Closing remarks

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Closing remarks

• G. Ross Models of Neutrino Mass
• S. Abel Pseudo-Dirac neutrinos and leptogenesis
• S. Palomares-Ruiz Resolving the LSND Anomaly
• S.Choubey Supernova seismology and sterile
  neutrinos
• A.Vacheret The challenges of the T2K 280m near
  detector
• S.Cartwright ANTARES
• R.Saakyan Experimental review of double beta
  decay
• S.Soldner-Rembold The COBRA Double Beta Decay
  Experiment
• P.Harrison Leptonic Mixings from a variational
  principle
• C.Jarlskog On quark and lepton masses and
  mixings

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Unravelling the origin of mass..
G.Ross
Many possibilities, many parameters
difficult (impossible) unless we are lucky!
Small in quark sector, large in lepton sector?
Mixing
Non Abelian Structure?
Bi-Tri Maximal Mixing
Harrison, Perkins, Scott ansatz
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Vacuum alignment sequential dominance
Red terms dominate
SFK 98-
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Vacuum alignment sequential dominance
Red terms dominate
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SFK hep-ph/0506297
Real vacuum alignment of SO(3) and Pati-Salam
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Effect of small charged lepton mixing angles
Antusch, SFK 05
e.g. Tri-bimaximal 35.26
If 13 angles are small have SUM RULE
q12q13cos(d -p)¼ qn12
q13 and d then come from the charged lepton sector
e.g.
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d is predicted
e.g. tri-bimaximal neutrino mixing plus
quark-lepton unification leads to
? gives prediction for q12 as function of d
Current 3s experimental range
Tri-bimaximal value predicts maximal CP
violation! (NOT zero CP violation!)
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S.Abel
Alternatively can get small Yukawa couplings
directly from asymmetric compactifications of
string theory Antusch, Eyton Williams,SFK
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S.Palomares-Ruiz Resolving the LSND Anomaly

• With and without sterile neutrinos
• With one and with more than one sterile
• With and without neutrino oscillations
• With and without CPT violation
• With non-standard and with standard processes
• With and without extra dimensions
• With problems and with problems
• Those we like and those we dont like
• Those we have proposed and those we havent
  proposed
• No solution

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A.Vacheret The Challenges of the T2K 280m near
detector
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Dark matter search in mSUGRA models S.Cartwright

• Sun is best standard source
• up to several thousand muons per km2 per year

mainly WW and ZZ
mainly tt
SuSpect DarkSUSY, Nezri et al
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R.Saakyan Experimental review of neutrinoless
double beta decay
Theory recent developments in NME calculations
e.g. Rodin et al nucl-th/0503063 Mo100 ME to
20! Experiment two approaches to detect
electrons sourcedetector, or separate
calorimeter Heidelberg-Moscow ltmgt0.1-0.9eV (due
to NME) _at_2.5\sigma Current experiments NEMO-3,
Cuoricino ltmgt0.2-0.6eV by 2008 Current NEMO-3
ltmgt0.3-2.8eV Future experimentsincl. UK expts.
SuperNEMO, COBRA GERDA (approved) Ge-76 phase I
confirm/rule out Klapdor in 3-years GERDA phase
III (possible merger with Majorana) ltmgt
.03-.09eV CUORE (approved) 0.03-0.1, EXO /
SuperNEMO ltmgt0.04-0.08ev
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S.Soldner-Rembold SuperNEMO (UK RD)
SuperNEMO extrapolation of NEMO-3 by an order
of magnitude Mo100?Se82 (PPARC RD approved
05) Challenges energy resolution (thin wires),
choice of isotope, background (photon?ee-) Sites
Boulby mine (low background from potash), Gran
Sasso Can see event by event
B. Morgan COBRA (UK RD)
COBRA Cadmium Tellurium 0-neutrino Beta decay
Research Apparatus Semiconductor sourcedetector,
CZT crystals, clean, good energy resolution Test
facilities in Gran Sasso to study
background 64-array under construction
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P.Harrison Lepton mixings from a variational
principle

• Dirac masses
• Jarlskog covariance MNS is invariant under a
  change of basis
• Write everything in terms of basis invariants
  e.g. CP violating observable J
• NuSM attempt to explain lepton mixing by
  extremising a flavour-symmetric Jarlskog
  invariant
• Promote Yukawa couplings to dynamical variables
• Not yet a theory

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C.Jarlskog on quark and lepton masses and mixings
Invariants of mass matrices are the only
reliables Texture zeros, Input texture zeroes,
Output predictions An important discovery should
be expressible in an invariant form A new
parametrisation of a unitary matrix
generalisable to nxn, convenient if there is a
hierarchy
There may be a preferred basis if there is a
broken family symmetry determined by vacuum
alignment (the most convenient basis to work in)
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Experimental Summary
Seven experimental challenges for neutrino
physics 1. Count the number of neutrinos 2.
Measure the neutrino mass scale 3. Determine the
sign of the mass ordering 4. Measure the
deviation of q23 from maximal 5. Measure q13 6.
Measure d 7. Measure the deviation of q12 from
tri-bimaximal mixing
MiniBooNE - soon
(b b)0n and KATRIN
Nufact/beta/super
Hyper-K
LBL ? Reactor ?Nufact/beta/super
Nufact/beta/super
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TOE (M-theory)
Theory Summary
GUTFlavour theory
See-saw model
Leptogenesis
No direct link (need to go via see-saw model)
RGE
Neutrino masses and mixings
Muon flavour violation
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Future of UK Neutrino Network

• Next meeting in April at RAL after ISS meeting?
• Grant expires in Spring 06 should we continue?
• Jointly with experimentalists?