The Short-Baseline Neutrino Oscillation Program in the Fermilab Booster Neutrino Beam Neutrino Latin America Workshop - Fermilab April 27 th , 2016 Ornella Palamara Fermilab & Yale University* * on leave of absence from INFN, Laboratori Nazionali del Gran Sasso, Italy 1
U.S. future Accelerator Neutrino Physics: LAr TPC Technology ๏ The future U.S. accelerator neutrino program is based on the Liquid Argon Time Projection Chamber (LAr TPC) technology. ๏ LArTPC offers the ability to measure interactions of neutrinos and other particles in real time with sub-millimeter position resolution, allowing for ๏ track reconstruction ๏ particle identification and ๏ electron/gamma separation far beyond that offered by any other neutrino detection method. O. Palamara | SBN program at FNAL Neutrino - Latin America Workshop | April 27 2016 2
The US LAr TPC Program: a path toward DUNE A rich R&D and physics program D & R LArIAT CAPTAIN LUKE LAPD (2015) 35Ton Yale TPC and Bo (2008) (2011) LArTPC LArTPC (2013) (2008-2009) Material Teststand LAr Purity Calibration Calibration Cryostat Purity Proof of Concept SBN program, this talk SBND First&T300&in&Cleanroom&at&CERN& ICARUS-T600 Physics ArgoNeuT MicroBooNE DUNE SBN (SBND, MicroBooNE, ICARUS-T600) (2009 - 2010) (2015 - 2018) (2023+) (2018 - 2021) ν -Ar Cross Sections MiniBooNE CP Violation Searches for Low Energy Excess Sterile Neutrino Oscillations O. Palamara | SBN program at FNAL Neutrino - Latin America Workshop | April 27 2016 3
Why a Short-baseline accelerator neutrino program? Physics motivations for the FNAL Short Baseline Neutrino program (SBN) a multi‐detector, LAr TPC based facility on the - Booster Neutrino Beam - Experimental Hints For Beyond Three Neutrino Mixing m e a B e r s t o o B O. Palamara | SBN program at FNAL Neutrino - Latin America Workshop | April 27 2016 4
Short-Baseline Neutrino Anomalies (I) In recent years, two classes of experimental “neutrino anomalies” have been reported from measurement at short-baseline: (I) An apparent 𝜉 e disappearance signal in the low energy anti- neutrinos from nuclear reactors (“reactor anomaly”) and from radioactive neutrino sources in the Gallium experiments (“Gallium anomaly”) ~ 2.7σ O. Palamara | SBN program at FNAL Neutrino - Latin America Workshop | April 27 2016 5
Short-Baseline Neutrino Anomalies (II) (II) Evidence for an electron-like excess from neutrinos from particle accelerators (the “LSND and Mini-BooNE anomalies”) LSND MiniBooNE O. Palamara | SBN program at FNAL Neutrino - Latin America Workshop | April 27 2016 6
Short-Baseline Accelerator Anomalies LSND _ Baseline 30 m Low energy 𝜉 𝜈 beam from a decay-at-rest pion beam E= [20 – 50] MeV L/E ≈ 1 m/MeV 167 ¡tons ¡liquid ¡scintillator Oscillation signal? } Backgrounds _ Detected an excess in the appearance of 𝜉 e, _ _ corresponding to a 3.8 𝜏 evidence for 𝜉 𝜈 → 𝜉 e oscillation occurring at Δm 2 ≃1 eV 2 This signal cannot be accommodated with the 3 SM neutrinos! O. Palamara | SBN program at FNAL Neutrino - Latin America Workshop | April 27 2016 7
Short-Baseline Accelerator Anomalies MiniBooNE 540 m from the target E=[0 - 2] GeV L/E ≈ 1 m/MeV 800 ¡tons ¡mineral ¡oil PRL 110 (2013) 161801 LSND excess expected at HE • Decay in flight neutrino source • L/E similar to LSND • LSND anomaly not evident in MiniBooNE where expected, but a clear excess in 𝜉 𝜈 → 𝜉 e (3.4 𝜏 ) _ _ and 𝜉 𝜈 → 𝜉 e (2.8 𝜏 ) appearance is observed in a Low-energy excess lower energy range O. Palamara | SBN program at FNAL Neutrino - Latin America Workshop | April 27 2016 8
Short-Baseline Accelerator Anomalies MiniBooNE 540 m from the target E=[0 - 2] GeV L/E ≈ 1 m/MeV 800 ¡tons ¡mineral ¡oil PRL 110 (2013) 161801 MiniBooNE (Cherenkov detector) cannot distinguish electron from single gamma and cannot determine the composition of the excess – Electrons or photons? O. Palamara | SBN program at FNAL Neutrino - Latin America Workshop | April 27 2016 9
Hints at new physics None of the SBL neutrino anomalies can be described by oscillations between the three Standard Model neutrinos LSND and MiniBooNE allowed regions LSND The standard active neutrino mass Atmospheric splittings are way Atmospheric 10 -3 down here at 10 -3 Solar and 10 -5 eV 2 Solar 10 -5 O. Palamara | SBN program at FNAL Neutrino - Latin America Workshop | April 27 2016 10
Hints at new physics None of the SBL neutrino anomalies can be described by oscillations between the three Standard Model neutrinos and … Could be pointing at additional physics beyond the Standard Model in the neutrino sector: additional neutrino states with larger mass-squared differences driving neutrino oscillation at small distances 3 flavor states, 3 “active” (weakly interacting) neutrinos! Any additional neutrino doesn’t participate in weak interactions ⇒ “sterile neutrino” * * Sterile neutrinos were introduced by Pontecorvo in 1968 as neutrinos with no standard model interaction O. Palamara | SBN program at FNAL Neutrino - Latin America Workshop | April 27 2016 11
Sterile Neutrino Search at FNAL ๏ The accelerator neutrino anomalies at short-baseline hint at oscillation with very small amplitude ๏ Resolving small oscillation effects requires good control of systematic uncertainties Kopp et at. Best ➩ FNAL SBN: Multi-detector approach in a well characterized beam O. Palamara | SBN program at FNAL Neutrino - Latin America Workshop | April 27 2016 12
Fermilab – aerial view O. Palamara | SBN program at FNAL Neutrino - Latin America Workshop | April 27 2016 13
Fermilab – Neutrino beams Booster'Neutrino'Beam'(BNB)' Booster'Neutrino'Beam'(BNB)' Fermilab’s+ low2energy +neutrino+beam:++ Fermilab’s+ low(energy +neutrino+beam:++ + ⟨ E ν ⟩ +≈+700+MeV + +<E ν >+≈+700+MeV + Booster'('8'GeV'protons' Neutrino Latin America Workshop - Fermilab April 27 th , 2016 Ornella Palamara Fermilab & Yale University* * on leave of absence from INFN, Laboratori Nazionali del Gran Sasso, Italy 14
Fermilab – Neutrino beams Booster'Neutrino'Beam'(BNB)' Booster'Neutrino'Beam'(BNB)' Fermilab’s+ low2energy +neutrino+beam:++ Fermilab’s+ low(energy +neutrino+beam:++ + ⟨ E ν ⟩ +≈+700+MeV + +<E ν >+≈+700+MeV + Booster'('8'GeV'protons' Small electron neutrino contamination: <0.5% • Beam of mostly muon neutrinos • Search for flavor 𝜉 𝜈 disappearance and 𝜉 e appearance • BNB stably running for a decade Neutrino Latin America Workshop - Fermilab (well characterized) April 27 th , 2016 • Anomalies exist here (MiniBooNE) Ornella Palamara Fermilab & Yale University* * on leave of absence from INFN, Laboratori Nazionali del Gran Sasso, Italy 15
MicroBooNE: testing an anomaly Detector commissioning Summer 2015 470 m, 86 t Neutrino run started on Oct. 15 ICARUS-T600 MICROBOONE m a B e e r s t o o B SBN program - Phase 1 - The MicroBooNE detector is taking neutrino data • Apply the LArTPC technology to test the unexplained excess in the MiniBooNE data (on the same beam) • Determine its composition as electrons (from 𝜉 e appearance) or photons (from unaccounted background) . O. Palamara | SBN program at FNAL Neutrino - Latin America Workshop | April 27 2016 16
FNAL Short Baseline Neutrino program arXiv:1503.01520, January 2014 110 m, 112 t 600 m, 470 t 470 m, 86 t ICARUS-T600 MicroBooNE SBND m a B e r t e o s B o SBN program - Phase 2 - By 2018, the MicroBooNE detector will be joined by two additional LAr-TPC detectors at different baselines • the SBND detector and • the ICARUS-T600 detector forming a LAr TPC trio (to sample the neutrino spectrum as a function distance) for the SBN neutrino oscillation program O. Palamara | SBN program at FNAL Neutrino - Latin America Workshop | April 27 2016
SBND - closest to the source 110 m, 112 ton SBND 1 Neutrino Energy: 700 MeV Oscillation Probability [%] 2 2 m = 1.2 eV ∆ 41 0.8 m a B e r t e o s B o 2 sin (2 ) = 0.003 θ 0.6 The Short-Baseline Near Detector (SBND), which will sit close to the source, plays a MicroBooNE 0.4 ICARUS unique role in the chain of detectors, SBND measuring the purity of the muon neutrino 0.2 beam (it will characterize the beam before oscillations occur and address one of the dominant systematic uncertainties) 0 200 400 600 800 Length of Neutrino Flight [m] O. Palamara | SBN program at FNAL Neutrino - Latin America Workshop | April 27 2016 18
ICARUS - high-tech from Italy 600 m, 470 t ICARUS-T600 m a B e r t e o s B o ๏ The ICARUS T600 neutrino detector —the world’s largest liquid-argon neutrino experiment — operated at Gran Sasso National Laboratory in Italy for four years on the CNGS beam, will make its way across the ocean for a new research at Fermilab. ๏ Given its large mass and far location ICARUS-T600 will provide high sensitivity to oscillated neutrinos allowing for a precision search. O. Palamara | SBN program at FNAL Neutrino - Latin America Workshop | April 27 2016 19
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