Detector Baseline EuroNu Meeting, RAL 20 January 2010 Paul Soler

Neutrino Factory Far Detector Baseline Two MIND detectors: one of 100 kton at distance 2000-4000 km and one of 50 kton at 7500 km Dimensions: 15x15m2, length 50-100m, segmentation 3 cm Fe, 2 cm scintillator No performance is gained from adding silver detector iron (3 cm) + scintillators (2cm) n beam 15 m B=1 T 50-100kT 50-100 m EuroNu, RAL, 20 January 2011

Neutrino Factory Far Detector Baseline Performance obtained in latest MIND analysis, efficiencies and migration matrices are now also part of baseline Numu efficiency Anti-numu efficiency EuroNu, RAL, 20 January 2011

Baseline mass of intermediate detector What mass should be adopted for detector at 2000-4000 km? Two possibilities (50 or 100 kton): baseline now set at 100 kton The 7500 km detector remains at 50 kton since no significant improvement Winter IDS-NF-007 Back: ±20% Near/far:±2.5 Matter: ±2% Effect of Having no systematics EuroNu, RAL, 20 January 2011

Neutrino Factory Far Detector Baseline New geometry now approaching octagonal design (14 m), as in MINOS, to be able to implement toroidal field (1-2.2 T) This is not baseline yet since performance not know, but will probably become baseline after performance determined EuroNu, RAL, 20 January 2011

Silver Channel Far Detector Silver channel detector and standard oscillations: A nent (silver) detector was useful for removal of degeneracies in conjunction with golden channel at MIND An Emulsion Cloud Chamber (ECC) type detector, as in Opera, was considered as part of ISS baseline However, two MIND detectors, one at 4000 km and one at 7500 km, has better dCP vs q13 coverage than MIND+ECC, especially since energy of NF muons is now 25 GeV (ie. less taus) No performance is gained from adding silver channel detector EuroNu, RAL, 20 January 2011

Tau Far Detector in Baseline Non standard interaction: At source: At detection: Through propagation: Winter, IDS-NF-08: Test of non-unitarity, measure all probabilities: Better to do in Near Detector No improvement from silver channel at FD Kopp, Ota, Winter PRD 78, 053007, 2008 EuroNu, RAL, 20 January 2011

Tau Far Detector in Baseline Sterile neutrino (3+1): The nm disappearance plus nm → nt appearance adds information about sterile neutrino mixing angle However, better to have tau detector at magic baseline for this analysis. Final conclusions: A tau far detector not essential for standard oscillation physics programme or for NSI in propagation Better to concentrate on NSI at source and detection at near detector Donini et al, arXiV:0812.3702 EuroNu, RAL, 20 January 2011

Water Cherenkov Baseline The MEMPHYS detector at Frejus tunnel is baseline for CERN based SPL Super Beam or Beta Beam (130 km) Size: three modules of 3x65mx60m (440 kton) or 3x65mx80m (572 kton) being considered Photocathode coverage: 30% Considering 81,000 12” PMTs per module (but options are 8” or 10”) MEMPHYS 440 kt 65m 60m EuroNu, RAL, 20 January 2011

Near Detectors Baseline is to have one ND per straight per ring (ie 4 detectors) Need to check if one ND can measure beam divergence ~0.1/g What is optimum distance: between 80-1000 m How much shielding do we need? EuroNu, RAL, 20 January 2011

Near Detector Block Diagram Near Detector design will need three sections: Vertex detector for charm/tau measurement at the front. High resolution section (SciFi tracker or TRT tracker) for leptonic flux measurement Mini-MIND detector for flux and muon measurement n beam 3 m B>1 T ~20 m High Res Detector Mini-MIND Vertex Detector EuroNu, RAL, 20 January 2011

Baseline: Scintillating Fibre Tracker One station: 4 planes fibres (4mm+ 50 mm scintillator) 20 stations Dimensions: 1.5x1.5x1.1 m3 (2.5 tonnes) 23,000 fibres/station x 20 stations Can deliver leptonic physics programme at ND EuroNu, RAL, 20 January 2011

Alternative: High resolution TRT High resolution magnetised detector (HiResMn) LBNE near detector proposal Mishra, Petti, South Carolina EuroNu, RAL, 20 January 2011

Tau/Charm detector Silicon vertex detector for tau/charm: Use NOMAD-STAR as a model for this detector NOMAD-STAR had 5 layers silicon 72cmx31cm with B4C target (45 kg) In Neutrino Factory would need more layers but similar mass (~100 kg) References: NIMA 413 (1998), 17; NIMA 419 (1998), 1; NIMA 486 (2002), 639; NIMA 506 (2003), 217; NIMA 569 (2006), 127) EuroNu, RAL, 20 January 2011

NOMAD-STAR and charm Used NOMAD-STAR to search for charm events Used impact parameter performance (measured at 33mm) of NOMAD-STAR and kinematic constraints of D0, D+, Ds+ decays Efficiencies from analysis: 3.5% for D0, D+ and 12.7% for Ds+ detection Fiducial volume small (72cmx36cmx15cm), only 5 layers and only one projectionwould improve with more layers (to be studied) From 108 CC events/yr (0.1 ton), about 3.1x105 reconstructed charm M.Ellis PhD thesis; J.Phys G.29 (2003), 1975; NIMA 569 (2006), 127) EuroNu, RAL, 20 January 2011

Tau detection through impact parameter Impact parameter technique through Si vertex detector (NAUSICAA) was studied in NIMA 378 (1996), 196. Impact parameter resolution nm-CC=28mm Impact parameter resolution nt-CC=62mm Efficiencies: tm: e=10% tp(np0): e=10% tppp(np0): e=23% Total eff: e=0.85x10%+0.15x23%=12% st/sm=0.49 for <En>~23 GeV d~90mm nm nt EuroNu, RAL, 20 January 2011

Neutrino Factory Near Detector for taus? Rates: approx 108 nm CC events/year in 0.1 ton detector Assume 12% eff from NAUSICAA and st/sm=0.49 Tau looks like charm so charm background a problem Inclusive charm production at 27 GeV (from CHORUS): 6.4±1.0% From 10-30 GeV: ~4%4x106 charm events!! Charm produced in CC reaction with d or s quark so always have lepton Associated charm in NC interaction (see charm review De Lellis et al. Phys Rep 399 (2004), 227-320) For anti-ne background could create D- which looks like signal, but need to identify e+ to reject background!!! So, very important to have light detector (ie Scintillating Fibre tracker) behind vertex detector to identify positron (B-field as well) with high efficiency: assume ~50% (still have 2x106 background for 3.5x106 signal) Even if we could use kinematic methods a la NOMAD to reduce all background: (in 0.1 ton) Very tough analysis! EuroNu, RAL, 20 January 2011 Current NOMAD best limit:

Conclusions MIND detectors at 4000 km with 100 kton and 7500 km with 50 kton mass is baseline for NF Silver channel has been removed from NF baseline since it doesn’t improve sensitivity or NP reach Water Cherenkov detector (MEMPHYS) includes three modules 65m diameter with 60m height (440 kt) but studying increasing to 80m height (572 kt) Near detectors: Four detectors at each straight of storage ring Three components at NF: vertex + SciFi tracker + muon spectrometer For SB and BB do not need vertex detector SciFi tracker: 2.5 ton Tau/charm can be reconstructed in 0.1 ton vertex detector – charm analysis feasible but tau analysis for NSI difficult due to wrong sign charm background at NF EuroNu, RAL, 20 January 2011