Neutrinos from Stored Muons n STORM

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Neutrinos from Stored Muons n STORM. n physics with a μ storage ring. Outline. Introduction & Physics motivation Current facility design status International context Moving forward and Conclusions. Introduction. - PowerPoint PPT Presentation

Transcript of Neutrinos from Stored Muons n STORM

MuCool Status and Plans

Neutrinos from Stored MuonsnSTORMn physics with a storage ring

OutlineIntroduction & Physics motivationCurrent facility design statusInternational contextMoving forward and Conclusions2Alan Bross EPSHEP2013 July 20, 2013 IntroductionFor over 30 years physicists have been talking about doing n experiments with ns from m decay

Flavor content fully knownOn the order of rare decay modes (10-4)Near Absolute Flux Determination is possible in a storage ringBeam current, polarization, beam divergence monitor, mp spectrometerOverall, there is tremendous control of systematic uncertainties with a well designed systemInitially the motivation was high-energy n interaction physics.

BUT, so far no experiment has ever been done!


Alan Bross EPSHEP2013 July 20, 2013 4Alan Bross EPSHEP2013 July 20, 2013 Status of the Neutrino Factory design: IDS-NFThisis the simplestimplementationof the NFAnd DOES NOTRequire the Development ofANYNew TechnologyThis is what we want to do near-term:Neutrinos from STORed Muons, nSTORM

3.8 GeV/cIt is a near-term facilityBecause, technically, we can do it nowThree Scientific Pillars or themesAddresses the SBL, large dm2 n-oscillation regimeProvides a beam for precision n interaction physicsAccelerator & Detector technology test bedPotential for intense low energy muon beamProvides for m decay ring R&D (instrumentation) & technology demonstration platformProvides a n Detector Test Facility

nuSTORM is an affordable m-based n beam First Step5Alan Bross EPSHEP2013 July 20, 2013 Physics motivation &Theoretical Considerations

Beyond the nSM

Short-baseline n oscillation studiesSterile neutrinos arise naturally in many extensions of the Standard Model.GUT modelsSeesaw mechanism for n massDark sectorUsually heavy, but light not ruled out.Experimental hintsLSNDMiniBooNEGaReactor anomaly7Alan Bross EPSHEP2013 July 20, 2013 Kopp, Machado, Maltoni & Schwetz: arXiv:1303.3011".3+1

Appearance & disappearance

8Alan Bross EPSHEP2013 July 20, 2013

Subsets of appearance and disappearance data are found to be consistent,and it is only when they are combined and when, in addition, exclusion limits onnm disappearance are included, that tension appears.n Interaction Physicsn Interaction PhysicsA partial samplingne and ne-bar x-section measurementsA UNIQUE contribution from nuSTORM Essentially no existing datap0 production in n interactionsCoherent and quasi-exclusive single p0 production Charged p & K productionCoherent and quasi-exclusive single p+ production Multi-nucleon final statesn-e scatteringn-Nucleon neutral current scatteringMeasurement of NC to CC ratioCharged and neutral current processesMeasurement of ne induced resonance productionNuclear effectsSemi-exclusive & exclusive processesMeasurement of Ks0, L & L-bar productionNew physics & exotic processesTest of nm - ne universalityHeavy neV-scale pseudo-scalar penetrating particles

10Alan Bross EPSHEP2013 July 20, 2013 Over 60 topics (thesis)accessible at nuSTORMThe Facility

Baseline~ 100 kW Target Station (designed for 400kW)Assume 60-120 GeV protonCarbon targetInconel Horn collection after targetCollection/transport channelStochastic injection of pDecay ringLarge aperture FODOAlso considering RFFAGInstrumentationBCTs, mag-Spec in arc, polarimeter12Alan Bross EPSHEP2013 July 20, 2013 3.8 GeV/cm-base n beam:Oscillation channels13

8 out of 12 channels potentially accessibleAlan Bross EPSHEP2013 July 20, 2013

13p Production, Capture & Transport14Alan Bross EPSHEP2013 July 20, 2013 In momentum range4.5 < 5.0 < 5.5obtain 0.09 p/POTwithin decay ring acceptance.With 120 GeV p & NuMI-style horn 1Carbon targetTarget/capture optimization ongoing

Sergei StriganovAo LiuFermilab

p Transport & Decay ring15Alan Bross EPSHEP2013 July 20, 2013

Injection schemes are on an injection orbitseparated by chicanes are in ring circulating orbitlower p ~3.8 GeV/c~30cm separation between16Alan Bross EPSHEP2013 July 20, 2013 Concept works for FODO latticeNow detailed by Ao LiuBeam Combination Section (BCS)

David Neuffers originalconcept from 1980BCS

17Alan Bross EPSHEP2013 July 20, 2013 ms at end of first straight

18Alan Bross EPSHEP2013 July 20, 2013 Ao LiuFermilab8 X 10-3 muons/POT (3.8 10%) GeV/c at end of first straightInjecting 6 GeV/c p19Alan Bross EPSHEP2013 July 20, 2013

m momentum distributionat end of first straightx: 5 GeV/c injectionx: 6 GeV/c injectionnuSTORMs Physics performanceAssumptionsNm = (POT) X (p/POT) X m/p X Adynamic X W1021 POT @ 120 GeV integrated exposure0.1 p/POTMuons/POT at end of first straight (8 X 10-3)=(p/POT) X (m/p) within the 3.8 10% GeV/c momentum acceptanceAdynamic = 0.6 (FODO)Fraction of muons surviving 100 turnsW = Straight/circumference ratio (0.39) (FODO)This yields 1.9 X 1018 useful m decays21Alan Bross EPSHEP2013 July 20, 2013 En spectra (m+ stored)

22Alan Bross EPSHEP2013 July 20, 2013


Event rates/100Tat ND hall 50m from straight with m+ storedfor1021 POT exposureSBL oscillation searchesAppearanceThe Golden channel Experimental Layout

24Alan Bross EPSHEP2013 July 20, 2013 Must reject thewrong sign m withgreat efficiencyAppearanceChannel:ne nmGolden Channel Why nm neAppearance Ch.not possible185~ 1900 mChris TunnellOxford** Now at NIKHEFSuperBIND25Alan Bross EPSHEP2013 July 20, 2013

Event reconstruction efficiency & Backgrounds26Alan Bross EPSHEP2013 July 20, 2013

Boosted Decision Tree (BDT) analysisSignal efficiencyBackground efficiencyne nm appearanceCPT invariant channel to LSND/MiniBooNE27Alan Bross EPSHEP2013 July 20, 2013 S:B = 12:1

AppearanceExclusion contours

28Alan Bross EPSHEP2013 July 20, 2013 Accelerator R&DLooking ForwardLooking Forward: Beyond n physics

30Alan Bross EPSHEP2013 July 20, 2013 C. Rubbia, Neutrino Telescopes 2013nuSTORMSetting the stage for the next step31Alan Bross EPSHEP2013 July 20, 2013 Only ~50% of ps decay in straightNeed p absorber

Low Energy m beam

32Alan Bross EPSHEP2013 July 20, 2013 After 3.48m Fe, we have 1010 m/pulse in 100 < P(MeV/c) < 300At end of straight wehave a lot of ps, but also a lot of ms with4.5 < P(GeV/c) < 5.5

Project SitingSiting Plan34Alan Bross EPSHEP2013 July 20, 2013

Steve DixonFermilab FESS

Site schematic35Alan Bross EPSHEP2013 July 20, 2013 226 mNear detector hall

36Alan Bross EPSHEP2013 July 20, 2013 Far Detector HallD0 Assembly Building

37Alan Bross EPSHEP2013 July 20, 2013 Implementation, at CERN:Principal issue:SPS spill is 10 s:Implies bend for proton or pion beamOr development of fast extraction

Two options:North Area implementation:NA-to-WA implementation:Advantage is proton/pion bend not required;Longer baseline must be tuned to larger muon energy (possibly an advantage too)

Moving ForwardnuSTORM Twin-Track ApproachDevelop International support at the Laboratory level for the conceptAlready Bottom-up (grass roots), now add Top-downLOI to Fermilab (June 2012), EOI to CERN (April 2013), Proposal to Fermilab (June 2013)Has produced significant increase in the size of the collaborationFrom 38 at time of Fermilab LOI to 110 now (single collaboration)EOI to CERN presented at June SPSC meeting. Requested support to:Investigate in detail how nuSTORM could be implemented at CERN; andDevelop options for decisive European contributions to the nuSTORM facility and experimental program wherever the facility is sited.Full Proposal submitted to Fermilab PAC in JuneRequested Stage I approvalIt defines a roughly two-year program which culminates in the delivery of a Technical Design Report.40Alan Bross EPSHEP2013 July 20, 2013 StatusnuSTORM has received Stage I approval from FermilabOpens up opportunity for R&D funds to further development towards TDR/CDRResponse from SPSC:The SPSC recognizes the nuSTORM project as an important step in the long-term development of a neutrino factory, presently considered as the ultimate facility to study CP violation in the neutrino sector. nuSTORM would also constitute a test bed for accelerator and beam physics R&D. The Committee appreciates that, in addition to these long term goals, nuSTORM could also provide the opportunity to settle important questions in the sector of sterile neutrinos, and to perform precise neutrino cross section measurements for the future neutrino programmes.Currently, conventional long baseline LA-based programmes are being discussed in Europe (LBNO) and in the US (LBNE), aiming at the determination of CP violation in the neutrino sector on a shorter time scale than neutrino factories. The Committee notes that the nuSTORM collaboration is also exploring the possibility of being hosted by Fermilab and that there is a sizeable overlap with the LBNO community. All projects under discussion would involve a large amount of funding and resources, which calls for adequate cooperation and prioritisation within the neutrino community.In this context, the SPSC considers that, in line with the recently updated European Strategy, an involvement in nuSTORM could be part of the CERN contributions to the development of future neutrino programmes. A further review of the project would require a more focused proposal identifying which tasks could be performed at CERN within a more general project defined in cooperation with Fermilab and other contributing institutes.41Alan Bross EPSHEP2013 July 20, 2013 nuSTORM: ConclusionsThe Physics case:Simulation work indicates we can confirm/exclude at 10s (CPT invariant channel) the LSND/MiniBooNE resultnm and (ne ) disappearance experiments delivering at the