Phenomenology of future LBL experiments … and the context with Euro n WP6
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Transcript of Phenomenology of future LBL experiments … and the context with Euro n WP6
Phenomenology of future LBL experiments … and the context with Euro WP6
IDS-NF + Euro plenary meetingat CERNMarch 25, 2009
Walter WinterUniversität Würzburg
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Contents
Introduction to LBL phenomenology Status of
Neutrino factory Superbeams Beta beams
Current Euro/IDS-NF issues Performance indicators Benchmark setups Optimization/decision: Large versus small 13
Conclusions
This talk:Only standard
oscillationphysics
Long baseline phenomenology
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Channels of interest
Disappearance for m312, 23:
NB: We expand in
Appearance for 13, CPV, MH: Golden: e (NF/BB) or e(SB)
(e.g., De Rujula, Gavela, Hernandez, 1999; Cervera et al, 2000)
Silver: e (NF – low statistics!?)(Donini, Meloni, Migliozzi, 2002; Autiero et al, 2004)
Platinum: e (NF: maybe in low-E NF)(see e.g. ISS physics working group report)
„Discovery“: (OPERA, NF?)(e.g. Fernandez-Martinez et al, 2007; Donini et al, 2008)
Neutral currents for new physics (e.g., Barger, Geer, Whisnant, 2004; MINOS, 2008)
31 = m312 L/(4E)
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Appearance channels
(Cervera et al. 2000; Freund, Huber, Lindner, 2000; Huber, Winter, 2003; Akhmedov et al, 2004)
Antineutrinos: Magic baseline: Silver: Superbeams, Plat.:
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Degeneracies
CP asymmetry
(vacuum) suggests the use of neutrinos and antineutrinos
One discrete deg.remains in (13,)-plane(Burguet-Castell et al, 2001)Burguet-Castell et al, 2001)
Additional degeneracies: Additional degeneracies: (Barger, Marfatia, Whisnant, 2001)(Barger, Marfatia, Whisnant, 2001) Sign-degeneracy Sign-degeneracy
(Minakata, Nunokawa, 2001)(Minakata, Nunokawa, 2001) Octant degeneracy Octant degeneracy
(Fogli, Lisi, 1996)(Fogli, Lisi, 1996)
Best-fit
-beam,
-beam, anti-
Iso-probability curves
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Degeneracy resolution Matter effects (sign-
degeneracy) – long baseline, high E
Different beam energies or better energy resolution in detector
Second baseline
Good enough statistics
Other channels
Other experimentclasses
WBB FNAL-DUSEL, T2KK, NF@long L, …
Monochromatic beam, Beta beam with different isotopes, WBB, …
T2KK, magic baseline ~ 7500 km, SuperNOvA
Neutrino factory, beta beam, Mton WC
SB+BB CERN-Frejus, silver/platinum @ NF
Reactor, atmospheric, astrophysical, …
(many many authors, see e.g. ISS physics WG report)
Status of the neutrino factory
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Neutrino factory – IDS-NF
IDS-NF: Initiative from ~ 2007-2012
to present a design report, schedule, cost estimate, risk assessment for a neutrino factory
In Europe: Close connection to „Eurous“ proposal within the FP 07
In the US: „Muon collider task force“
ISS
(Geer, 1997; de Rujula, Gavela, Hernandez, 1998; Cervera et al, 2000)
Signal prop. sin2213
Contamination
Muons decay in straight sections of a storage ring
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Physics potential
Excellent 13, MH, CPV discovery reaches
About 10% full width error (3) on log10 (sin2213) for sin2213 = 0.001(Gandhi, Winter, hep-ph/0612158, Fig. 6)
About 20-60 degree full width error (3) on CP for sin2213 = 0.001 (Huber, Lindner, Winter, hep-ph/0412199, Fig. 7)
But what does that mean? Cabibbo angle-precision (C ~ 13 deg.)!
Why is that relevant? Can be another feature of nontrivial QLC models:E.g. from specific texture+QLC-type assumptions:
(: model parameter)
(Niehage, Winter, arXiv:0804.1546)
(IDS-NF, 2008)
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Low energy neutrino factory
„Low cost“ version of a neutrino factoryfor moderately large 13: E ~ 4.12 GeV
Possible through magnetized TASD with low threshold
(Geer, Mena, Pascoli, hep-ph/0701258; Bross et al, arXiv:0708.3889)
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On near detectors@IDS-NF Define near detectors including source/detector geometry:
Near detector limit: Beam smaller than detector
Far detector limit: Spectrum similar to FD
Systematics X-Section (shape) errors (30%) Flux normalization errors (2.5%) BG normalization errors (20%)
(Tang, Winter, arXiv:0903.3039)
~ND limit ~FD limit
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ND: Main results
Need two near detectors, especially for leading atmospheric parameters
Flux monitoring important for CPV (large 13)
Near detectors not relevant for 13 discovery, MH
Systematical errors cancel if two neutrino factory baselines (even without ND)
30% XSec-errors, uncorrelated among all bins
Use near detectors
(Tang, Winter, arXiv:0903.3039)
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Impact of ND+new systematics
(Tang, Winter, arXiv:0903.3039)
IDS-NF systematicstoo conservative?
CP violation, 3
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Low-E versus high-E NuFact
High-E reference: IDS-NF baseline 1.0 Low-E reference: Bross et al, arXiv:0708.3889, 1023 decays*kt,
2% systematics errors (flux norm, BGs)
(Tang, Winter, arXiv:0903.3039)
High-E NuFact one to two orders of magnitude in 13 better
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NF: Status and outlook
Characteristics: Truly international effort Green-field setup (no specific site)
High-E NuFact: Benchmark setup definedWill evolve over timeExamples: MECC, Detector masses of far detectors
Open issues:„Low cost“ alternative? Benchmark setup for that?
Euro relationship: Results shared between IDS-NF (physics) and Euro; Funding from Euro
Status of superbeams
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Beam/Superbeam setups
Characteristics: Possible projects depend on regional boundary conditions (e.g., geography, accelerator infrastructure)
Setups:MINOS
NOA (+ upgrades)WBB FNAL-DUSEL
…
Setups:CNGS
CERN SPL-Frejus…
Setups:T2K
T2HKT2KK
…
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Superbeam upgrades: Examples
Exposure L: Detector mass [Mt] xTarget power [MW] xRunning time [107s]
Bands: variation of systematical errors: 2%-5%-10%
„Typical“ CP, 3(Barger, Huber, Marfatia, Winter, hep-ph/0610301, hep-ph/0703029)
discovery
Nominal exposure
120 GeV protons
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Luminosity scalings
If 13 found by next generation: WBB and T2KK
can measure CPV, MH
NuMI requires Lumi-upgrade (ProjectX?)
Systematics impact least for WBB; best physics concept?
MH for sin2213 > 0.003
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On-axis versus off-axisExample: NuMI-like beam 100kt liquid argon
CP=-/2
CP=+/2
sin2213 CP violation Mass hierarchy
(Barger et al, hep-ph/0703029)
Constraintfrom
NuMIbeam
FNAL-DUSELWBB
Ash RiverOA,NOvA*
Off-axis technology may not be necessary if the detector is good enough, i.e., has good BG rejection and good energy resolution! WC good enough???
On axis
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L=130 km: CERN-Frejus Interesting in combination
with beta beam: Use T-inverted channels (e and e) to measure CPV
Problem: MH sensitivity, onlycomparable to T2HK
Concerns of WP6 communicated to Euro CB in Feb 2008:
„[...] It is well known that this setup has good possibilities to observe CP violation, however, due to the short baseline there will be no chance to determine the mass hierarchy. We believe that this is a very important measurement for a future neutrino facility, and will be one of the comparison criteria to be defined within this study.
We want to point out very clearly that restricting the SB study only to the CERN-Frejus setup excludes this measurement from the very beginning. […]”
European plan: CERN-MEMPHYS
2
(Campagne, Maltoni, Mezzetto, Schwetz, hep-ph/0603172)
LBL+ATM
WBB FNAL-DUSEL (average)
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SB: Status and outlook
Characteristics:Projects driven by regional interests/boundary
conditionsProjects attached to existing accelerator sites (mid
term perspective) Benchmark setups:
Partly defined (such as baselines, detectors etc)Fuzzy assumptions on proton plans, running times, …
(benchmark comparison difficult!) Relationship to Euro: Only CERN-Frejus setup
studied within Euro WP2 Concern raised by some WP6 members:
European setup maybe „dead end“?
Status of beta beams
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Original „benchmark“ setup!?
More recent key modifications: Higher (Burguet-Castell et al, hep-ph/0312068)
Different isotope pairs leading to higher neutrino energies (same )
(http://ie.lbl.gov/toi)
eFeNe 189
1810
eLiHe 63
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(CERN layout; Bouchez, Lindroos, Mezzetto, 2003; Lindroos, 2003; Mezzetto, 2003; Autin et al, 2003)
(Zucchelli, 2002)
(C. Rubbia, et al, 2006)
Key figure (any beta beam):Useful ion decays/year?
Often used “standard values”:3 1018 6He decays/year1 1018 18Ne decays/year
Typical ~ 100 – 150 (for
CERN SPS)
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Current status: A variety of ideas
“Classical” beta beams: “Medium” gamma options (150 < < ~350)
- Alternative to superbeam! Possible at SPS (+ upgrades)- Usually: Water Cherenkov detector (for Ne/He)(Burguet-Castell et al, 2003+2005; Huber et al, 2005; Donini, Fernandez-Martinez, 2006;
Coloma et al, 2007; Winter, 2008)
“High” gamma options (>> 350)- Require large accelerator (Tevatron or LHC-size)- Water Cherenkov detector or TASD or MID? (dep. on , isotopes(Burguet-Castell et al, 2003; Huber et al, 2005; Agarwalla et al, 2005, 2006, 2007, 2008, 2008;
Donini et al, 2006; Meloni et al, 2008)
Hybrids: Beta beam + superbeam
(CERN-Frejus: see before; Fermilab: see Jansson et al, 2007) “Isotope cocktail” beta beams (alternating ions)
(Donini, Fernandez-Martinez, 2006) Classical beta beam + Electron capture beam
(Bernabeu et al, 2009)
…
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Stand-alone European version?
CERN-Gran Sasso or Boulby? Example: CERN-Boulby, L=1050 km =450 (SPS upgrade), 18Ne only! Red: 1021 usef. ions x kt x yr Blue: 5x2021 usef. ions x kt x yr
99% CL
99% CL
Masshierarchy
(Meloni, Mena, Orme, Palomares-Ruiz, Pascoli, arXiv:0802.0255)
Problem: Antineutrino channel missing!(degs only partially resolved by spectrum)More later …
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BB: Status and outlook
Characteristics:Mostly European effort (so far)Partly green-field, mostly CERN-based
Benchmark setup:Often-used: SPS-based setup, sort of „benchmark“ in
the literature (e.g. for useful number of ion decays)Not up-to-date anymore wrt isotopes, , useful ion
decays etcDefine new benchmark with the necessary
requirements for WP4?
Relationship to Euro:Studied within WP4 (mostly source aspects)
Current Euro physics issues
(some thoughts)
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Performance indicators Many performance indicators used in literature What is the best way to present? Fair comparison of whole parameter space or comparison at specific
benchmark points? WP6 will have to look into this (Pilar)
Example:13 discovery
vs 13 sensitivity
(Huber, Lindner, Schwetz, Winter,
in prep.) Warning: If particular CP chosen,
any answer canbe obtained!
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Benchmark setups: Status Do we need these? At the end, for a physics comparison,
probably … Can be used to define requirements for reasonable physics
output (see, e.g., IDS-NF) Maybe: More aggressive
versus minimal versionExample: ISS Plot
Neutrino factory: Exists for high-E version Not yet for low cost version
Superbeam: Minimal version exists (apart
from specific numbers) More aggressive: Not defined
Beta beam: Minimal version exists (apart
from specific numbers) More aggressive: Not defined
(ISS, arXiv:0710.4947)
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Small 13:Optimize 13, MH, and CPV discovery reaches in 13 direction
Large 13:Optimize 13, MH, and CPV discovery reaches in (true) CP direction~ Precision!
What defines “large 13”? A Double Chooz, Day Bay, T2K, … discovery!
Optimization of exps
(3m312=0.0022 eV2
Optimization for small 13
Optimization for large 13
T2KK
Beta beam
NuF
act
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Large 13 strategy
Assume that we know 13
(Ex: Double Chooz) Minimum wish list
easy to define: 5 independent confirmation of 13 > 0 3 mass hierarchy determination for any (true) CP
3 CP violation determination for 80% (true) CP
~ Cabibbo-angle precision as a benchmark!
For any (true) 13 in 90% CL D-Chooz allowed range!(use available knowledge on 13 and risk-minimize)
What is the minimal effort (minimal cost) for that? Use resources wisely!
(arXiv:0804.4000(arXiv:0804.4000; Sim. from hep-ph/0601266; Sim. from hep-ph/0601266; 1.5 yr far det. + 1.5 yr both det.)1.5 yr far det. + 1.5 yr both det.)
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Example: Minimal beta beam
Minimal effort = One baseline only Minimal Minimal luminosity Any L (green-field!)
Example: Optimize L-for fixed Lumi: as large as 350
may not even be necessary!
(arXiv:0804.4000)(arXiv:0804.4000)
Sensitivity for entire Double Chooz allowed range!
5yr x 1.1 1018 Ne and 5yr x 2.9 1018 He useful decays
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Minimal beta beam at the CERN-SPS? ( fixed to maximum at SPS)
(arXiv:0809.3890)(arXiv:0809.3890)
(500 kt)
CERN-Boulby
CERN-LNGS
CERN-Boulby
CERN-LNGS
Conclusions:- CERN-Boulby or CERN-LNGS might be OK at current SPS if ~ 5 times more isotope decays than original benchmark (production ring?)- CERN-Frejus has too short baseline for stand-alone beta beam
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Small 13 strategy Assume that Double Chooz … do not find 13 Minimum wish list:
discovery of 13 > 0 3 mass hierarchy determination 3 CP violation determination
For as small as possible (true) 13 Two unknowns here:
For what fraction of (true) CP? One has to make a choice (e.g. max. CP violation, for 80% of all CP, for 50%, …)
How small 13 is actually good enough? Minimal effort is a matter of cost! Maybe the physics case will be defined
otherwise?
?
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Connection to high-E frontier?
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Conclusions
Current status: Neutrino factory:
Strong collaboration with IDS-NF High-E benchmark setup defined „Low cost“ version further studied
Superbeams: CERN-Frejus anticipated as benchmark Has too little MH sensitivity, even if combined with atm. data
(Issues: low energy, short baseline) Beta beams:
SPS-based benchmark often used in literature Probably not sufficient: Define more aggressive version with higher
or more isotope decays (production ring)? Next steps?
Discuss performance indicators Discuss if benchmarks needed for WP6 Connection to global perspective? …
Backup
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Long baseline experiments
Contamination
Source Production … and Detection Limitations L <E>
Beam,Super-beam
Intrinsic beam BGs,systematics
100-2,500 km
~ 0.5 – 5 GeV
Neutrino factory
Charge identification,NC BG
700-7,500 km
2-25 GeV
-beam Sourceluminosity
100-7,500 km
0.3 – 10 GeV
For leading atm. params Signal prop. sin2213
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IDS-NF baseline setup 1.0 Two decay rings E=25 GeV
5x1020 useful muon decays per baseline(both polarities!)
Two baselines:~4000 + 7500 km
Two MIND, 50kt each
Currently: MECC at shorter baseline (https://www.ids-nf.org/)(https://www.ids-nf.org/)
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Two-baseline optim. revisited
Robust optimum for ~ 4000 + 7500 km
Optimization even robust under non-standard physics(dashed curves)
(Kopp, Ota, Winter, 2008)
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Timescale for 13 discovery?
(Huber, Kopp, Lindner, Rolinec, Winter, 2006)
Assume:Decision on future experiments made after some LHC running and next-generation experiments
Two examples: ~ 2011: sin2213 > 0.04?
~ 2015: sin2213 > 0.01?
D
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Example: CPV discovery
… in (true) sin2213 and CP
Sensitive region as a
function of true 13 and CP
CP values now stacked for each 13
Read: If sin2213=10-3, we
expect a discovery for 80% of all values of CP
No CPV discovery ifCP too close to 0 or
No CPV discovery forall values of CP3
Cabibbo-angleprecision for CP
~ 85%!Fraction 80% (3)
corresponds to Cabibbo-angleprecision at 2 BENCHMARK!
Best performanceclose to max.
CPV (CP = /2 or 3/2)
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Luminosity scaling for fixed L
What is theminimal LSF x ?
(Ne,He):LSF = 1 possible(B,Li):LSF = 1 not sufficient
But: If LSF >= 5: can be lower for (B,Li) than for (Ne,He), because MH measurement dominates there (requires energy!)
(Winter, arX
iv:0804.4000)(W
inter, arXiv:0804.4000)
(100kt)(500kt)
only < 150!
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Minimal beta beam(W
inter, arXiv:0804.4000)
(Winter, arX
iv:0804.4000)