys. Rev. D74 (2006)
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 30
New era in high energy neutrino astronomy
Neutrino fluxes better estimated through TeV gamma measurements and UHE cosmic ray information
UHE neutrinos probe BSM physics: Extra dimensions, black holes, …
Neutrino flavour ratios carry important clues
Radio detection beyond GSM is a possibility worth exploring
High Energy ν
Thanks to R. Gandhi
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 31
Prompt neutrinos
High energy neutrinos from
heavy quark (c, b) decay:
a) In atmospheric flux
b) From astrophysical sources
Smaller cross section
Harder spectrum
New, improved QCD calculation
Thanks to R. Enberg
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 32
Prompt neutrino from charm decay from supernova
Slow jets: Like GRB but lower Lorentz boost
Resulting diffuse background is small, but individual point sources possible
Boosted from comoving frame to earth frame
TeV energy neutrinos
May be detectable in km3 detectors
Thanks to A. Watanabe
Charm decay ν from supernova
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 33
Diffuse supernova nu backgroundDSNB from supernova explosions in the past.
Depends on supernova rate. SN neutrino spectrum required.
Collective effects – ν-ν interaction driven – are important.
Complete swapping for IH, No effect for normal hierarchy.
MSW also has to be included farther out
Thanks to S. Chakraborty
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 34
INO site
Pushep: 11.5N 76.6E
(Near Ooty Hill station)
Masinagudi 6.5km
Mysore 96.5km
Bangalore 350km
1km rock coverage
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 35
Schematic of 50 kton ICAL
Large Mass
Good tracking and energy
resolution
Good directionality
Charge ID
Ease of construction
6cm thick Fe plates
2.5cm gap for RPC trays
2mx2m RPCs interleaved
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 36 36
Development of large area glass RPCs
Thanks to N.K. Mondal
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 37
Absolute neutrino mass measurement from 0ν2β expts ~ 0.03 eV
Determine sign of Δm231. CP-phase δ
Pin down θ13. Hints of non-zero value?
Sterile neutrinos? Why light, even if they are there?
Km3 detectors for UHE neutrinos
Much activity in mass models, tribimaximal, testability
Supernova neutrinos, Leptogenesis, …
Looking forward to NuHoRIzons 2010
Looking ahead
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 38
Summary TalkA. Raychaudhuri
January 09, 2009 NuHoRIzons 09 39
Thank you