1. Summary Near Detector at IDS Meeting in FNAL EuroNu Annual General Meeting, Strasbourg 3 June 2010 Paul Soler

2. 2 EuroNu AGM Strasbourg, 2 June 2010 Near Detector Aims o Currently there is no near detector baseline o So far, we know that we need a near detector but not what it looks like, nor how far away it should be from the decay ring o We have decided on some of the essential measurements that a Near Detector needs to do to reduce the neutrino oscillation systematics: –Measurement of neutrino flux and extrapolation to Far Detector –Measurement of charm (main background to oscillation signal) –Cross-section measurements: DIS, QEL, RES scattering o Other desirable measurements with Near Detector –Fundamental electroweak and QCD physics (ie PDFs) –Search for Non Standard Interactions (NSI) from taus o Have established links with LBNE near detector since many of the issues are similar

3. 3 EuroNu AGM Strasbourg, 2 June 2010 Near Detector Rationale o Importance of Near Detector for systematics o 2.5% error on flux makes big difference in CP coverage Winter, Tang

4. 4 EuroNu AGM Strasbourg, 2 June 2010 High Resolution Low Mass Near Detector  Simulation near detector by Sofia group (Tsenov/Kharadzhov): GENIE+GEANT4, simple digitization, smearing but no reconstruction yet

5. 5 EuroNu AGM Strasbourg, 2 June 2010 Flux Measurement at Near Detector  Tsenov/Kharadzhov showed how Inverse Muon Decay (IMD) can be used for flux measurement: Best assumption for simulation: δθ~0.1mrad δp/p~1% δ E/E~1% Shows parameters that we should strive for in the detector 1 hour NF!!! 3.1x10 6 /year Is ~1% flux error achievable?

6. 6 EuroNu AGM Strasbourg, 2 June 2010 Flux extrapolation to far detector Hardly any change in error contours by adding ND information. Still need to extract systematic error as function of  and  13 from method o Flux extrapolation method based on matrix propagation. Laing, PS

7. 7 EuroNu AGM Strasbourg, 2 June 2010 Charm measurement o Motivation: measure charm cross-section to validate size of charm background in wrong-sign muon signature o Charm cross-section and branching fractions poorly known, especially close to threshold o Semiconductor vertex detector only viable option in high intensity environment (emulsion would perish) CHORUS 2008

8. 8 EuroNu AGM Strasbourg, 2 June 2010 Cross section measurements o Measurement of cross sections in DIS, QEL and RES.  Coherent and diffractive  o Different nuclear targets: H 2, D 2 o Nuclear effects, nuclear shadowing, reinteractions At NUFACT, with modest size targets can obtain very large statistics, but is <1% error achievable? What is expected cross- section errors from MiniBoone, SciBoone, T2K, Minerva, before Neutrino Factory?

9. 9 EuroNu AGM Strasbourg, 2 June 2010 Number Near Detectors o Might need more than one detector at each decay ring straight sections –While magnetic field not essential, it is preferable  Two detectors allows one also to measure divergence of beam ~0.1/ , without Cherenkov monitor along decay straight

10. 10 EuroNu AGM Strasbourg, 2 June 2010 Flux Observed by Near Detector  Near Detector sees a line source (755 long decay straight)  Far Detector sees a point source 130 m 1 km 130 m 1 km2500 km ND FD

11. 11 EuroNu AGM Strasbourg, 2 June 2010 Near Detector Design o Overall design of near detector(s): –We need near detector(s) –We don’t know what it/they should look like –However, we probably need: Vertex detector for charm and tau interactions for NSI (but beware of tau production from D s decay!!) Low Z high resolution target (ie scintillating fibre tracker or capillary tube tracker) for flux and cross-section measurement (   and e ) Magnetic field for muon momentum measurement ( δp/p~1%) Need muon catcher and electron identification Good energy resolution for flux extrapolation (better than Far Detector) – aspire to δE/E~1% Magnetic fields not essential for two (or more) detectors at each ring, but I think needed for momentum resolution

12. 12 5th Neutrino Factory International Design Study Meeting FNAL, 9 April 2010 Near Detector Design o Near Detector elements: –Vertex detector: Choice of Pixels (eg. Hybrid pixels, Monolithic Active Pixels …) or silicon strips –Tracker: scintillating fibres, gaseous trackers (TPC, Drift chambers, straw tubes …) –Other sub-detectors: PID, muon ID, calorimeter, … o Joint meeting of LBNE near detector proponents and IDS-NF near detector effort showed that there are areas of overlap and obvious synergies between both detector communities o Need to adapt these ideas for near detector at a neutrino factory.

13. 13 EuroNu AGM Strasbourg, 2 June 2010 o Bradford showed that a recycled Minerva detector could serve as near detector for LBNE: ideas also for neutrino factory Minerva-like detector Outer calorimetry Tracking volume of fine-grained scintillator Readout PMT’s LHe Veto Wall Cryotarget

14. 14 EuroNu AGM Strasbourg, 2 June 2010 o Hybrid design based around Minerva technology: Hybrid Minerva design Tracking/calorimetry units: Minimize distance  travels before hitting calorimetry (sign discrimination threshold ~200 MeV). Repeated units increase fiducial volume/statistics. Side calorimetry Bradford

15. 15 EuroNu AGM Strasbourg, 2 June 2010 o Mishra argued strongly that identical near/far detectors are insufficient, so need high resolution near detector High resolution near detector Mishra

16. 16 EuroNu AGM Strasbourg, 2 June 2010  High resolution magnetised detector (HiResM ) High resolution near detector Mishra

17. 17 EuroNu AGM Strasbourg, 2 June 2010 o NOMAD-like resolution in HiRes detector allows to: –Measure flux (low 0 method): –Compare to Inverse Muon Decay –Measure absolute flux using -e elastic scattering –Measure quasi-elastic scattering –Fermi motion –NC vs CC events (NOMAD with 90% purity) –Coherent  0 –Measure A dependence in nuclear targets –Comparison sin 2  W from DIS and –77 different physics topics! High resolution near detector Mishra

18. 18 EuroNu AGM Strasbourg, 2 June 2010 Muon chambers EM calorimeter Hadronic Calorimeter o The previous design already looks like the detector configuration that I have shown in the past (based on NOMAD and T2K): –Need also to add vertex detector in front One possible design

19. 19 EuroNu AGM Strasbourg, 2 June 2010 o Make design more similar to Far Detector: –Can have a high resolution Mini-TASD for leptonic measurement and a mini-MIND for flux and muon measurement –Vertex detector for charm measurement at the front. –Need to study options with detailed simulations Another possibility beam 3 m B=1 T ~20 mMini-TASD 95 t Mini-MIND 460 t VertexDetector

20. 20 5th Neutrino Factory International Design Study Meeting FNAL, 9 April 2010 Tasks and conclusions o Tasks: –Simulation of near detector and optimisation of layout: benefit from common software framework for Far Detector –Flux determination with inverse muon decays, etc. –Analysis of charm using near detector –Determination of systematic error from near/far extrapolation –Expectation of cross-section measurements –Test beam activities to validate technology (eg. vertex detectors, tracking detectors) –Construction of beam diagnostic prototypes –Other physics studies: PDFs, etc. (engage with theory community for interesting measurements)