Tagged Neutrino Beams

Mathieu PERRIN-TERRIN* *Aix Marseille Univ, CNRS/IN2P3, CPPM, Marseille, France [email protected] Tagged Neutrino Beams 1. Introducing neutrino tagging 2. Testing neutrino tagging at NA62 3. Towards a full-scale tagged neutrino experiment: nuSCOPE 4. Perspectives and conclusions 02/10/2025 Tagged Neutrino Beams - M. Perrin-Terrin 2 Outline 02/10/2025 Tagged Neutrino Beams - M. Perrin-Terrin 3 Neutrino Tagging 𝜈 𝜇 𝑝 𝜋0 𝜋+ 𝑛 Neutrinos primarily studied through their interaction with the detector matter ν interaction are complex processes ν energy resolution ~20% ν flux precision ~10% 02/10/2025 Tagged Neutrino Beams - M. Perrin-Terrin 4 Neutrino Tagging 𝜈 𝜇 𝑝 𝜋0 𝜋+ 𝑛 Neutrinos primarily studied through their interaction with the detector matter ν interaction are complex processes ν energy resolution ~20% ν flux precision ~10% but... interaction is only half the story 02/10/2025 Tagged Neutrino Beams - M. Perrin-Terrin 5 Neutrino Tagging 𝜈 𝜇 𝑝 𝜋0 𝜋+ 𝑛 Neutrinos primarily studied through their interaction with the detector matter ν interaction are complex processes ν energy resolution ~20% ν flux precision ~10% Production processes are precisely measurable with trackers ν energy resolution <1% ν flux “perfectly” known (i.e. per-particle) μ+ π+ but... interaction is only half the story the other half is the neutrino production 𝜈 At a tagged experiment, neutrinos are the two sides (interaction/production) of a same coin! BEAM 02/10/2025 Tagged Neutrino Beams - M. Perrin-Terrin 6 Neutrino Tagging 𝜈 𝜇 𝑝 𝜋0 𝜋+ 𝑛 Neutrinos primarily studied through their interaction with the detector matter ν interaction are complex processes ν energy resolution ~20% ν flux precision ~10% Production processes are precisely measurable with trackers ν energy resolution <1% ν flux “perfectly” known (i.e. per-particle) μ+ π+ but... interaction is only half the story the other half is the neutrino production 𝜈 Challenge: 1010-11 π⁺/s At a tagged experiment, neutrinos are the two sides (interaction/production) of a same coin! Conceptualised by Pontecorvo (1980’s), but never implemented due to particle rate. [ Lett. Nuovo Cim. , 25 , 257-259 (1979) ] BEAM The Challenge – Beam Particle Rate 02/10/2025 Tagged Neutrino Beams - M. Perrin-Terrin 7 slow extraction static focussing (quadrupole) momentum selection At conventional beamlines (e.g. DUNE), instantaneous particle rate is “huge” (~1018 part/s) A tagged beam requires an alternative beamline design, using: •Slow extraction (few sec. long pulse instead of μs) with static focussing •Momentum selection (remove soft π’s) •Large (10x10cm²) beam transverse size (what really matters is part/s/cm²) and... high intensity trackers (next) A running demonstrator — NA62 02/10/2025 Tagged Neutrino Beams - M. Perrin-Terrin 𝐵 𝐾+→ 𝜋+𝜈𝜈 = 7.86 ± 0.61 × 10−11 K+→ μ+νμ JINST, 12(05):P05025, 2017. •Fixed target Kaon experiment at CERN SPS (2015-present) •Goal: measure in the SM •~1012 kaon decays per year, mostly •Instrumentation available to detect the 𝑲+, 𝝁+ and 𝝂𝝁CC interaction NA62 Simplified Layout 02/10/2025 Tagged Neutrino Beams - M. Perrin-Terrin 9 4.8s spill [ JINST , 14 , P07010 (2019) ] BEAM Beam line Design Tagged Neutrino Beams - M. Perrin-Terrin 16 18° separation with primary beam Quadrupole triplet to generate a shallow focus of the beam in decay tunnel (reduce bkg on calorimeter) Beam spectrometer to determine K, π •momentum (R4 + T1-4) •direction (T5-6) •time (T1-6) Beam Spectrum at Decay tunnel entrance Beam line Design 02/10/2025 Tagged Neutrino Beams - M. Perrin-Terrin 17 Calorimeter to identify and count e+and μ+ emitted at large angles (K⁺➔μ⁺ν) Muon spectrometer to determine the μ momentum, direction and time [EPJ C, 83 964 (2023)] μrange meter to identify & count μ emitted at small angles (π⁺➔μ⁺ν) Segmented calorimeter build from elementary cells Particle identification based on the energy deposit pattern Monitoring Instrumentation 02/10/2025 Tagged Neutrino Beams - M. Perrin-Terrin 18 Three radial layers of sampling calorimeter (iron/scintillator/Wave length shiting fibers) x 5 Two layers of scintillator to reject π0 (plastics scintillator, 400ps time reso) SiPM readout behind 30cm of boroted polyethylene Beam spectometer specifications •factor 10 beyond state of the art (NA62) •aligned with R&D for high lumi LHC (LHCb-VELO U2) see next Technology for the tagger 02/10/2025 Tagged Neutrino Beams - M. Perrin-Terrin Beam spectometer specifications •factor 10 beyond state of the art (NA62) •aligned with R&D for high lumi LHC (LHCb-VELO U2) see next Muon spectrometer •large tracking planes (~1m2) •hybrid solution envisaged: center region with pixel, outer region with cheaper technology (e.g. sci-fibers, micromegas) Technology for the tagger 02/10/2025 Tagged Neutrino Beams - M. Perrin-Terrin 20 Recall: Hybrid pixel detectors architecture High intensity pixel detectors 02/10/2025 Tagged Neutrino Beams - M. Perrin-Terrin 21 Sensor Readout ASIC Cooling 0.5% X₀(i.e. 0.5 mm of Si) •New sensors: planar ➔Trenched 3D High intensity pixel detectors 02/10/2025 Tagged Neutrino Beams - M. Perrin-Terrin 22 Planar 3D Std 3D Sensor Readout ASIC Cooling 0.5% X₀(i.e. 0.5 mm of Si) optimised electrode geometry Trenched 3D Time Reso [ps] Still <20ps time reso after massive irradiation ! •New sensors: planar ➔Trenched 3D •New ASIC: on-going R&Ds with 28nm CMOS: IGNITE (INFN) picoPix (CERN/Nikef) High intensity pixel detectors 02/10/2025 Tagged Neutrino Beams - M. Perrin-Terrin 23 Planar 3D Std 3D Sensor Readout ASIC Cooling 0.5% X₀(i.e. 0.5 mm of Si) optimised electrode geometry Trenched 3D Time Reso [ps] Still <20ps time reso after massive irradiation ! First ASICS are being tested ! •New sensors: planar ➔Trenched 3D •New ASIC: on-going R&Ds with 28nm CMOS: IGNITE (INFN) picoPix (CERN/Nikef) •Powerful cooling (>1W/cm2) using silicon micro-channel cooling plates pionneered by NA62/LHCb All building blocks are becoming available, now need to scale-up to full size detectors High intensity pixel detectors 02/10/2025 Tagged Neutrino Beams - M. Perrin-Terrin 24 Planar 3D Std 3D Sensor Readout ASIC Cooling 0.5% X₀(i.e. 0.5 mm of Si) optimised electrode geometry Trenched 3D Time Reso [ps] Courtesy:NA62 Still <20ps time reso after massive irradiation ! First ASICS are being tested ! •Reference detector: 500t of liquid argon (4x4x22.3m3) similar to protoDUNEs Improved time resolution (300ps) assuming more photon coverage (R&D for 3rd/4th DUNE detector) •On-going studies using a 100t water Cerenkov or WBLS detector •Proton consumption compatible with CERN physics program 1.4×1019POT in ~5 years Neutrino detector and interaction rates 02/10/2025 Tagged Neutrino Beams - M. Perrin-Terrin 25 Event per 1.4×1019 POT 500t LAr 100t Water νμ 1.3 × 106 Monitored νμ 1.0 × 106 Tagged νμ 0.76 × 106 0.14 × 106 νₑ 1.7 × 104 Monitored νₑ 1.2 × 104 π➔μν K➔μν Ke3 νμνₑ Large samples of νμ(106) and νe(104) with •precise ν flux knowledge: <1% flux precision for νe(from independant techniques) per-particle tracking for tagged νμ •νμenergy known with <1% precision event-by-event ➔Neutrino Interaction (see next 2 slides and in F. Bramati Talk on Thursday) ➔Searches for new physics: ➔Beyond neutrino physics •Nuclear Physics/QCD: tagged-ν are ideal to probe to hadronic matter (axial current, form factors) •Kaon physics ? rare/forbiden kaon decays exploiting the large kaon decay sample (1015/year) Unique Physics Case 02/10/2025 Tagged Neutrino Beams - M. Perrin-Terrin 32 μ+ π+ K⁺ 𝜈 Decay: e.g. HNL: π⁺,K⁺➔μ⁺N Propagation/Oscillation: sterile ν Interaction: e.g. mono-ν A selected sample of studies 02/10/2025 Tagged Neutrino Beams - M. Perrin-Terrin 33 νμcross section energy dependence: crucial to extrapolate flux between near and far detectors Triple differential t 400t of Argon CC inclusive 100t of Water CC inclusive integration width no more driven by resolution but by statistics ! 1% stat. error 1% stat. error Preliminary A selected sample of studies 02/10/2025 Tagged Neutrino Beams - M. Perrin-Terrin 34 νμcross section energy dependence: crucial to extrapolate flux between near and far detectors Triple differential t 400t of Argon CC inclusive 100t of Water CC0π inclusive integration width no more driven by resolution but by statistics ! 2% stat. error 1% stat. error Preliminary A selected sample of studies 02/10/2025 Tagged Neutrino Beams - M. Perrin-Terrin 35 A selected sample of studies 02/10/2025 Tagged Neutrino Beams - M. Perrin-Terrin 36 A selected sample of studies 02/10/2025 Tagged Neutrino Beams - M. Perrin-Terrin 37 electron-scattering like measurements but with νμ Triple differential t νe/νμcross-section ratio can be measured at 2% precision using the PRISM tehcnique to match the νμspectrum to the νeone one of the dominant systematic uncertainties for leptonic CP violation [ Nature , 599 , 565--570 (2021) ] Feasibility studies conducted by CERN Accelerator & Technology Sector •3 sites identified (North Area, CNGS, West Area) •Proton sharing is compatible with other fixed target experiments (e.g. SHiP) Implementation 02/10/2025 Tagged Neutrino Beams - M. Perrin-Terrin 38 Feasibility studies ongoing under the umbrella of Physics Beyond Colliders West Area Option (Meyrin) West Area CNGS nuSCOPE: project for a short baseline tagged and monitored experiment at CERN Unique features: •Known flux νe(<1% precision) and νμ(per-particle) •νμenergy known event-by-event (<1% precision) and independently of its interaction •Large tagged νμ(7.6 ⨯105) and monitored νe(1.2 ⨯10⁴) samples Compelling physics program •Centered on ν interaction to support DUNE/HyperK •Being extended (BSM, QCD, nuclear...) Technological readiness well advanced but key R&D and challenges remain (integration at CERN, high intensity pixel detectors, sub-nano section ν detectors) •You are very welcome to join ! Summary 02/10/2025 Tagged Neutrino Beams - M. Perrin-Terrin 39 Kickoff Workshop at CERN on October 13-15 2025. https://indico.cern.ch/event/1548855/ Can ν tagging be implemented for long baseline experiment ? •Challenge: get large ν samples with beam intensities compatible with the tracker capabilities •Potential solution: use very large detectors like KM3NeT-ORCA (7Mton) Detectors are coarser than DUNE or HyperK but ν-tagging would compensate •Very prelimiary studies from Protvino to ORCA gave encouraging results as well as beamline studies conducted within CERN-PBC Long term perspectives for neutrino tagging 02/10/2025 Tagged Neutrino Beams - M. Perrin-Terrin 40 [Eur. Phys. J. C (2022) 83:465] CERN KM3NeT Sites Precision on dCP [ EPJ C , 84 (2024) ] HK Conclusions 02/10/2025 Tagged Neutrino Beams - M. Perrin-Terrin 41 ... allowing a first tagged neutrino candidate to be detected, ... enabling particle tracking at ever-higher intensities •Neutrino tagging is a strong asset for the upcoming precision era (sub-percent energy resolution, per-particle flux control) •Since Pontecorvo introduced this idea, technologies have advanced... Time Reso [ps] More on nuSCOPE in F. Bramati Talk tomorrow ...such that afirst full-scale tagged neutrino experiment could be built in the next decade Beamline Instrumentation 02/10/2025 Tagged Neutrino Beams - M. Perrin-Terrin 48 Tagging Detectors to reconstruct νμfrom π⁺➔μ⁺ν (& K⁺➔μ⁺ν) •Beam spectrometer to determine K, π momentum (T1-4), direction (T5-6) and time (T1-6) •Muon spectrometer to determine the μ momentum, direction and time Monitoring Detectors to estimate the neutrino flux from K⁺➔π⁰e⁺νe, K⁺➔μ⁺ν, π⁺➔μ⁺ν •calorimeter to identify and count positrons and μ emitted at large angles (K⁺➔μ⁺ν) •muon range meter to identify and count μ emitted at small angles (π⁺➔μ⁺ν) A first attempt... 02/10/2025 Tagged Neutrino Beams - M. Perrin-Terrin 49 Iron Muon Detector E M Trackers ν http://web.ihep.su/library/pubs/prep1997/ps/97-32.pdf “The dotted line shows the νe trajectory calculated for a Kμν decay detected in the tagging station.” Serphukov, 1980’s : the Tagged Neutrino Facility (TNF) using the Big ARgon Spectrometer (BARS): 2 x 216t of LAr Stopped in the 1990’s, limited legacy