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Neutrino oscillation physics with Neutrino oscillation physics with superbeams and neutrino factoriessuperbeams and neutrino factories
Nu HoRIzons workshop Nu HoRIzons workshop HRI, IndiaHRI, India
February 13-15, 2008February 13-15, 2008
Walter WinterWalter WinterUniversität WürzburgUniversität Würzburg
Feb. 14, 2008 Nu HoRIzons 2008 - Walter Winter
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ContentsContents IntroductionIntroduction SuperbeamsSuperbeams
– What can we expect from 1What can we expect from 1stst generation experiments? generation experiments?– Examples for upgrade optionsExamples for upgrade options
Neutrino factoryNeutrino factory– IDS-NF baseline setup 1.0IDS-NF baseline setup 1.0– Detector requirements/detector optimizationDetector requirements/detector optimization– Physics with a very long baseline (to India?)Physics with a very long baseline (to India?)– Requirements for non-standard measurements/Requirements for non-standard measurements/
physics case for the silver channel?physics case for the silver channel? Summary and conclusionsSummary and conclusions
Will not talkabout beta beams!
Contents reflecta biased selection
of aspects!
Feb. 14, 2008 Nu HoRIzons 2008 - Walter Winter
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Evolution of Evolution of 1313 discovery limit? discovery limit?
Specific scenarioSpecific scenario Bands reflect Bands reflect
dependence on dependence on CPCP
(from: FNAL Proton Driver Study)
GLoBES 2005
(NOvA)
Feb. 14, 2008 Nu HoRIzons 2008 - Walter Winter
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Appearance channelsAppearance channels
(Cervera et al. 2000; Freund, Huber, Lindner, 2000; Huber, Winter, 2003; Akhmedov et al, 2004)
Antineutrinos:Antineutrinos: Magic baseline:Magic baseline: Silver:Silver: Platinum:Platinum:
Feb. 14, 2008 Nu HoRIzons 2008 - Walter Winter
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Superbeams: ConceptSuperbeams: Concept Conventional neutrino beamsConventional neutrino beams::
Neutrino production by pion, kaon decays Neutrino production by pion, kaon decays (obtained from protons hitting a target)(obtained from protons hitting a target)
„„Super“-beamsSuper“-beams: T2K, NOvA: T2K, NOvA– Higher target powers O(1 MW)Higher target powers O(1 MW)– Larger detectors O(30 kt)Larger detectors O(30 kt)– Off-axis technology (for BG Off-axis technology (for BG
suppression, lower E)suppression, lower E) „„Super“-Superbeams, superbeam Super“-Superbeams, superbeam
upgradesupgrades: WBB, T2KK, CERN-: WBB, T2KK, CERN-Memphys, NuMI*, …Memphys, NuMI*, …– Even higher target powers O(4 MW)Even higher target powers O(4 MW)– Even larger detectors O(100-500 kt)Even larger detectors O(100-500 kt)– On- or off-axis technologyOn- or off-axis technology– „„Super“ pricySuper“ pricy
For leading atm. params
Signal prop. sin2213
Contamination
Feb. 14, 2008 Nu HoRIzons 2008 - Walter Winter
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Running example for beams: MINOSRunning example for beams: MINOS Measurement of atmosphericMeasurement of atmospheric
parameters with high precisionparameters with high precision Flavor conversion ?Flavor conversion ? Fermilab - Soudan
L ~ 735 km
Far detector: 5400 tNear detector: 980 t
735 km
Beam line
Feb. 14, 2008 Nu HoRIzons 2008 - Walter Winter
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Perspectives for MH and Perspectives for MH and CPCP
for the coming 5 to 10 years?for the coming 5 to 10 years? A mass hierarchy or CP violation measurement A mass hierarchy or CP violation measurement
will be unlikely or impossible fromwill be unlikely or impossible from– Beams+Reactor experimentsBeams+Reactor experiments– Any other source alone (supernova etc.) Any other source alone (supernova etc.)
(from: Huber, Lindner, Rolinec, Schwetz, Winter, 2004)(from: Huber, Lindner, Rolinec, Schwetz, Winter, 2004)
Feb. 14, 2008 Nu HoRIzons 2008 - Walter Winter
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Superbeam upgrades: ExamplesSuperbeam upgrades: Examples
ExposureExposure: : Detector mass [Mt] xDetector mass [Mt] xTarget power [MW] xTarget power [MW] xRunning time [10Running time [1077s]s]
Bands: variation of Bands: variation of systematical errors: systematical errors: 2%-5%-10%2%-5%-10%
Dots: Nominal LDots: Nominal L Typical Typical CPCP, 3, 3(Barger, Huber, Marfatia, Winter, hep-ph/0610301, hep-ph/0703029)
discovery
Feb. 14, 2008 9
Luminosity scalingsLuminosity scalings If If 1313 found by found by
superbeams:superbeams:– WBB and T2KKWBB and T2KK
can measure CPV, can measure CPV, MHMH
– NuMI requires NuMI requires Lumi-upgrade Lumi-upgrade (ProjectX?)(ProjectX?)
Systematics impact Systematics impact least for WBB; best least for WBB; best physics concept?physics concept?
Feb. 14, 2008 Nu HoRIzons 2008 - Walter Winter
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Baseline-OA-OptimizationBaseline-OA-OptimizationExample: NuMI-like beam Example: NuMI-like beam 100kt liquid argon 100kt liquid argon
CP=-/2
CP=+/2
sin22 CP violation Mass hierarchy
(Barger, Huber, Marfatia, Winter, 2007)
Constraintfrom
NuMIbeam
FNAL-DUSELWBB
Ash RiverOA,NOvA*
Feb. 14, 2008 Nu HoRIzons 2008 - Walter Winter
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Large Large 1313 case case… for the sensitivity to CP violation… for the sensitivity to CP violation
Superbeam upgrades can easily outperform a „straightforward“ NFSuperbeam upgrades can easily outperform a „straightforward“ NF How can one optimize a neutrino factory for large How can one optimize a neutrino factory for large 1313??
(Barger, Huber, Marfatia, Winter, hep-ph/0703029)
=350 beta beamBurguet-Castell et al, 2005
Neutrino factory3000 +7500 km
50 kt + 50 kt
NuMI beam to 100kt LArTPC
FNAL - DUSEL 100kt LArTPC
270kt+270ktWC detector
Feb. 14, 2008 12
Neutrino factoryNeutrino factory Ultimate “high precision” instrument!?Ultimate “high precision” instrument!? Muons decay in straight sections of storage ringMuons decay in straight sections of storage ring Technical challenges: Target power, muon cooling, charge Technical challenges: Target power, muon cooling, charge
identification, maybe steep decay tunnelsidentification, maybe steep decay tunnels
For leading atm. params
Signal prop. sin2213
Contamination ISS
(Geer, 1997; de Rujula, Gavela, Hernandez, 1998; Cervera et al, 2000)
Feb. 14, 2008 Nu HoRIzons 2008 - Walter Winter
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NF optimization potential (ISS)NF optimization potential (ISS)
Optimized NuFact: Excellent Optimized NuFact: Excellent 1313 reach for both MH and CPV reach for both MH and CPV But: For sinBut: For sin22221313 ~ 10 ~ 10-2-2, , =350 beta beam (L=730 km) better=350 beta beam (L=730 km) better
3
(Huber, Lindner, Rolinec, Winter, hep-ph/0606119; -beam: Burguet-Castell et al, hep-ph/0503021)
E=50 GeV
E=20 GeV
Feb. 14, 2008 Nu HoRIzons 2008 - Walter Winter
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IDS-NF launched at NuFact 07IDS-NF launched at NuFact 07International design study for a neutrino factoryInternational design study for a neutrino factory
Successor of the International Scoping Study for a „future Successor of the International Scoping Study for a „future neutrino factory and superbeam facility“:neutrino factory and superbeam facility“:Physics case made in physics WG report (~368 pp) Physics case made in physics WG report (~368 pp) (arXiv:0710.4947 [hep.ph])(arXiv:0710.4947 [hep.ph])
Initiative from ~ 2007-2012 to present a design report, Initiative from ~ 2007-2012 to present a design report, schedule, cost estimate, risk assessment for a neutrino schedule, cost estimate, risk assessment for a neutrino factoryfactory
In Europe: Close connection to „EuroIn Europe: Close connection to „Eurous“ proposal us“ proposal within the FP 07; currently ranked #1, negotiating contract within the FP 07; currently ranked #1, negotiating contract
In the US: „Muon collider task force“In the US: „Muon collider task force“How can a neutrino factory be „upgraded“ to a muon How can a neutrino factory be „upgraded“ to a muon collider?collider?
Feb. 14, 2008 Nu HoRIzons 2008 - Walter Winter
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IDS-NF baseline setup 1.0IDS-NF baseline setup 1.0 Two decay ringsTwo decay rings EE=25 GeV=25 GeV
5x105x102020 useful muon useful muon decays per baselinedecays per baseline(both polarities!) (both polarities!)
Two baselines:Two baselines:~4000 + 7500 km~4000 + 7500 km
Two MIND, Two MIND, 50kt each50kt each
Currently: MECC at Currently: MECC at shorter baselineshorter baseline (http://www.hep.ph.ic.ac.uk/ids/)(http://www.hep.ph.ic.ac.uk/ids/)
Feb. 14, 2008 Nu HoRIzons 2008 - Walter Winter
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IDS-NF baseline setup 1.0 descriptionIDS-NF baseline setup 1.0 description
55% E55% E0.50.5 energy resolution energy resolution Detection threshold and Detection threshold and
backgrounds from new backgrounds from new simulationsimulation
2.5% signal uncertainty, 2.5% signal uncertainty, 20% BG uncertainty20% BG uncertainty
5 yr + 5 yr running time5 yr + 5 yr running time Silver channel: 10 kt Silver Silver channel: 10 kt Silver
from from hep-ph/0606119 hep-ph/0606119 (Autiero et al MECC)(Autiero et al MECC)
(IDS
-NF
baseline specification)
Old analysis/det.
Baseline detector
New analysis (diff. L)
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IDS baseline IDS baseline performanceperformance
for discoveryfor discovery
… evaluated with GLoBES!… evaluated with GLoBES!
3
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Two-baseline optimization revisitedTwo-baseline optimization revisited
Sensitivity for all Sensitivity for all sinsin22221313>10>10-3.4 -3.4 ((1313),), sinsin222213 13
>10>10-3.8 -3.8 (MH, CPV)(MH, CPV) (5 (5) ) for the shown for the shown performance performance indicatorindicator
True True CPCP chosen chosen close to worst close to worst casecase
Robust optimum Robust optimum for ~ 4000 + for ~ 4000 + 7500 km7500 km
(Kopp, Ota, Winter, in prep.)
IDS baseline
Optimum
Feb. 14, 2008 Nu HoRIzons 2008 - Walter Winter
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Consequences for detector locationsConsequences for detector locations Long baseline: L ~ 7000 - 9000 km good choice:Long baseline: L ~ 7000 - 9000 km good choice:
CERN-INO?
Feb. 14, 2008 Nu HoRIzons 2008 - Walter Winter
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Magic baseline - detector requirementsMagic baseline - detector requirements IDS-NF baseline requires two MINDs as specifiedIDS-NF baseline requires two MINDs as specified What ifWhat if
– The long baseline detector is smaller?The long baseline detector is smaller?– The CID capabilities do not allow for the specified The CID capabilities do not allow for the specified
threshold/backgrounds?threshold/backgrounds?
Quality moreimportant than
quantity!
Feb. 14, 2008 Nu HoRIzons 2008 - Walter Winter
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Large Large 1313: Low-E (low budget?) NuFact: Low-E (low budget?) NuFact Use magnetized detector with low threshold to Use magnetized detector with low threshold to
allow for lower Eallow for lower E(Bross, Ellis, Geer, Mena, Pascoli, 2007)(Bross, Ellis, Geer, Mena, Pascoli, 2007)
Combine with superbeam? – NF-Superbeam:Combine with superbeam? – NF-Superbeam:
(Huber, Winter, 2007)
Or use second target?
*
Feb. 14, 2008 Nu HoRIzons 2008 - Walter Winter
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Low-E NuFact: CPV comparisonLow-E NuFact: CPV comparison
NF-SB (ENF-SB (Epp=28 GeV, E=28 GeV, E=5 GeV, L=1250 km) can outperform =5 GeV, L=1250 km) can outperform any of the discussed setups except from beta beamany of the discussed setups except from beta beam
But: Luminosity choice for beta beam arbitrary in this context!But: Luminosity choice for beta beam arbitrary in this context!Parameters: Parameters: =350, L=712 km, 5 yr x 5.8 10=350, L=712 km, 5 yr x 5.8 101818 useful useful 66He decays/yr, 5 yr x 2.2 He decays/yr, 5 yr x 2.2 10101818 useful 18 useful 18NeNe decays/yr decays/yr (Burguet-Castell et al, 2005)(Burguet-Castell et al, 2005)
(Huber, Winter, 2007)
Ep=28 GeV500 kt WC
Physics with a very longPhysics with a very longneutrino factory baselineneutrino factory baseline
CERN-INO???CERN-INO???
Feb. 14, 2008 Nu HoRIzons 2008 - Walter Winter
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Precision measurementsPrecision measurements
(Gandhi, Winter, 2006)(Huber, Lindner, Winter, 2004)
CP precision 13 precision
CP dep.
3
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Further applications:Further applications:Matter density measurementMatter density measurement
IdeaIdea: Treat : Treat as yet another as yet another oscillation parameter to be oscillation parameter to be measured; marginalize measured; marginalize oscillation parameters!oscillation parameters!
Comes „for free“ from very Comes „for free“ from very long baseline!?long baseline!?
Two different models:Two different models:1.1. Measure Measure RefRef
2.2. Measure Measure LMLM
(lower mantle density)(lower mantle density) (Winter, 2005; Minakata, Uchinami, 2006;
Gandhi, Winter, 2006)
Lower mantle density
Feb. 14, 2008 Nu HoRIzons 2008 - Walter Winter
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Matter density: Geophysical use?Matter density: Geophysical use? Example:Example:
Plume hypothesisPlume hypothesis A precisionA precision
measurement << 1%measurement << 1%could discriminatecould discriminatedifferent geophysicaldifferent geophysicalmodelsmodels
Possible selectorPossible selectorof detectorof detectorlocations?locations?
(Courtillot et al., 2003; see talk from B. Romanowicz, Neutrino geophysics 2005)
Feb. 14, 2008 Nu HoRIzons 2008 - Walter Winter
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Results for one-parameter measurementResults for one-parameter measurement Assume that only one Assume that only one
parameter measuredparameter measured For large For large 1313, < 1% , < 1%
precision at 3precision at 3 Indep. confirmed byIndep. confirmed by
Minakata, UchinamiMinakata, Uchinami(for one baseline)(for one baseline)
(Gan
dhi,
Win
ter,
200
6)
True =0
Feb. 14, 2008 Nu HoRIzons 2008 - Walter Winter
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Resolving the Resolving the 2323 degeneracy degeneracy
4000 km alone: Problems with 4000 km alone: Problems with degs for intermediate degs for intermediate 1313
7200 km alone: 7200 km alone: No sensitivity for small No sensitivity for small 1313
4000 km + 7200 km: 4000 km + 7200 km: Good for all Good for all 1313
(Gandhi, Winter, 2006)
Similar performanceto Gold+Silver* @ 4000km
Meloni, arXiv:0802.0086
Feb. 14, 2008 Nu HoRIzons 2008 - Walter Winter
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Solar term:Solar term:
Note thatNote that
i.e., effect increases i.e., effect increases with baseline (with baseline ( ~ L)! ~ L)!
MSW effect sensitivity: even for MSW effect sensitivity: even for 1313=0!=0!
(Winter, 2004)
5
Requirements forRequirements fornew physics searches?new physics searches?
Feb. 14, 2008 Nu HoRIzons 2008 - Walter Winter
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Non-standard neutrino interactionsNon-standard neutrino interactions Consider effective four-point interactionsConsider effective four-point interactions
This leads to a Hamiltonian for This leads to a Hamiltonian for propagation: propagation:
matter potential:matter potential:
For antineutrinos: H For antineutrinos: H H*, a H*, aCCCC -a -aCCCC
Weak constraints
Feb. 14, 2008 Nu HoRIzons 2008 - Walter Winter
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NSI with magic baselineNSI with magic baseline
Combing the two baselines Combing the two baselines reduces the impact of reduces the impact of correlations drasticallycorrelations drastically(only real (only real ee assumed!) assumed!)
Does one still need the silver Does one still need the silver channel in that case?channel in that case?
3000 km7000 km
Com
bined
arXiv:0709.1980
Close to worst case for degeneracies: CP=3/2, sin2213=0.001
+Disappearance
(Kopp, Ota, Winter, in prep)
Feb. 14, 2008 Nu HoRIzons 2008 - Walter Winter
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Correlations at magic baselineCorrelations at magic baseline Including NSI, the magic baseline is not exactly Including NSI, the magic baseline is not exactly
correlation/degeneracy-freecorrelation/degeneracy-free Example: High-E Approximation Example: High-E Approximation
aaCCCC ~ E: ~ E:
Standard term drops as 1/EStandard term drops as 1/E44, NSI-Term as 1/E, NSI-Term as 1/E33 High energies important for NSIHigh energies important for NSI!!
Feb. 14, 2008 Nu HoRIzons 2008 - Walter Winter
When does the silver channel help?When does the silver channel help? Silver channel, in principle, very sensitive to Silver channel, in principle, very sensitive to ee, ,
Fix golden baselines:Fix golden baselines:Where is the optimalWhere is the optimalsilver baseline?silver baseline?(Use Silver* (5xSG,3xBG; all hadronic (Use Silver* (5xSG,3xBG; all hadronic decay channels of the decay channels of the observed) observed)
IDS-NF MECC baseline = Golden 1
(Kopp, Ota, Winter, in prep.)
(Kitazawa, Sugiyama, Yasuda, 2006)
Feb. 14, 2008 Nu HoRIzons 2008 - Walter Winter
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Minimum muon energy?Minimum muon energy?
Higher muon energy helps; low-E NF not an optionHigher muon energy helps; low-E NF not an option Silver channel: Not relevant for IDS baseline; helps for ESilver channel: Not relevant for IDS baseline; helps for E ~ 50 GeV ~ 50 GeV
IDS
baseline High-E
version
(Kopp, Ota, Winter, in prep.)
Low
-E N
uFact?
IDS
baseline
High-E
version
Low
-E N
uFact?
~ Currentbounds
Feb. 14, 2008 Nu HoRIzons 2008 - Walter Winter
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Two baseline optimization Two baseline optimization (no silver)(no silver)
Similar to matter effects (which increase with baseline!), NSI Similar to matter effects (which increase with baseline!), NSI sensitivities want one very long baselinesensitivities want one very long baseline
Absolute sensitivity: Current limits improved by up to three orders Absolute sensitivity: Current limits improved by up to three orders of magnitude!of magnitude! (Kopp, Ota, Winter, in prep.)
37
New physics searchesNew physics searches … and the physics case for … and the physics case for detection? detection?
Two approachesTwo approaches::1)1) Have specific model, i.e., spectral Have specific model, i.e., spectral
dependencedependence2)2) Want to do general unitarity checks, i.e., no Want to do general unitarity checks, i.e., no
specific idea about spectral dependencespecific idea about spectral dependence Two solutionsTwo solutions::
1)1) Use spectral dependence with model Use spectral dependence with model parametersparametersButBut: much more statistics in P: much more statistics in Pee, P, Pthan Pthan Pee (cf., NSI example) (cf., NSI example)
2)2) Use NC or CCs NUse NC or CCs Nee+N+N+N+N;;But for NCBut for NC: Systematical uncertainties, CC : Systematical uncertainties, CC contamination limit to percent levelcontamination limit to percent levelBut for CCBut for CC: : Initial Initial : not possible because of MECC : not possible because of MECC readout rate? readout rate? Initial Initial ee: platinum CID (showers!), silver : platinum CID (showers!), silver statistics again limited to few percent!?statistics again limited to few percent!?
Is the conclusion that there is no Is the conclusion that there is no physics case for the MECC at Lphysics case for the MECC at L11??
(Barger, G
eer, Whisnant, 2004)
NC: Systematic uncertaintyin NC rate NC and CC contaminations limit
performance; limited tofew percent?
Feb. 14, 2008 Nu HoRIzons 2008 - Walter Winter
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Summary and conclusionsSummary and conclusions First generation superbeams (or reactor First generation superbeams (or reactor
experiments) may find experiments) may find 1313; however: no high-; however: no high-CL discovery of CPV, MH CL discovery of CPV, MH Need upgrades! Need upgrades!
Current IDS-NF setup uses two baselines:Current IDS-NF setup uses two baselines:Does INO match the detector requirements for Does INO match the detector requirements for the far detector?the far detector?
The physics case for the VL baseline is very The physics case for the VL baseline is very robust (a number of applications)robust (a number of applications)
Open question: Do new physics searches Open question: Do new physics searches require the silver channel? require the silver channel?
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