Transcript Document
Parallel Session on Neutrinos
Very brief summary of the field:
• Strong evidence for two different neutrino oscillations
• Consistent picture emerging in terms of a MNSP matrix,
analogous to the CKM matrix in the quark sector
MNSP matrix
Questions/priorities:
• Improve the measurements of the atmospheric (D(m23)2, q23)
and solar (D(m12)2, q12) mixing parameters
•Neutrino mass hierarchy: m1<m2<m3 or m3<m1<m2?
neutrinoless
• Absolute neutrino mass scale?
bb decay
• Fundamental nature of neutrinos: Dirac or Majorana?
• Measure the other MNSP parameters: q13, CP phase d
• LSND result?
• Beyond the beyond…
• Precision measurements of neutrino cross-sections
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CIPANP2003 “Neutrinos” Summary – Berger/Fleming
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May 24, 2003
D(m12)2, q12
Sudbury Neutrino Observatory
• D2O Čerenkov Detector
• Solar 8B neutrinos
• Three signals:
CC (charged current)
EC (elastic scattering)
NC (neutral current)
D+nep+p+eD+nxp+n+ee-+nxe-+ nx
5.3s appearance of nm,t in a ne beam
Full SSM (solar standard model) flux
Talks by Neil McCauley, John Orrell
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May 24, 2003
D(m12)2, q12
KamLAND
• Liquid Scintillator
• Reactor ne
• Inverse b-decay coincidence signal:
ne+pe++n
n+pD+g (2.2 MeV)
• Deficit in rate analysis:
(Nobs–NBG)/Nno-osc =
0.611 0.085 (stat) 0.041 (syst)
• “Standard” ne propagation ruled out
at the 99.95% CL
• Rate+shape analysis sets additional
constraints on mixing parameters
Talk by Bruce Berger
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May 24, 2003
D(m12)2, q12
Solar mixing parameter summary
(two flavor mixing, CPT conserved)
Before SNO 2002
With SNO 2002
LMA preferred
KamLAND rate
LMA confirmed
KamLAND rate+shape
Additional LMA constraints
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May 24, 2003
D(m12)2, q12
Future:
Smirnov hep-ph/0212270
SNO:
Dm2 sensitivity in day/night asymmetry
CC/NC ratio measures q12
(contours on plot)
KamLAND:
Dm2 measurement
with more reactor data
Sensitivity to q12 in reactor phase
(without MSW)
Solar phase measures q12 with 7Be
CIPANP2003 “Neutrinos” Summary – Berger/Fleming
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May 24, 2003
D(m23)2, q23
MINOS
• Accelerator neutrino experiment to
measure “atmospheric” neutrino oscillation
• iron/plastic scintillator, magnetic field
• nt appearance in nm beam
• near and far detectors to control
systematics, backgrounds
• can check both nmnt and nmnt
oscillations in atmospheric neutrinos
• can also search for subdominant
nm-nt mixing
• construction and commissioning ongoing
• first beam late 2004
Talk by Hugh Gallagher
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May 24, 2003
Neutrinoless Double-beta Decay
• If neutrinos are Majorana and not Dirac particles,
double beta decay with no neutrinos is possible
• Rate is proportional to mbb, which depends on
all neutrino masses and mixing angles
(plus new Majorana phases!)
3
mbb Uei mi i
2
i1
• mbb depends on
hierarchy
• Null result doesn’t
rule out Majorana n
• Other beyond SM
possibilities…
Dm2>0
Dm2<0
normal
inverted
Talk by Rabi Mohapatra
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May 24, 2003
Neutrinoless Double-beta Decay
Measurement issues:
Tiny signal
Backgrounds:
• 2nbb – good energy resolution
• radioactivity – very clean materials
• cosmogenic – work underground
Nuclear matrix elements difficult to calculate
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May 24, 2003
0nbb by very different techniques
CUORE/Cuoricino
• 130Te, natural abundance 33.87%, 760 kg
• bolometric detector at 10 mK – 1 MeV DT=0.1mK 1 mV
• 2533 MeV endpoint, 6-8 keV resolution
• Curoricino now running – ~0.4 eV sensitivity in 1 year
• 66-140 meV
Majorana
• 76Ge, 85% enriched, 500 kg
• Germanium ionization detector – mature technology
• 2039 MeV endpoint, 3-4 keV resolution
• 20-70 meV
EXO
• 136Xe, enriched,
• liquid Xe TPC
• extraction and identification of Ba daughter event by event
CUORE talk by Rick Norman
• 2479 MeV endpoint, 2.5% resolution
Majorana talk by Albert Young
• 10’s of meV
EXO talk by Peter Rowson
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May 24, 2003
Reactor measurement of q13
Future Reactor q13 Experiment
Present Reactor Experiments
detector 1
detector 2
• 2-3 detectors
• Variable baseline
• Independent of absolute n flux
• Sensitivity down to
sin22q13 ~ 0.01-2
• Independent of CP phase d,
sign of D(m23)3, matter effects
Diablo Canyon, CA
Talk by Karsten Heeger
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May 24, 2003
Accelerator measurement of q13, d
MNSP Matrix:
~cosd
Probability of nmne depends on
multiple MNSP parameters:
• q13
• CP phase d
• matter effects
~sind
Neutrino and antineutrino running
give complementary measurements
sin22q13
Different experiments also make
complementary measurements
e.g. JHF-SK, NuMI
CIPANP2003 “Neutrinos” Summary – Berger/Fleming
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May 24, 2003
NuMI
• Off-axis neutrinos from MINOS beam – can run simultaneously
• Narrow band 2 GeV beam
• nmne counting experiment
• 50 kton detector, high efficiency, good NC background rejection
• Both neutrino and antineutrino running
• Measurement of nmne, or 20 improvement over CHOOZ limit in 5 years
Energy selected by distance off-axis
Talk by Adam Para
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May 24, 2003
Ultra-long Baseline Experiment?
nm DISAPPEARANCE
Basic parameters:
• BNL Homestake: 2450 km
• Wideband on-axis beam: 1-6 GeV
• High flux: upgrade AGS to 1MW
• 500 kT water Čerenkov detector (e.g. UNO)
BNL-HS 2540 km
250
2
sin 2q23 = 1.0
2
Dm
200
32 =
2
2.5e-3 eV
1 MW, 0.5 MT, 5e7 sec
No oscillations: 13290 evts
150
With oscillations: 6538 evts
Background: 1211 evts
100
A wideband beam at long baseline gives
oscillations vs. energy across the beam
energy range
50
0
0
1
2
3
4
5
6
7
8
9
10
Reconstructed n Energy (GeV)
dCP and sign of Dm2 change shape of observed
oscillation, so they can be measured by
fitting the shape of the spectrum
• sensitivity down to very low q12
Measure everything in one experiment
Talk by Zohreh Parsa
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May 24, 2003
Big question in neutrino
oscillation physics:
too many Dm2!
LSND
Oscillations or something else?
●Karmen
●MiniBooNE
Through what mechanism?
●CPT violation
●sterile neutrinos
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May 24, 2003
LSND
muon DAR
●neutrino beam -- 30m baseline
●n n appearance result
m
e
●
Karmen
●search for n n appearance result
m
e
●set exclusion limit, report joint analysis
●searched for rare muon decays
LSND result from rare muon decay?
signal from LF-viol. m+
decay excluded by Karmen
talk by K. Eitel
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May 24, 2003
MiniBooNE will address the LSND signal
nmne appearance search
Confirm or rule out ne appearance
to 5s -- results in 2005
●results on n disappearance expected
m
this Fall
●cross sections and exotics results
this Fall/Winter
●
talk by T. Hart
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May 24, 2003
CPT violation in neutrino sector
mnmn
LSND
Atmospheric
Solar
KamLAND
CPT talk by G. Barenboim
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May 24, 2003
Add one or more sterile neutrinos
do not interact weakly, but can oscillate with SM neutrinos
3+1 models
Combine results from short baseline
experiments reporting no oscillations
NSBL: Bugey, CHOOZ, CCFR84,
CDHS, Karmen
Overlap with LSND region?
3+2 talk by M. Sorel
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May 24, 2003
Include two or more sterile neutrinos
3+2 models
3+2 talk by M. Sorel
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May 24, 2003
High precision detectors and
high flux neutrino sources
neutrino scattering physics
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May 24, 2003
New Charm production results from CHORUS
Charm hadron
production from nN DIS
NetScan
Data
reconstruct vertex
int.vtx +
D0 decay vtx
D0 production in nN CC interactions
●
Phys. Lett. B 527 (2002) 173-181
c+ production in nN CC interactions
●
Phys. Lett. B 555 (2002) 156-166
Semi-leptonic branching fraction of charm
hadrons nN CC interactions
●
Phys. Lett. B 549 (2002) 48-57
Analysis Ongoing!
●
●
●
Quasi elastic c+ production
Anti-neutrino charm production
Associated charm production in both charged and neutral current
•
Update of results with full statistics
Chorus talk by M. Komatsu
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May 24, 2003
~1 GeV
Neutrino
Cross
Sections
little data at low energies
●unfold nuclear effects
●cross sections important
for osc. experiments
●as probes of other physics
●number of experiments
coming online
●
NC p0 channel
talk by E. Hawker
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May 24, 2003
~2-10 GeV
Neutrino
Cross
Sections
DIS cross sections
Upcoming measurements
●Modeling the DIS to resonance
from MINerVA
region
●
talk by A. Bodek
Push towards generalized neutrino event generators
talk by H. Gallagher
●NEUGEN
Model features of neutrino scattering physics
●NUANCE
Fermi motion, nuclear effects, etc.
●.....
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May 24, 2003
n
n
FINeSE
NC
p
CC
p
n
m
high flux neutrino scattering experiment
●fully active, highly segmented detector
●
m-ID
Measure NC/CC ratio
GAs(Q2=0) Ds
strange spin of the proton
●
NC/CC ratio: (vs Q2)
Ds = -0.1
stat errors only
precision neutrino
cross sections
●
Ds = 0.0
Ds = +0.1
nm disappearance
with MiniBooNE
●
talk by M. Wascko
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proposal submission soon
data taking ~2006
May 24, 2003
At still lower energies:
Modeling of inelastic nN cross sections
●n-deuteron breakup reactions at SNO energies
● pp-fusion at threshold (SSM)
Effective Field Theories n(n) scattering models to NNLO
Fits and constraints:
●Reactor data
●SNO cross section
measurements
●Helioseismology
talk by M. Butler
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May 24, 2003
2
SNS
Low energy
neutrino cross
section measurments
at
Spallation
Neutron Source
Neutrino
Energy Spectrum
0.04
0.035
Neutrino Flux
0.03
SNS
nm
0.025
nm
ne
0.02
0.015
0.01
0.005
0
with 1023 neutrinos per year from SNS
study cross sections of interest to
nuclear astrophysics and nuclear theory
●SuperNova neutrino interaction
cross sections
●
0 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45 48 51
Energy, MeV
CIPANP2003 “Neutrinos” Summary – Berger/Fleming
Detector commissioning ~2008
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May 24, 2003
Fantastically interesting time for neutrino physics
Neutrino masses
●New results from KamLAND and SNO on solar neutrinos
●modeling these low energy neutrino cross sections
2
●Upcoming measurements at SNS
●
Details of the MNSP matrix.....Is q13 small? CP violation?
●
Neutrino-less Double Beta Decay
●
Is the LSND signal due to oscillations? Through what mechanism?
●
Rekindled interest in neutrino scattering physics
neutrinos as probes -- Ds, nuclear effects, DIS to resonance region
●
A lot more to see at CIPANP 2006!
CIPANP2003 “Neutrinos” Summary – Berger/Fleming
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May 24, 2003
It’s over – go home.
CIPANP2003 “Neutrinos” Summary – Berger/Fleming
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May 24, 2003
high precision detection devices have allowed for
new high precision mmnts. -- CHORUS
this combined with high neutrino fluxes have
Rekindled interest in neutrino scattering physics at lower
energies
FINeSE and MINerVA
lots of osc and xsec expts have pushed us towards generalized
cross section monte carlos and cross section models(Eric, hugh's
and aries work)
then need to understand cross sections at lower energy too
because of theory -new facilites at SNS will allow for these measurements.
CIPANP2003 “Neutrinos” Summary – Berger/Fleming
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May 24, 2003
High precision neutrino detection -- new measurements
CIPANP2003 “Neutrinos” Summary – Berger/Fleming
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May 24, 2003
MNSP matrix
mixing between all three active flavors
Ue1 Ue2 Ue3
Um1 Um2 Um3
=
Ut1 Ut2 Ut3
Far off-axis
long baseline
experiments
look for
CP violation
in neutrino sector
Posc(n nb)
ne
nm
nt
three mixing angles
possible CP Violating phase,
d in Ue3
n1
n2
n3
CP + matter,
Dm2 <0
CP
matter effects
modify this!
Dm2>0 Dm2<0
CP + matter,
Dm2 >0
d
Posc(n nb)
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May 24, 2003
LSND?
LSND
• reported nm ne signal
KARMEN
• no evidence of this signal
•MiniBooNE
• accelerator experiment that can
definitively confirm or rule out LSND
• now running (8.5% of target luminosity)
• nm disappearance results this fall
• ne appearance results in 2005
The three different Dm’s cannot be
consistent with three-neutrino mixing
If MiniBooNE confirms LSND, then
things get very interesting…
KARMEN talk by Klaus Eitel
MiniBooNe talk by Terry Hart
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May 24, 2003