future neutrino facilities “ plan b ” of the world high energy community

Future Neutrino Facilities Plan B of the World High Energy CommunityYorikiyo NagashimaOsaka University

November 28, 2006Kanazawa University

Seminar at Kanazawa U.

International Scoping Studyof a Neutrino Factory and super-beam facilityJoint Effort by ECFA/BENE NuFact-J US Muon Collider and Neutrino Factory Collaboration UK Neutrino Factory collaboration Hosted by CCLRC/RALProposed at NuFact05. Final report to NuFact06 ( August 24, 2006) (http://www.hep.ph.ic.ac.uk/iss/)


What to do?

Investigate a best strategy for the long future of the neutrino physics considering the ongoing and near future plans of three regions.

Chairman : P.Dornan (ICL) Conveners:Physics working group : Y. Nagashima (Osaka)Detector working group: A.Blondel (CERN)Accelerator working group: M.Zisman (LBL)


Where do we go from here ?Two directions beyond SM, toward UnificationEW symmetry breaking, HIGGS, GUT, SUSY, ED LHC, ILC Clear theoretical guide exists: Top down approachDiscovery !Flavor ProblemOrigin of generations, Mass Hierarchy Super B, nFactoryNo clear theory exists. Only experimental observations: Bottom Up ApproachPrecision and surprise !


Many of these questions usually reside in GUT scale and beyond,


A given GUT model usually has generic predictions for low energy observables.Studying ns gives considerable insight into phenomena which otherwise would be inaccessible.Colliders can not probe this kind of physics, since any effects in scattering amplitudes are suppressed by MGUT, ~O(10-10) at LHC !


Key measurements The most sensitive low energy observables areMajorana mass 0nbbAbsolute mn Katrin, CosmologyOscillation measurements can address following questions.How large is q13 ? Leptonic CP violation ? n mass hierarchy ? Is q23 maximal ?Unitarity test and/or more than 3 ns? Test of Q-L complementarity: ex.Test of Sum rules: ex.Model prediction


The neutrino mixing matrix: 3 angles and a Dirac phase + 2 Majorana phases?


Unknown or poorly known 13 , CP phase , sign of Dm213From now on, assume standard 3 flavor oscillation.Use above 3 indicators forOptimization of future neutrino facilities.


Neutrino Oscillation Appearance Probability(q13) . .CP .sin22q13

Yellow; Numi, 45mradEn of most SB and BB peaks at ~1GeVNeutrino Factory


LBL expts. operate at atmospheric n distanceNote: The functions scale as L/EEarth diameter


To resolve mass hierarchy, a long baseline(>1000km) is neededMagic Baseline


3 types of accelerator neutrino facilitiesSuper BeamConventional: use p mn : nm Mega watt class proton acceleratorContamination of ne in beamBeta BeamProduce beta active isotope A* Aene ne And accelerate (use SPS or LHC)Q-value low collimated beam, small BKGNeutrino FactoryUse m from p decay, cool, accelerate, store and let m decay : ne, nm Clean, intense, high energy (10-30GeV), all channels availableConsidered as an ultimate neutrino facilityNeeds R&D, Cost?Ongoing experiments are all of SB type


Accelerator n ExperimentsConfirm atm. Osci.Find q13Measure CP, solve MHUltimate facility

PhaseJapanU SEurope1. NowK2K (done) (250 km)MiniBooNEMINOS (735 km)OPERA, ICARUS (730 km)2. Next 5 yrsT2K (2009~)(295 km)NOnA (2013~)(810 km)3. Next 10 yrs ? T2KII (4MW)T2HK (SKHK)Or T2KK (~1200km)NOnA IIw/PD and 2nd OADetectorWBB with very long baseline ( >2000km)MEMPHYS(130km)(SPL+ b Beam, g=150)4. After that n Factory ?(En=20-50 GeV, 4000+7500km) b Beam ? (g=350,730km)


Super Beam (< 1MW 4MW) T2K, NOvA, SPLFind non-zero q13 down to sin22q13 ~ 10-2Expect to measure Dm213: 23% 10% MINOS 2% T2K, NOvASuper Beam Phase II (Detector Upgrade) T2HK, NOvAIIsin22q13 ~10-3 mass-hierarchy up to sin22q13 ~ 10-2 for all values of d NOvA II, T2KKSearch for CP violationDm132 1%

Note: Reactor is very competitive in search of q13


Adapted from Lindner et al.,Hep-ph/0403068, 0503101~2013Future


Correlation and Degeneracy


Total of 8-fold degeneracy q13 - d (intrinsic) ambiguity. Mass hierarchy two-fold (sign) degeneracy: |Dm231|=|-Dm231| q23 (octant) degeneracy: sin22q23= sin22(p/2-q)23Sign degeneracy


2 different L/E or a wide band beam(b) Same L/E 2 different channelsSolving the degeneracy Synergy of independent experiments


Degeneracy free, clean experimentShort baseline reactor experiments: 2nd term small for sin22q13 >> 10-3 !

(see e.g. Akhmedov et al., hep-ph/0402175)No dCP, No mass hierarchy!Note: D31=Dm231L/4EDChooz


Reactor data are more effective than anti-neutrinosNote: Reactor II : sin22q13=0.01M.Lindner; hep-ph/0503101


NOvA alone suffers from sign degeneracy.Adding reactor data solves the problem.


Near Future : Next 5 yrs. (Super Beam I)


Detectors for SB and BB are similar.Type 1: Water cherenkov counter a la SK (=50 kt) Upgrade x10 volume : ~Megaton Hyper Kamiokande, UNO, MEMPHYSEn < 1GeVQuasi Elastic eventsLarge volume


Detector for SB, Type 2, TASD: Totally Active Scintillator Detctor a la NOvAEn ~1-5GeVModerate Volume

Proposed NOvA Detector30 ktons of liquid scintilltor15.7m x 15.7m x 132m1984 layers635,136 cells, each 3.8x6.0x1570 cm3 Readout by WLS+1 APD ~20 p.e. expected

Readout


T2K can probesin22q13~0.01 .And also has some sensitivity to CP


NOvA compared withT2K


95% CL Resolution of the Mass OrderingT2KNOvAs strength is in mass hierarchy.


Near Future / next 10 yrs P.Huber et al., hep-ph/0403068 Dm2=2.0x10-3eV2Super Beam: Phase II1 improvementover ongoing experiments


NOvAs effort to compete with T2HK


+++++NOnA95% CL Resolution of the Mass HierarchyPossible Reach in 2010-2020Here, NOvAs long baseline is an advantage.2nd detector


T2KKT2HKs solution to compete with NOvA IISplit T2HK detector into two and place one in Korea Long baseline helps to resolve degeneracy at Kamioka.T2KK reach comparable or better than NOvA and T2HK combined T.Kajita, K.NakamuraP.Oddone


By taking to Korea, the ability to solve degeneracies enhanced .


T2KK: enhanced abilities Note; the difference in systematics(3s, Dm312=0.0025 eV2)PRELIMINARY(Barger, Huber, Marfatia, Winter, in preparation)


Expected sensitivity23T2K-II(Kamioka)Kamioka+KoreaSensitivity to CP(sind0)Sensitivity to mass hierarchyNeutrino + anti-neutrino runs = 8 yearshep-ph/0504026Conclusion: T2K~NOvA, T2HK~NOvA II except mass hierarchyT2KK~NOvA II in all aspects


US: Further effort :NOvA comparable with T2K in q13, CP NOvA II outperforms T2HK in mass hierarchy, but T2KK can compete with NOvA II. Their solution? Wide Band Beam w/very long baseline .


If WBB and the UNO water cherenkov detector can perform as claimedit is as good as any other Super Beam experiments.However, No direct En information: En has to be reconstructed Use Quasi Elastic EventsRejection of NC BKG is crucial.Liq. Ar. is a solution, but a large Liq. Ar. Det. ?Under investigation


T2KK is good at sin22q13 and CPV discoveryWBB is better at mass hierarchy.Comparison of SB performances I


Why is T2KK good at q13 and CPV ?Large mass counts !Comparison of SB performances II


The MEMPHYS Project: SPL (Super Proton Linac) and Beta-Beam : From CERN to FREJUSSPL @ CERN: On axis beam2.2GeV, 50Hz, 2.3x1014p/pulse 4MWNeutrino beam energy: ~0.3 GeVFuture possibility: CERN to Gran Sasso in Italy (730km) In the meantime, Europeans are thinking ahead. .


CERN Super-beam: 13 and CP discovery reach. .T2HK (slightly) out-performs SPLT2HK closer to being systematically limited (effect of going from 2% systematic errors to 5%) .


Advantage of b BeamFlux and E-spectrum well-kown 1%Pure ne beam, LE in ion-CMStrong collimation good at LBLNear/Far spectrum very similar Low BKG Adjustable E Experiments @diff. E Synergy w/SPL Can run both at SB mode (nm ne) and BB mode (ne nm) Useful to resolve degeneracy Suitable for T, CPT exp.


J-E. Campagne et al hep-ph/0603172 SPL+BB1 synergySPL alone cannot outperform T2HK, but the combination of SPL and BB1 does.


Neutrino FactoryProvides clean intense ne nm channel (Golden) and ne nt channel (Silver) and nm ne channel (Platinum) And disappearance channels nm nm and ne neNF (golden)+SB combined solves degeneracies down to sin22q13 ~ 10-5Considered as the ultimate neutrino facilityThe question is cost consideration (1500M$+400M$*E/20 in Study II) Long Future/ next 20 years ?


Neutrino Factory:Concept:Produce intense ps.Phase rotate and cool.Accelerate and store.Up to 1021 decay ms /yr.NF design as of 2006


NF: baseline detector as of 2006Baseline: 50 kt Iron detector with Em=50GeV 1021 decays/yr; exposure 5 plus 5 years


ISS Study 1 : Optimization of Golden channel (ne nm)Baseline: 50 kt Iron detector with Em=50GeV 1021 decays/yr; exposure 5 plus 5 years

Improved detector: Golden*

Improved: Threshold Resolution

Baseline: Threshold Resolution

Similar to NOvA detector


NF: with improved (Golden*) detector Better detector threshold makes L=2000-4000 km very efficient q13-baseline for exclusion limit One detector Golden*Huber, Lindner, Rolinec, Winter hep-ph/0606119


ISS study 2 : additional channels in NF:Emulsion cloud chamber: SilverOPERA-like performance ; 5 kTonEmulsion cloud chamber : Silver*10 kT + 5 times efficiencyLiquid argon detector: Platinum15 kTon; Eres ~ 0.15% E ; charge ID to 7.5 GeV0.2 signal efficiency, 0.01 charge confusionGolden* with electron CID : Platinum*50 kt charge ID up to 50 GeV

Note: Siver* and Platinum* very optimistic spec.


supermoduleTarget TrackersPb/Em. targetECC emulsion analysis:Vertex, decay kink e/g ID, multiple scattering, kinematicsExtract selected brick Pb/Em. brickPb1 mmBasic cellEmulsion trigger and locate the neutrino interactions muon identification and momentum/charge measurementElectronic detectors:Brick finding, muon ID, charge and pLink to muon ID,Candidate eventSpectrometerp/p < 20%Silver Channel


Platinum channel:Useful to resolve degeneracy However, Liq. Ar. Detector suffer from CID upper limit. Currently Charge ID < 7.5 GeVImproves performance at large sin22q13 (0.1-0.01)CID upper limit OK, hereHigh efficiency compared to scintillators x 2-3


At magic baseline (~7500km)

Resolves degeneracy problem.But, no sensitivity to CP or sign(Dm213)Addition of Golden(*) at magic baselineCombination of 1 detctor at L=7500* solves degeneracy and another at 3000km measure CP and sign(Dm213) looks best **.Note: * Indian INO is located at MB from CERN. http://www.imsc.res.in/~ino/ ** do not consider other useful channels.


NF: alternative way to resolve degeneracyAddition of either silver or platinum channel solves the degeneracy problem. However, detector feasibility is uncertain.Note 1 : Improved detector (Golden*) alone performs just as well.Note 2 : The optimal solution is to add 2nd detector at MB.


ISS Study III : NF Optimization Potential . .(1) Golden50 kT, MID, L = 4000 kmE = 50 GeV(2)=(1)+(Golden)MB(3)=(2), but Golden ->Golden* and Em=20GeV(4)=(3)+Platinum*Current proposalGolden detector at 4000km and at MBEm : 20-50GeVUpgrade later to Golden*5% error2% errorP.Huber et al., hep ph/0606119


ISS study on NF: SummaryPast NF optimized for cleanest wrong sign muon HE n sit at tails of 1st maximum suffer from degeneracyImproved detector sensitive to 1st maximum help to solve degeneracyEstablished Doable En range 20-50GeV (used to be 50 GeV or above) NF competitive with SB at large sin22q13=0.1-0.01Performance of additional channelsDegeneracy can be solved by addition of MB, or improved detector (golden*), or addition of silver* or platinum*.Silver or Platinum are not enough, however Silver* and Platinum* need extensive R&DCurrent choice of detector configurationGolden at 4000km and MB (7500km) then upgrade to Golden*


Performance comparison of various facilities.(On equal footings)Experimental conditions.The bands in figures indicateSystematics: SPL and T2HK from 5% to 2% WBB as proposalBeta beam: from BB1: g=100, 500kt water C (130km) to BB2: g=350, 500kt water C (730km)Neutrino Factory: from Golden (4000km), E = 50 GeV to Golden* (4000 km)+ Golden* (7500 km), E = 20 GeV


13 Sensitivity Mass hierarchy .PreliminaryPreliminaryNF can outperform SB and BB for sin22q13 < 0.001ISS Study IV : Comparison


Comparison: CP violation .PreliminaryBB2 does best at sin22 q13 > 10-2.5 However, SB may come earlier.For sin22 q13 < 10-3, NF is unique.


Which option for large q13 /or for small q13?Superbeam? (loweset possible effort).May suffer from systematics: more R&Db-beams + SPL are more sensitive for sin2 2q13 > 0.01.below this value NF is more sensitive.Decision point for small sin22q13 (= 0.01) for NF ?Depends on what optimized for : MH or CPV. Take two ?(from Huber et al, hep-ph/0601266)Decision point ?


Evaluation of the facilities: SummarySB can be sensitive down to sin22q13~10-3T2HK is competitive with any other SB facilities (NOvA, SPL, or WBB ) except on mass hierarchy. T2KK solves this problem and improves CP sensitivity considerably .BB1 is marginally better than SB, but has no sensitivity on mass hierarchy.BB2 extends q13 reach considerably and is the best performer in CP at large q13(10-2.5)BB can be competitive with SB/NF, if it can be built easily on existing facility like SPS.NF has no match for q13 < 10-3, can reach 10-5 and competes favorably at large q13 .Decision point for NF, when sin22q13 < 0.01 ?But, what is the most likely value of sin22q13 ? If sin2q13

Identifying the correct theory:Precise knowledge of neutrino mixing parameters can discriminate:


What to do for future ?IDS (International Design Study ) : starting soonTarget: CDR by 2012 : proposal as a post LHC or ILC parallel project ?

For Japan, the path seems already fixed.Plan B is running already ahead of Plan A !Neutrino projects and possibly Super B. So, cross fingers for early discovery of sin22q13 and go to T2HK or T2KK to verify CP violation. Challenge: reduce systematics < 2% ??


P.Huber et al., hep-ph/0412199 Past studies showed that NF always outperforms SBexcept for very large values of sin22q13 > 0.01 (large uncertainties from matter effect) Resultant attitude: NF is good only for small q13 , wait for SB to discover q13. So, at the ISS, we asked ourselves Is a NF needed if sin22q13 is large ? What is the minimum NF energy that will deliver the physics ? (cost issue)


ISS Study 1 on NF: Golden channel optimisationMagic baseline (7500 km) is a good degeneracy solverStored muon energy > 20 GeVsin2213: 5 sensitivityHuber, Lindner, Rolinec, Winter hep-ph/0606119


NF: Golden channel optimisationBaseline: 3000 5000 km is good for CPV.Stored-muon energy > 30 GeVCP violation: 3 sensitivity


NF: Golden channel optimisationBaseline: the longer, the better, optimum ~7500 kmStored muon energy 20 50 GeVMass hierarchy: 3 sensitivity


What is the lowest energy to produce physics?Huber, Lindner, Rolinec, Winter hep-ph/0606119 Em=20-50 GeV OKOptimal appearance Em=20GeV, L=1000 km

Em > 30 GeV preferred


NF optimization potential 1.Optimized NF : Excellent q13 reach for both MH and CPV3s(Huber, Lindner, Rolinec, Winter, hep-ph/0606119; b-beam: Burguet-Castell et al, hep-ph/0503021)


Ability to observe non-zero q13 vs timeFermilab Proton driver study reporthttp://protondriver.fnal.gov/Here time scale is fuzzyTimeline of sin22q13 as viewed by Fermilab


Why are Neutrinos Particularly Interesting?Neutrinos are the only fundamental building blocks which can be their own antiparticles (Majorana particles)Neutrinos could be responsible for the matter/antimatter asymmetry of the universe (Leptogenesis) Requires CP violationSuper partner of the neutrino could be responsible for InflationSee-saw mechanism gives a natural explanation of both:Small neutrino massLarge lepton mixing anglesso neutrino probes physics at very high mass scalesDetailed understanding of properties of neutrino is required to understand the physics of flavour

On-axis, wide-band beam: two options: (10 yr)BNL UNO at Henderson/HomestakeProton beam energy: 24 GeVNeutrino beam energy: 0 6 GeVBaseline: 2500 kmFNAL UNO at Henderson/HomestakeProton beam energy: 120 GeVNeutrino beam energy: 0 10 GeVBaseline: 1250 kmAdvantages:See 1st & 2nd max., so good degeneracy resolutionChallenge:Needs good Eres for recons. & bg suppression

MEMPHYS: Main results of the preliminary studyBest site (rock quality) in the middle of the mountain, at a depth of 4800 mwe Cylindrical shafts feasible: = 65 m and a height h = 80 m ( 250 000 m3) 215 000 tons of water (4 times SK) - 4 m from outside for veto and fiducial cut 146 000 tons fiducial target3 modules would give 440 kilotons Fid. (like UNO) BASELINEestimated excavation cost 80 M X Nb of shaftsthis number should be >~ doubled for photo-detectors, electronics and other infrastructure (--> >~500 M for three shafts = 440 kton fiducial) -- >~G for a megaton --

Produce beta active isotopesStore 18Ne, 6He, accelerate and let them decay to produce pure e and e beamsHe 2.9 1018 decays per year, max. g=150 @SPSNe 1.1 1018 decays per year, max. g=250 @SPSTwo beta-beam options considered:BB1: g=100, L=130km (CERN to Frejus)BB2: g=350, L=730km (CERN to Gran Sasso)Note: Tevatron and LHC can give g~350 , g

future neutrino facilities “ plan b ” of the world high energy community

Documents

kanazawa universityseminar

neutrino physics

n mass hierarchy

long future

mass hierarchy super

p decay

gut scale

future plans