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

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(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)