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Neutrino Studies at an EIC Proton Injector

Neutrino Studies at an EIC Proton Injector. Jeff Nelson College of William & Mary. Outline. A highly selective neutrino primer Including oscillations (what & why we believe) Neutrino sources (now & future) Beams Example concepts & proposals for next decade and beyond

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Neutrino Studies at an EIC Proton Injector

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  1. Neutrino Studies at an EIC Proton Injector Jeff Nelson College of William & Mary

  2. Outline • A highly selective neutrino primer • Including oscillations (what & why we believe) • Neutrino sources (now & future) • Beams • Example concepts & proposals for next decade and beyond • What will we be studying in 10+ years? • Summary of yesterday’s neutrino session • Short baseline • Neutrino properties • Neutrinos interactions and neutrinos as probes • Long baseline – oscillation physics • Novel beams • Where an EIC proton injector could fit into this future

  3. Cliffs Notes on Neutrinos • There are only 3 “light” active neutrino flavors (from Z width) • Electron, muon, & tau types • Cosmological mass limits imply ∑mν< 0.7 eV (WMAP + Ly-a) • Oscillations imply at least one neutrino greater than 0.04 eV (more later) • Basic interactions => basic signatures • Cross sections crudely linear with energy • Charged current (CC) • The produced lepton tags the neutrino type • Has an energy threshold • Neutrino’s energy converted to “visible” energy • Neutral current (NC) • No information about the neutrino type • No energy threshold • Some energy carried away by an out-going neutrino • Electron scattering (ES)

  4. Oscillation Formalism 1.0 P(vm->nm) 0.0 0 1 2 3 4 5 6 7 8 9 10 E (GeV) • With 2 neutrino basis (weak force & mass) there can be flavor oscillations • The probability that a neutrino (e.g. nm ) will look like another variety (e.g. nt ) will be P(nm nt ; t)= |<nt|nm (t)>|2 • A 2-component unitary admixture characterized by q results in P(nm nt ) =sin22qsin2(1.27Dm2L/E) • Experimental parameter L (km) /E (GeV) • Oscillation (physics) parameters sin22q(mixing angle) Dm2 = mt2 - mm2 (mass squared difference, eV2) Dm2 = 0.003 eV2; L = 735 km

  5. 3-Flavor Oscillation Formalism • In 3 generations, the mixing is given by • Where, and • There are 3Dm2’s (only 2 are independent) • 2 independent signs of the mass differences • There are also 3 angles and 1 CP violating phase • Predicts: CPV, sub-dominate oscillations (all 3 flavors) • Matter effects (MSW) • Electron neutrinos see a different potential due to electrons in matter

  6. How do we know what we know? • In the past decades there have been many oscillation experiments in many forms • Neutrino sources • Reactor neutrinos • Solar neutrinos • Supernovae • Atmospheric neutrinos (cosmic rays) • Heavy elements concentrated in the Earth’s core • Accelerator neutrinos • Luckily we are converging to just a few important facts…

  7. Solar Neutrinos: Case Closed • Sun emits neutrinos while converting H to He • The overall neutrino production rate is well known based on the amount of light emitted by the sun • There are too few electron neutrinos; seen by a number of experiments • From SNO’s NC sample we know the overall solar flux is bang on • Looks like ne => nactive oscillations w/MSW • KamLand, a ~100 km baseline reactor experiment, confirms • A very consistent picture Phys. Rev. Lett. 89, 011301 (2002) hep-ex/0212021

  8. Atmospheric Neutrinos n L ~ 20 km Earth n n n n L ~ 104 km n Super K • Consistent results • Super K results are the standard; other experiments are consistent • Electrons show no effect • Reactors give the best limits • Matter effects tell us it’s a transition to normal neutrinos M. Ishitsuka NOON04

  9. LSND • They observe a 4s excess of ne events • Spatial distributions as expected • Allowed region strongly constrained by other experiments Phys. Rev. D 64, 112007 (2001).

  10. Parameter Summary • The 3 mass signatures are not consistent with 3 neutrinos • Either • A signature is incorrect • Or there is another non-interacting type of neutrino (aka sterile) • Or CPT volation • Miniboone testing LSND result at Fermilab right now Adapted from H. Murayama; PDG

  11. Current Summary of Active Neutrino Parameters (ignoring CPT and/or sterile) • Mass splittings • Angles

  12. K2K ExperimentMan-Made Neutrinos • Neutrinos from KEK to SuperK • Pp = 12 GeV • Goal of 1020 protons on target (POT) • 5 kW beam power • Baseline of 250 km • Running since 1999 • 50 kT detector • They see 44 events • Based on near detector extrapolations, they expected 64 ± 6 events without oscillations • Results are consistent with atmospheric data but not yet statistically compelling hep-ex/0212007 (K2K)

  13. The Next 5 Years • The current generation of oscillation experiments are designed to • Confirm atmospheric results with accelerator n’s (K2K) • Resolve sterile neutrino situation (MiniBooNE; more later) • Demonstrate oscillatory behavior of nm’s (MINOS) • Refine the solar region (KamLAND) • Demonstrate explicitly nmnt oscillation mode by detecting nt appearance (OPERA) • Precise (~10%) measurement of ATM parameters (MINOS) • Improve limits on nmne subdominant oscillation mode, or detect it (MINOS, ICARUS) • Test of matter effects (SNO)

  14. Long Baseline Example:MINOS Detectors & NuMI Beam A 2-detector long-baseline neutrino oscillation experiment in a beam from Fermilab’s Main Injector Near Detector: 980 tons Far Detector: 5400 tons

  15. On the Fermilab Site • 120 GeV Main Injector’s (MI) main job is stacking antiprotons and as an injector in the Tevatron • Most bunches are not used required for p-bar production • So… • Put them on a target and make neutrinos • Same thing is also done with the 8 GeV booster

  16. Making a Neutrino Beam Wilson Hall for Scale Muon Monitors Absorber Hall Proton carrier Target Hall Decay volume Near Detector Hall

  17. NuMI Beam & Spectra nm CC Events/kt/year Low Medium High 470 1270 2740 nm CC Events/MINOS/2 year Low Medium High 5080 13800 29600 4x1020 protons on target/year 4x1013 protons/2.0 seconds 0.4 MW beam power (0.25 MW initially)

  18. Target & Horn Target • Graphite target • Magnetic horn (focusing element) • 250 kA, 5 ms pulses

  19. NuMI Target Hall

  20. MINOS Charged-Current Spectrum Measurement

  21. Status in ~5 Years • We will know • Both mass differences (Kamland, MINOS) • 2 of the 3 angles @ 10% (Kamland+SNO; SK+MINOS) • Sign of one of the mass differences (Solar MSW) • First tests of CPT in allowed regions (MINOS, MiniBooNE) • Probably still missing • Last angle? * • Confirmation of matter effects * • Sign of the other mass difference; mass hierarchy * • CP in neutrinos * • Absolute mass scale (double beta; cosmology) • Majorana or Dirac (double beta) * addressable with “super beam” experiments

  22. Super Beam Rules of Thumb • It’s the [proton beam power] x [mass] that matters • Crudely linear dependence of pion production vs Eproton • Generally energy & cycle time are related and hence the power is conserved within a synchrotron • Remember that we design an experiment at constant L/E • The beam divergence due to the energy of the pions is balanced by the boost of the pions and the v cross section at constant L/E

  23. Long Baseline Goals • Find evidence for nmne • One small parameter in phenomenology • Determine the mass hierarchy • Impacts model building • Is q23 exactly equal to 1??? – test to 1% level • Precision measurement of the CP-violating phase d • Cosmological matter imbalance significance • Potentially orders of magnitude stronger than in the quark sector • Resolve q ambiguities • Significant cosmological/particle model building implications

  24. Super Beam PhasingPart of the DoE Roadmap • Phase I (~next 5 years) • MINOS, OPERA, K2K • Phase II (5-10 years) • 50kt detector & somewhat less than 1 MW • J2K, NOnA, super reactor experiment • Phase III (10+ years; super beams) • Larger detectors and MW+ beams • JPARC phase II + Hyper K (Mton ĉ) • NuMI + Proton driver + 2nd 100kt detector • CERN SPL + Frejus (0.5 Mton ĉ) • BNL super beam + UNO (0.5 Mton ĉ) @ NUSL • Phase IV (20 years ???) • Neutrino factory based on muon storage ring

  25. Phase II e.g. Off-Axis Searches for ve Appearance • 2 off-axis programs • JPARC to Super K (T2K; Funded) • NuMI to NOnA (Under Review) • Main goal • Look for electron appearance <1% (30X current limits) • Off-axisdetector site to get a narrow-band beam • Fine-grain detectors to reduce NC po background below the intrinsic beam contamination • Statistics limited for most any foreseeable exposure NuMIOn-axis

  26. There are matter effects visible in the 820km range Provides handle on CP phase, mass hierarchy but… Ambiguities with just a single measurement In addition If sin2(2q23) = 0.95 sin2(q23) = 0.39 or 0.61 Cosmology cares Rough equivalence of reactor & antineutrino measurements Eventually need 2nd energy (AKA detector position) in same beam to resolve at narrow-band beam Interpretation of Results NOnA Goal

  27. Phase IIIe.g. BNL Super Beam + UNO • Turn AGS into a MW beam • 10X in AGS beam power • Not same upgrades as eRHIC • Use a very long baseline • Wide-band or off-axis beam • White paper released • Mton-class proton decay detector called UNO envisioned at the National Underground Lab (NUSL) • Location not picked but any of the possibilities are compatible with this concept • LOI to funding agencies this year EIC NuSL ~2500 km

  28. Very Long Baselines Somewhat Improved Reach & … Wide-band beam accesses a large range of the spectrum gives access to resolve all ambiguities

  29. Near future short baseline program Recent proposals • MINERvA @ main injector • FINeSSE @ Fermilab booster • Fine grained devices • Most topics will still benefit from higher Stats MINERvA

  30. Short Baseline Neutrinos • Neutrino properties • Sterile neutrinos after MiniBooNE (few eV2 range) • R-process in supernovae astro-ph/0309519 hep=ph/0205029 suggests searches beyond LSND indicated region • Magnetic moment • Required if massive Dirac neutrinos • Suggested by beyond SM models • Models go from minimal BSM model of 3x10-19 µB to current limits of 6.8x10-10µB (in vµ) • Neutrinos as a probe of nucleon structure • Form factors (low energy) • Current generations to probe to Ds ~ ± 0.04 • Structure Functions (higher-energy)

  31. Sterile Beyond LSND/MiniBooNE • Current proposals a more coverage for sterile neutrinos through controlling systematics with 2-detector measurements • An EIC class injector would allow the statistics to fully exploit this approach • Needs study to determine the possible reach and systematic limits

  32. Oscillation experiments run in the sub GeV to few GeV range • Extracting neutrino spectra complicated by using an energy range where a lot of things matter • Quasi-elastic, resonance production and DIS contribute significantly • Coherent mechanisms important • The difference between Evis and Ev due to nuclear effects, Fermi motion, rescattering … • Also requires a subtraction of NC events that fake low energy CC events • Neutrino experiments rely on MC • A useful collaboration between neutrino & electron scattering communities promises to be useful for both • NuInt conference series • 3rd meeting this week at Gran Sasso • http://nuint04.lngs.infn.it/

  33. “Medium Energy” Physics A high-intensity neutrino beam offers new possibilities for the study of nucleon and nuclear structure. e.g. NuMI has very similar kinematic coverage to current generation of JLab experiments. A new window on many of the questions currently being explored in JLab experiments.

  34. Physics Goals • Quasi-elastic (n + n --> m-+ p, 300 K events off 3 tons CH) • Precision measurement of s(En) and ds/dQ important for neutrino oscillation studies. • Precision determination of axial vector form factor (FA), particularly at high Q2 • Study of proton intra-nuclear scattering and their A-dependence (C, Fe and Pb targets) • Resonance Production (e.g. n + N ---> n /m- + D, 600 K total, 450K 1p) • Precision measurement of s and ds/dQfor individual channels • Detailed comparison with dynamic models, comparison of electro- & photo production, the resonance-DIS transition region -- duality • Study of nuclear effects and their A-dependence e.g. 1 p<-- > 2 p <--> 3 p final states • Coherent Pion Production (n + A --> n /m- + A + p, 25 K CC / 12.5 K NC) • Precision measurement of s(E) for NC and CC channels • Measurement of A-dependence • Comparison with theoretical models

  35. Physics Goals • Nuclear Effects (C, Fe and Pb targets) • Final-state intra-nuclear interactions. Measure multiplicities and Evis off C, Fe and Pb. • Measure NC/CC as a function of EH off C, Fe and Pb. • Measure shadowing, anti-shadowing and EMC-effect as well as flavor-dependent nuclear effects and extract nuclear parton distributions. • MINERnA and Oscillation Physics • MINERnA measurements enable greater precision in measure of Dm, sin2q23 in MINOS • MINERnA measurements important for q13 in MINOS and off-axis experiments • MINERnA measurements as foundation for measurement of possible CP and CPT violations in the n-sector • sT and Structure Functions (2.8 M total /1.2 M DIS events) • Precision measurement of low-energy total and partial cross-sections • Understand resonance-DIS transition region - duality studies with neutrinos • Detailed study of high-xBj region: extract pdf’s and leading exponentials over 1.2M DIS events • Most all of these would benefit from 10x or more statistics beyond proposals

  36. Physics Goals • Strange and Charm Particle Production (> 60 K fully reconstructed exclusive events) - • Exclusive channel s(En) precision measurements - importance for nucleon decay background studies. • Statistics sufficient to reignite theorists attempt for a predictive phenomenology • Exclusive charm production channels at charm threshold to constrain mc • Generalized Parton Distributions (few K events) • Provide unique combinations of GPDs, not accessible in electron scattering (e.g. C-odd, or valence-only GPDs), to map out a precise 3-dimensional image of the nucleon. MINERnA would expect a few K signature events in 4 years. • Provide better constraints on nucleon (nuclear) GPDs, leading to a more definitive determination of the orbital angular momentum carried by quarks and gluons in the nucleon (nucleus) • provide constraints on axial form factors, including transition nucleon --> N* form factors

  37. Beta Beam Concept • Goal is to make a very well understood neutrino beam (flux, spectrum, and no background) • Zuchelli (2002) • Start with radioactive ions • Use ions that beta decay with high Q and reasonable lifetime • Boost them with a  in the range 55 to 140 • Result would be a highly collimated beam

  38. Beta beams recently proposed for • High Energy q13 & CP violation • Low Energy Neutrino – nucleus interactions • Lowest Energy Neutrino Magnetic Moments

  39. Example Design from CERN • Lindroos (2003)

  40. CP violation & q13 • CERN vision for oscillation studies uses 200 km baseline with 0.44 Mton detector • For q13 = 3 deg appearance rates (10 yr) • 18Ne 66 events (osc,) • 6He 32 events (osc.) • T Violation test •  beam vs conventional ve=> vµ vµ => ve

  41. Neutrino-Nucleus Interactions • Lower energy beta beam (boosted to 10s of MeV) • Applications for astrophysics • Supernova neutrino detection • Supernova nucleosynthesis • Solar Neutrino Detection • Currently • Carbon only know to 4% - 10% • D, 56Fe, 127I reported with ~40% error • Cross sections ~ 10-41cm2 • Can make a 10% measurement in 10 ton detector with 1015 v/s over in a reasonable run Volpe (2003)

  42. Magnetic Moment • Neutrinos have mass there therefore the have a magnetic moment • Very sensitive to physics beyond the standard model • Current limits vary by species but are in the range of 10-15mB (e.g. from reactor studies) • Would need 1015 ions/s for reasonable sensitivity

  43. Beam Intensity • Current experiments near-term experiments (next 5 years) are fraction of a MW beam power • Few x 1020 to 1021 protons on target • eLIC booster in routine use on target • (1-3)x1022 per year • Up to 4MW • Each generation proposes factor of 10 X in [mass] x [power]

  44. Current, Planned, & Dream Super Beam Facilities Program Pp Ev P (MW) L (km) yr K2K 12 1.5 0.005 250 99 MiniBooNE 8 0.7 0.05 0.5 02 NuMI (initial) 120 3.5 0.25 735 05 NuMI (full design) 120 3.5 0.4 735 08 CNGS 600 17.0 0.2 735 05 JPARC to SK 50 1.0 0.8 295 08 NOnA (NuMI Off-Axis) 120 1.5 0.4 810 09 SNS 1.3 0.1 1.4 0.02 soon? Super Reactor n/a 0.01 10 1 5 yrs? JPARC phase II 50 0.8 4 295 Fermilab Proton driver 120 1.8 1.9 735/1500 CERN SPL (proton linac) 2 0.3 4 130 AGS Upgrade 30 1-7 2 2500 eLIC injector 20 1-5 4 2500 Now/next couple years~5 years 10-15 years

  45. Relationship to EIC Complexes To RHIC To Target Station High Intensity Source plus RFQ 200 MeV Drift Tube Linac BOOSTER AGS 1.2 GeV  28 GeV 0.4 s cycle time (2.5 Hz) 200 MeV 400 MeV Superconducting Linacs 800 MeV 1.2 GeV 0.2 s 0.2 s • At BNL • Use AGS for a neutrino program while is also feeding RHIC & eRHIC • At JLab • Use Large Booster for a neutrino program when not loading the storage ring • Probably cleanest best if electron and proton booster functions are separated

  46. What about eLIC? • The distance to the NuSL site is about the same for either BNL or JLab • Large Injector gets used for few minutes per fill of the collider • Rest of the time could be used for “pinging” a target • Beam power for eLIC proton injector competitive with other super beams • Implies some machine design issues • Needs 11o angle to hit NUSL • Similar ground water issues to BNL • Site is potentially restrictive but fortunately the beam line would run nearly parallel to Jefferson Ave (~10o)

  47. Reference/Links • Long baseline • T2K http://neutrino.kek.jp/jhfnu/ & hep-ex/0106019 • NOvA http://www-off-axis.fnal.gov/notes/public/pdf/offaxis0033/offaxis0033.pdf • BNL Super beam hep-ex/0305105 • CERN SPL CERN 2000-012 • Beta beam http://beta-beam.web.ch/beta-beam • Short baseline • MINERvA http://www.pas.rochester.edu/minerva/ • FINeSSE hep-ex/0402007 • APS neutrino study; super beam working group workshop two weeks ago • http://www.bnl.gov/physics/superbeam/ • Retreat and working group report this year

  48. Summary • A rich field for investigation of neutrino oscillations using long & very long baselines • Considerable beyond-SM & cosmology value • Neutrino scattering to structure • Proton injector for EIC has potential to be a world class neutrino source on a competitive time scale • Connections between NUSL, neutrino community, and EIC promise a broad program embracing different communities with orthogonal uses of the facility • A potentially powerful combination

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