Mauro Mezzetto, Istituto Nazionale Fisica Nucleare, Padova Neutrino parameters with large experiments (CP violation, mass hierarchy,...) • Present Status • Different approaches for mass hierarchy • Measuring CP: Dune and Hyper-Kamiokande • APPEC considerations
What’s missing in neutrino oscillations Neutrino mass ordering Leptonic CP violation δ CP the CP violating phase in the PMNS mixing matrix atmospheric: atmospheric: Out of the 26 (please inform Wikipedia that aren’t 19) free parameters of the Standard Model, 4 are not yet measured: m ν e , m νµ , m ντ , δ CP • To single out the three neutrino masses it’s necessary to measure the neutrino mass ordering δ CP can be detected by measuring differences between oscillation rates of • neutrinos and antineutrinos M. Mezzetto, INFN Padova, APPEC Town Meeting, Paris 2
Beyond the Standard Model • The smallnes of neutrino masses calls for extensions of the Higgs sector . An inverse mass ordering would be an intringuing hint to build such extensions. Neutrino masses are the only laboratory check of cosmological parameters . • CP violation in neutrino oscillations could be an important new ingredient to understand the matter-antimatter asymmetry in the Universe • Sterile neutrinos are by definition physics beyond the standard model • Precise measures of oscillation rates have the potential to show new physics (unitarity of the mixing matrix, NSI in neutrino oscillations, deviations from expected values of matter effects) • The large detectors necessary for MH or CP searches have great potential for non- accelerator physics: proton decay, indirect DM searches, relic SN neutrinos etc. M. Mezzetto, INFN Padova, APPEC Town Meeting, Paris 3
Short term: short baselines (sterile neutrinos) The 3 ν model is matched by 4 anomalies conspiring to the same oscillation parameters LSND: a 3.5 σ excess of ν e events in a neutrino beam created by pion decays at rest. First paper on 1995, the experiment has never been repeated. MiniBoone : a 10 years effort at Fermilab to check the LSND result at different energies (but same L/E), the final result had been inconclusive. Reactor anomaly: recent recalculation of neutrino fluxes at reactors showed an enhancement of about 3.5% of absolute fluxes with respect to previous calculations: all the reactor experiments at very short baselines could be reinterpreted as evidence of ν e disappearance (about 2.5 σ ). Recent results on reactor experiments seriously match the reliability of these recent calculations. Source calibration of Gallex and SAGE: the source calibration of these experiments showed a 15% deficit of ν e events. To be noted that the calibration had been designed and funded to check the efficiency of the detectors, while the sterile evidence is there assuming 100% efficiency of the detectors. Overall fit : the 4 anomalies can accommodated in the same oscillation model by adding a 4 th , sterile, neutrino, with a mass of about 1 eV, nevertheless tensions exist in the global fit Cosmology : severely constraints total number of neutrinos to 3 and their mass below 1 eV Most economical way to falsify steriles : a convincing null result from the source experiments at Borex (SOX) would falsify the sterile n interpretation of anomalies Most complete way to explore the phenomenology if steriles exist : the new short baseline project at Fermilab, with 3 liquid argon detectors, has the potential of fully exploit the several manifestations of sterile neutrinos.
Medium term: ν mass ordering • Pure oscillation effects in ν e disappearance: Juno • Matter effects in ν µ disappearance: INO , Hyper- Should be updated Orca and HK not Kamiokande included • Matter effects in ν e appearance: NO ν A , Dune, Hyper-Kamiokande • Resonancees of matter effects in neutrino oscillations: Orca, Pingu (Very) long baseline ν experiments have the best potential for this measurement, they set a time window for experiments with 3 σ sensitivity M. Mezzetto, INFN Padova, APPEC Town Meeting, Paris 5
ORCA and PINGU ORCA: arXiv:1601.07459; PINGU: arXiv:1401.2046 Resonant region: measure MH Saturated region: measure ∆ m 2 Dilution and systematics due to ν flux, cross-sections and angle smearing… but effect is large; Requires the identification of both ν µ and ν e (not cascade) events. M. Mezzetto, INFN Padova, APPEC Town Meeting, Paris 6
ORCA and PINGU ORCA LoI Yanez, Kouchner: Adv.High Energy Phys. 2015 (2015) 271968 PINGU LoI Performances are still preliminary • Neutrino cross sections, not known oscillation parameters and systematic errors could degrade performances (Capozzi et al, PhysRev.D.91.073011) • Evaluation of event inelasticity could improve performances (Ribordy Smirnov, PhysRevD.87.11307) NC contamination in the ν e sample to be fully • computed ORCA : Installation time 3 years, ready in 2020 if funded in 2017 PINGU : Procurement and installation takes 4 years. M. Mezzetto, INFN Padova, APPEC Town Meeting, Paris 7
JUNO CDR: arXiv:1508.07166, Physics: J.Phys. G43 (2016) no.3, 030401 • Funded, under construction • Data taking expected by 2020 • Reactors power: 36 GW (26.6 GW by 2020) • Aimed to measure MH, precision measurement of sin 2 θ 12 , δ m 2 12 , ∆ m 2 23 and also SuperNovae, solar, atmospheric, geo neutrinos, proton decay, indirect DM searches .. M. Mezzetto, INFN Padova, APPEC Town Meeting, Paris 8
JUNO As hard as to disentangle the two curves below Requires extreme control of detector response sin 2 θ 12 δ m 2 23 δ m 2 12 MH sensitivity in 6 years. External measure of ∆ m 2 µµ could be crucial M. Mezzetto, INFN Padova, APPEC Town Meeting, Paris 9
We are talking of measuring δ CP ... ... because of a very favorable combination of parameters M. Mezzetto, INFN Padova, APPEC Town Meeting, Paris 10
What we know today about δ CP T2K (Phys.Rev. D88 (2013) 3, 032002) and NO ν A (arXiv:1601.05022) measure a combination of θ 13 and δ CP while reactors (PDG 2012) measure pure θ 13 effects. Their combination favours δ CP =- π /2 M. Mezzetto, INFN Padova, APPEC Town Meeting, Paris 11
Projection of T2K+No ν a at full statistics From T2K collaboration: PTEP 2015 (2015) 4, 043C01 MH CP Full statistics of the running experiments: T2K and No ν a, equal ν and ν runs, dashed lines: including systematics M. Mezzetto, INFN Padova, APPEC Town Meeting, Paris 12
T2K-II Upgrade the beam at 1.3 MW (already approved), collect 20 10 21 pot (3 times nominal intensity) upgrade beam line, improve analysis M. Mezzetto, INFN Padova, APPEC Town Meeting, Paris 13
Good CP coverage requires order of 1 Mton x Mwatt x year M. Mezzetto, INFN Padova, APPEC Town Meeting, Paris 14
Effects of systematic errors on CP sensitivity Since a long time they are known to be the real bottleneck (or in positive the only convincing way of enhancing the experimental sensitivity) Huber, MM, Schwetz, JHEP 0803 (2008) 021 Varying luminosity at fixed θ 13 . Varying θ 13 at fixed luminosity M. Mezzetto, INFN Padova, APPEC Town Meeting, Paris 15
Systematic errors The experience of T2K A sophisticated close detector station: ND280 + Ingrid The best quality hadroproduction ν data ever produced (NA61) already included A huge, qualified, effort by the largest collaboration ever seen in neutrino physics At present limited by statistics M. Mezzetto, INFN Padova, APPEC Town Meeting, Paris 16
Two players: Dune and Hyper-Kamiokande
Two complementary approaches • HK : – short baseline →no matter effects: pure CP but reduced MH – Off axis → reduced intrinsic ν e contamination, reduced NC backgrounds • DUNE : – Long baseline → sensitive to matter effects: excellent performances in MH On axis: second oscillation maximum and sensitive to ν τ – appearance (tiny effects at 1300 km) – On axis: extended lever of arm for measurement of oscillation parameters M. Mezzetto, INFN Padova, APPEC Town Meeting, Paris 18
Hyper-Kamiokande arXiv:1109.3262, arXiv:1412.4673, PTEP 2015 (2015) 053C02 Submitted to Science Council of Japan by T. Kajita on March 31, 2016 ... with a different configuration with respect to published papers M. Mezzetto, INFN Padova, APPEC Town Meeting, Paris 19 0.75 MW 1.3 MW Beam power
Hyper-Kamiokande Assuming 2Tank HD staging (2nd tank from 7th year), 10 years total run 78% (62%) coverage at 3 σ (5 σ ) ~ 7 0 precision on δ CP possible MH sensitivity Combining beam and atmospherics Same staging assumptions M. Mezzetto, INFN Padova, APPEC Town Meeting, Paris 20
Hyper-Kamiokande M. Mezzetto, INFN Padova, APPEC Town Meeting, Paris 21
Hyper-Kamiokande M. Mezzetto, INFN Padova, APPEC Town Meeting, Paris 22
M. Mezzetto, INFN Padova, APPEC Town Meeting, Paris 23
Dune M. Mezzetto, INFN Padova, APPEC Town Meeting, Paris 24
Dune M. Mezzetto, INFN Padova, APPEC Town Meeting, Paris 25
WA105 at CERN Proto Dune Double Phase Proto Dune Single Phase M. Mezzetto, INFN Padova, APPEC Town Meeting, Paris 26
CP violation: systematic errors HK estimation assuming identical close detector as T2K Dune estimation extrapolating from Minos (no LAr close detector data so far) M. Mezzetto, INFN Padova, APPEC Town Meeting, Paris 27
CP Sensitivity Dune vs. HK ... under my own responsibility M. Mezzetto, INFN Padova, APPEC Town Meeting, Paris 28
APPEC Considerations M. Mezzetto, INFN Padova, APPEC Town Meeting, Paris 29
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