Physics applications of Physics applications of “very long” “very long” neutrino factory neutrino factory baselines baselines PHENO 2005 PHENO 2005 May 3, 2005 May 3, 2005 Walter Winter Walter Winter Institute for Advanced Institute for Advanced Study, Princeton Study, Princeton
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Physics applications of “very long” neutrino factory baselines
Physics applications of “very long” neutrino factory baselines. PHENO 2005 May 3, 2005 Walter Winter Institute for Advanced Study, Princeton. Contents. Introduction What are “very long” baselines? Applications of very long baselines Detector sites for very long baselines Summary. - PowerPoint PPT Presentation
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Physics applications of “very long” Physics applications of “very long” neutrino factory baselinesneutrino factory baselines
PHENO 2005PHENO 2005May 3, 2005May 3, 2005
Walter WinterWalter Winter
Institute for Advanced Study, PrincetonInstitute for Advanced Study, Princeton
May 3, 2005 PHENO 2005 - Walter Winter 2
ContentsContents
IntroductionIntroduction What are “very long” baselines?What are “very long” baselines? Applications of very long baselinesApplications of very long baselines Detector sites for very long baselinesDetector sites for very long baselines SummarySummary
May 3, 2005 PHENO 2005 - Walter Winter 3
Picture of three-flavor oscillationsPicture of three-flavor oscillations
Magnitude of Magnitude of 1313 is key to is key to
““subleading” effects: subleading” effects: Mass hierarchy Mass hierarchy
• EE = 50 GeV, L = 3,000 km (standard configuration) = 50 GeV, L = 3,000 km (standard configuration)• Running time: 4 years in each polarity = 8 yearsRunning time: 4 years in each polarity = 8 years• Detector: 50 kt magnetized iron calorimeterDetector: 50 kt magnetized iron calorimeter• 5.3 105.3 102020 useful muon decays/ year (4 MW target power) useful muon decays/ year (4 MW target power)• 10% prec. on solar params, 5% matter density uncertainty10% prec. on solar params, 5% matter density uncertainty• Atmospheric parameters best measured by disapp. channelAtmospheric parameters best measured by disapp. channel
Phenomenology of VL baselines (1)Phenomenology of VL baselines (1)
(Factor 1)2
(Factor 2)2
(Factor 1)(Factor 2)Prop. To L2; compensated
by flux prop. to 1/L2
May 3, 2005 PHENO 2005 - Walter Winter 9
Factor 1:Factor 1: Depends on energy; Depends on energy; can be matter enhanced can be matter enhanced for long L; for long L; however: the longer L, however: the longer L, the stronger change off the stronger change off the resonancethe resonance
Factor 2:Factor 2:Always suppressed for Always suppressed for longer L; longer L; zero at “magic zero at “magic baseline” (indep. of E, baseline” (indep. of E, osc. Params)osc. Params)
Phenomenology of VL baselines (2)Phenomenology of VL baselines (2)
(m312 = 0.0025, =4.3 g/cm3, normal hierarchy)
Factor 2 always suppresses CP and solar terms for very Factor 2 always suppresses CP and solar terms for very long baselines; note that these terms include 1/Llong baselines; note that these terms include 1/L22-dep.!-dep.!
Factor 2=0Factor 2=0 independent independent of E, osc. Paramsof E, osc. Params
Purpose: Purpose: “Clean” measurement of “Clean” measurement of 1313 and mass hierarchy and mass hierarchy
Drawback: No Drawback: No CPCP measurement at magic baseline measurement at magic baseline combine with shorter baseline, such as L=3 000 kmcombine with shorter baseline, such as L=3 000 km
1313-range: 10-range: 10-4-4 < sin < sin22221313 < 10 < 10-2-2,,where most problems with degeneracies are presentwhere most problems with degeneracies are present
May 3, 2005 PHENO 2005 - Walter Winter 11
Unstable: Disappears for different parameter
values
Magic baseline: Magic baseline: 1313 sensitivity sensitivityUse two-baseline space (LUse two-baseline space (L11,L,L22) with (25kt, 25kt) and compute ) with (25kt, 25kt) and compute 1313
sensitivity including correlations and degeneracies:sensitivity including correlations and degeneracies:
CP coverage and “real synergies”CP coverage and “real synergies”
3 000 km + 7 500 km3 000 km + 7 500 kmversus all detector mass at versus all detector mass at 3 000 km (2L)3 000 km (2L)
Magic baseline allows a Magic baseline allows a risk-minimized risk-minimized measurement (unknown measurement (unknown ))
““Staged neutrino factory”: Staged neutrino factory”: Option to add magic Option to add magic baseline later if in “bad” baseline later if in “bad” quadrants?quadrants?
Range of all fit values which fit a chosen simulated value of CP
Any “extra” gain beyond a simple addition of statistics
One baseline enoughOne baseline enough Two baselines necessaryTwo baselines necessary(Huber, Lindner, Winter, hep-ph/0412199)
Appl. 2: Matter effect sensitivity for Appl. 2: Matter effect sensitivity for 1313=0=0 Idea: For Idea: For 1313=0 only =0 only
“solar term” survives. “solar term” survives. Factor 2 Factor 2 is suppressed in is suppressed in matter vs. vacuum :matter vs. vacuum :
Purpose: Verify MSW effect Purpose: Verify MSW effect at high CL even for at high CL even for 1313=0=0
Drawback: No mass hierarchy measurement (this term)Drawback: No mass hierarchy measurement (this term) 1313-range: Interesting for sin-range: Interesting for sin22221313 < 10 < 10-3-3
Note: No 1/LNote: No 1/L22 suppression of solar term in vacuum! suppression of solar term in vacuum!
Depending on sinDepending on sin22221313, L=3 , L=3
000 km might be sufficient000 km might be sufficient For sinFor sin22221313 << << 22 ~ 10 ~ 10-3-3::
Independent of sinIndependent of sin22221313, ,
even works foreven works for sinsin22221313=0:=0:
L > 6 000 km required!L > 6 000 km required!
(Winter, hep-ph/0411309, to appear in PLB)
No sensitivity here
(CP=0)
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MSW effect vs. mass hierarchyMSW effect vs. mass hierarchy Both qualitatively similar Both qualitatively similar
for large for large 1313,, but:but:matter effect sens. hardermatter effect sens. harder(Difference vacuum-matter < (Difference vacuum-matter < difference normal-inverted)difference normal-inverted)
Small Small 13: 13: No mass No mass hierarchy sensitivity hierarchy sensitivity whatsoever whatsoever (includes disappearance (includes disappearance channel!)channel!)
Some dependence onSome dependence onCPCP, , but L > 6 000 km safebut L > 6 000 km safe
(5dashed curve: no correlations)
(Winter, hep-ph/0411309, to appear in PLB)
May 3, 2005 PHENO 2005 - Walter Winter 17
Application 3: Application 3: Measurement of the Earth’s core densityMeasurement of the Earth’s core density
Idea:Idea:Factor 1Factor 1 does not drop prop. does not drop prop. 1/L1/L22 close to resonance close to resonance
But: The longer L, the sharper But: The longer L, the sharper the change off the resonancethe change off the resonance Very sensitive to matter Very sensitive to matter density especially for large Ldensity especially for large L
Purpose: Purpose: Measure the absolute density of the Earth’s coreMeasure the absolute density of the Earth’s core
Drawbacks: Not possible to measure Drawbacks: Not possible to measure CPCP; ; “vertical” decay tunnel sophisticated“vertical” decay tunnel sophisticated
Core density measurement: Core density measurement: PrinciplesPrinciples Most Most directdirect information on the matter density from Earth’s mass and information on the matter density from Earth’s mass and
rotational inertia, but:rotational inertia, but:
Least sensitive to the innermost partsLeast sensitive to the innermost parts Seismic waves: s-waves mainly Seismic waves: s-waves mainly
reflected on core boundariesreflected on core boundaries Least information on inner coreLeast information on inner core No “direct” matter density measurement; No “direct” matter density measurement;
depends on EOSdepends on EOS No “absolute” densities: mainly sensitive No “absolute” densities: mainly sensitive
to density jumpsto density jumps Neutrinos: Measure Baseline-Neutrinos: Measure Baseline-
averaged density:averaged density:
Equal contribution of innermost parts. Measure least known innermost density!Equal contribution of innermost parts. Measure least known innermost density!
May 3, 2005 PHENO 2005 - Walter Winter 19
Core density measurement: ResultsCore density measurement: Results First: consider “ideal” First: consider “ideal”
geographical setup:geographical setup:Measure Measure ICIC (inner core) with (inner core) with L=2 RL=2 REE
Combine with L=3000 km to Combine with L=3000 km to measure oscillation parametersmeasure oscillation parameters
Key question: Key question: Does this Does this measurement survive the measurement survive the correlations with the unknown correlations with the unknown oscillation parameters?oscillation parameters?
For sinFor sin22221313 > 0.01 a precision at > 0.01 a precision at the per cent level is realistic the per cent level is realistic
For 0.001 < sinFor 0.001 < sin22221313 < 0.01: < 0.01:Correlations much worse Correlations much worse without 3000 km baselinewithout 3000 km baseline
(Winter, hep-ph/0502097)
(1, 2, 3, CP=0, Dashed: no correlations)
May 3, 2005 PHENO 2005 - Walter Winter 20
Density measurement: GeographyDensity measurement: GeographySomething else than water in “core shadow”?
Inner core shadow
Outer core
shadow
May 3, 2005 PHENO 2005 - Walter Winter 21
““Realistic geography”Realistic geography”… … and sinand sin22221313=0.01. Examples for =0.01. Examples for ICIC::
There are potential detector locations!There are potential detector locations! Per cent level precision not unrealisticPer cent level precision not unrealistic
Verify Earth Verify Earth matter effects at matter effects at high CLhigh CL
LL L>10 665 kmL>10 665 km
(outer core)(outer core)
L ~ 7 500 kmL ~ 7 500 km L > 6 000 kmL > 6 000 km
Major challenge: Decay ring/decay tunnel slopeMajor challenge: Decay ring/decay tunnel slope Open question: Simultaneous or subsequent operation of VL Open question: Simultaneous or subsequent operation of VL
baseline? Feasiblity study for storage ring configurations needed!baseline? Feasiblity study for storage ring configurations needed!