Observation of a Significant Excess of Electron-Like Events3

1. MiniBooNE 2. Beam Observation of a Significant Excess of Electron-Like Events3. Detector 4. Oscillation in the MiniBooNE Short-Baseline Neutrino Experiment5. Discussion

PRL121(2018)221801 outline 1. MiniBooNE neutrino experiment 2. Booster Neutrino Beamline (BNB) 3. MiniBooNE detector 4. Oscillation candidate search 5. Discussion

Teppei Katori for the MiniBooNE collaboration Queen Mary University of London Physics Colloquium DESY, Zeuthen, Germany, April 24, 2019 Teppei Katori, [email protected] 24/04/19 1 1. MiniBooNE 2. Beam 3. Detector 4. Oscillation 5. Discussion 1. MiniBooNE neutrino experiment

2. Booster Neutrino Beamline (BNB)

3. MiniBooNE detector

4. Oscillation candidate search

5. Discussion

Teppei Katori, [email protected] 24/04/19 2 1. MiniBooNE 2. Beam 3. Detector 4. Oscillation 5. Discussion

Teppei Katori, [email protected] 24/04/19 3 1. MiniBooNE 2. Beam 3. Detector 4. Oscillation 5. Discussion

The most visible particle physics result of the year 2018

Teppei Katori, [email protected] 24/04/19 4 https://physics.aps.org/articles/v11/122 LSND, PRD64(2002)112007 1. MiniBooNE � 2. Beam � � ⟶ � = ��2�� 1.27Δ� 3. Detector 1. LSND experiment 4. Oscillation � 5. Discussion LSND experiment at Los Alamos observed excess of anti-electron neutrino events in the anti-muon oscillation + n µ ¾¾¾¾®n e + p ® e + n neutrino beam. n + p ® d + g 87.9 ± 22.4 ± 6.0 (3.8.s) L/E~30m/30MeV~1 LSND signal

+ + p ®n µ + µ + + µ ® e +n e +n µ

Teppei Katori, [email protected] 24/04/19 5 LSND, PRD64(2002)112007 1. MiniBooNE � 2. Beam � � ⟶ � = ��2�� 1.27Δ� 3. Detector 1. LSND experiment 4. Oscillation � 5. Discussion

3 types of neutrino oscillations are found:

LSND neutrino oscillation: Dm2~1eV2 Atmospheric neutrino oscillation: Dm2~10-3eV2 Solar neutrino oscillation : Dm2~10-5eV2

But we cannot have so many Dm2!

2 2 2 Dm13 ≠ Dm12 + Dm23

ns nt nµ ne

LSND signal indicates 4th generation neutrino, but we know there is no additional flavour from Z-boson decay, so it must be sterile neutrino MiniBooNE is designed to have same L/E~500m/500MeV~1 to test LSND Dm2~1eV2

Teppei Katori, [email protected] 24/04/19 6 1. MiniBooNE � 2. Beam � � ⟶ � = ��2�� 1.27Δ� 3. Detector 1. MiniBooNE experiment 4. Oscillation � 5. Discussion Keep L/E same with LSND, while changing systematics, energy & event signature;

MiniBooNE is looking for the single isolated electron like events, which is the signature of ne events

oscillation − νµ    → νe + n → p + e oscillation p n e+ ν µ    → νe + → + FNAL Booster target and horn decay region absorber dirt detector

€ K+ p+ ??? Booster nµ ® ne

primary beam secondary beam tertiary beam (protons) (mesons) (neutrinos) MiniBooNE has; - higher energy (~500 MeV) than LSND (~30 MeV) - longer baseline (~500 m) than LSND (~30 m)

Teppei Katori, [email protected] 24/04/19 7 1. MiniBooNE 2. Beam 3. Detector 1. Easter Eggs of MiniBooNE 1 – Recent publications 4. Oscillation 5. Discussion

PHYSICAL REVIEW LETTERS 120, 141802 (2018)

signature of dark matter annihilation in the Sun [5,6]. PRL120(2018)141802 Despite the importance of the KDAR neutrino, it has never MiniBooNE

been isolated and identified. 86 m In the charged current (CC) interaction of a 236 MeV νμ background KDAR 12 − NuMI (νμ C → μ X), the muon kinetic energy (Tμ) and closely beam decay pipe related neutrino-nucleus energy transfer (ω E − E ) horns ν μ target distributions are of particular interest for benchmarking¼ absorber neutrino interaction models and generators, which report widely varying predictions for kinematics at these tran- 5 m 675 m sition-region energies [7–14]. Traditionally, experiments 40 m are only sensitive, at best, to total visible hadronic energy FIG. 1. The NuMI beamline and various sources of neutrinos since invisible neutrons and model-dependent nucleon that reach MiniBooNE (dashed lines). The signal KDAR neu- removal energy corrections prevent the complete trinos (solid line) originate mainly from the absorber. reconstruction of energy transfer [16]. The measurements reported here, therefore, provide a unique look at muon kinematics and the relationship to neutrino energy in the antineutrino modes, since KDAR production from the few hundreds of MeV range, highly relevant for both absorber is not dependent on the polarization of the horns. elucidating the neutrino-nucleus interaction and performing However, the background νμ and ν¯μ event rate is predicted low energy precision oscillation measurements at short to be about 30% lower in the antineutrino mode. We use data taken in this configuration from 2009–2011, corre- [17–19] and long baselines [20]. 20 The MiniBooNE detector uses 445 tons (fiducial volume) sponding to 2.62 × 10 protons on the NuMI target. of mineral oil and 1280 photomultiplier tubes (PMTs), with The focus of this analysis is on reconstructing KDAR- an additional 240 PMTs instrumenting a veto region, to like low energy νμ CC events. A simple detector observ- identify neutrino events originating from the Booster able, PMThits5ns, defined as the number of PMT hits Neutrino Beamline (BNB) and Neutrinos at the Main multiplied by the fraction of light detected in the first 5 ns Injector (NuMI) neutrino sources. The experiment has after correcting for vertex position, is used to reconstruct Tμ reported numerous oscillation and cross section measure- in selected events featuring (1) an electron from muon − ments and new physics searches since data taking began in decay, noting that about 7.8%PRL118(2017)221803 of μ capture on nuclei [26], (2) a lack of veto activity, and (3) a reconstructed distance 2002 [17]. For this analysis, we considerTeppei the Katori, charge [email protected] and time 24/04/19PRD98(2018)1120048 data of PMT hits collected during the NuMI beam spill. NuMI between the end point of the primary track and the muon provides an intense source of KDAR neutrinos at MiniBooNE decay vertex of < 150 cm. This detector observable is in a somewhat indirect way. The 96 cm, 2.0 interaction length meant to isolate the muon via its characteristic prompt NuMI target allows about 1=6 of the primary NuMI protons Čerenkov light, as compared to the delayed scintillation- (120 GeV) to pass through to the beam absorber [21], 725 m only light (τ 18 ns) from the below-threshold hadronic ¼ downstream of the target and 86 m from the center of part of the interaction. According to the NUWRO neutrino MiniBooNE. The aluminum-core absorber, surrounded by event generator [12], only 14% of muons created in concrete and steel, is nominally meant to stop the remnant 236 MeV νμ CC events are expected to be produced with hadrons, electrons, muons, and gammas that reach the end of energy less than 39 MeV, the Čerenkov threshold for the decay pipe. Interactions of primary protons with the muons in MiniBooNE mineral oil. KDAR-induced muons absorber provide about 84% of the total KDAR neutrinos are expected to populate a “signal region,” defined as from NuMI that reach MiniBooNE. Predictions from FLUKA 0–120 PMThits5ns and representing Tμ in the range [22,23], MARS [24],andGEANT4 [25] for kaon production at 0–115 MeV. Because of the kinematics of 236 MeV νμ the absorber vary significantly, from 0.06–0.12 KDAR CC events, no signal is expected elsewhere, which is con- νμ/proton on target. The background to the KDAR signal, sidered the “background-only region” (>120 PMThits5ns). νμ and ν¯μ CC events which produce a muon in the 0–115 MeV Although the signal muon energy range considered for this range, originates mainly from pion and kaon decay in flight measurement is lower than past MiniBooNE cross section near the target station and in the upstream-most decay pipe. analyses featuring νμ=ν¯μ [27–33], the energy and timing The non-KDAR νμ and ν¯μ flux from the absorber, dominated distributions of MiniBooNE’s vast calibration sample of by decay-in-flight kaons (Kμ3 and Kμ2) with a comparatively 0–53 MeV electrons from muon decay provide a strong small charged pion component, is expected to contribute at benchmark for understanding the detector’s response to the few-percent level based on a GEANT4 simulation of the low energy muons in terms of both scintillation and beamline. Figure 1 shows a schematic of the NuMI beamline Čerenkov light. Further, a scintillator “calibration cube” in and its relationship to MiniBooNE. the MiniBooNE volume at a 31 cm depth, used to form a very The KDAR event rate at MiniBooNE is expected to be pure sample of tagged 95 4 MeV cosmic ray muons, similar in both NuMI’s low-energy neutrino and shows excellent agreement betweenÆ data and Monte Carlo

141802-2 1. MiniBooNE 2. Beam 3. Detector 1. Easter Eggs of MiniBooNE 2 – Tools 4. Oscillation 5. Discussion fitQun: MiniBooNE: NIMA608(2009)206 Likelihood-based Cherenkov ring Flux systematic error: MiniBooNE: PRD79(2009)072002 fitter, the main reconstruction - Errors are derived directly from hadron production used by Super-Kamiokande data (spline fit), not based on any flux model. (LSNDàMiniBooNEàSuperK). - Neutrino flux error = hadron production data error

Sanford-Wang fit error data error

Online remote shift: - <1 event per minute - MiniBooNE is the first remote shift experiment at Fermilab - All neutrino experiments at Fermilab adapted online remote shift, including NOvA, MicroBooNE, MINERvA, etc

Teppei Katori, [email protected] 24/04/19 9 1. MiniBooNE 2. Beam 3. Detector 1. Easter Eggs of MiniBooNE 3 – Offspring 4. Oscillation 5. Discussion

Argonne: Zelimir MSU: Kendall Djurcic (PD) Mahn (PhD) Lancaster: Jarek Nowak (PD) Fermilab: Chicago: Dave Yale: Bonnie Jen Raaf (PhD) Schmitz (PhD) Fleming (PD) Fernanda Garcia (PD) Zarko Pavlovic (PD) Royal Holloway: Chris Polly (PD) Jocelyn Monroe (PhD) Sam Zeller (PD) Columbia: Georgia Karagiorgi (PhD) Queen Mary: IHEP: Jun Teppei Katori (PhD) Cao (PD) SLAC: Hiro Tanaka (PD) Stony Brook: Mike Shanghai Jiao Tong U: Wilking (PhD) Imperial: Morgan Haijun Yang (PD) Caltech: Ryan Wascko (PD) Patterson (PhD) Pittsburgh: Brian Batell (PD) IFIC: Michel NMSU: Robert Sorel (PhD) Cooper (PD) Virginia Tech: Jon Link (PD) Colorado: Eric Zimmerman (PD) LSU: Martin Florida: Heather Tzanov (PD) Ray (PD) UNAM: Alexis Aguilar Arevalo (PhD)

…and more are coming!

Teppei Katori, [email protected] 24/04/19 10 1. MiniBooNE 2. Beam 3. Detector 1. Easter Eggs of MiniBooNE 4 – #WomenInSTEM 4. Oscillation 5. Discussion

Argonne: Zelimir MSU: Kendall Djurcic (PD) Mahn (PhD) Lancaster: Jarek Nowak (PD) Fermilab: Chicago: Dave Yale: Bonnie Jen Raaf (PhD) Schmitz (PhD) Fleming (PD) Fernanda Garcia (PD) Zarko Pavlovic (PD) Royal Holloway: Chris Polly (PD) Jocelyn Monroe (PhD) Sam Zeller (PD) Columbia: Georgia Karagiorgi (PhD) Queen Mary: IHEP: Jun Teppei Katori (PhD) Cao (PD) SLAC: Hiro Tanaka (PD) Stony Brook: Mike Shanghai Jiao Tong U: Wilking (PhD) Imperial: Morgan Haijun Yang (PD) Caltech: Ryan Wascko (PD) Patterson (PhD) Pittsburgh: Brian Batell (PD) IFIC: Michel NMSU: Robert Sorel (PhD) Cooper (PD) Virginia Tech: Jon Link (PD) Colorado: Eric Zimmerman (PD) LSU: Martin Florida: Heather Kendall Mahn Tzanov (PD) Ray (PD) Jocelyn Monroe (MSU) (Royal Holloway) UNAM: Alexis Aguilar Arevalo (PhD)

…and more are coming!

Georgia Karagiorgi Janet Conrad Sam Zeller Jen Raaf Fernanda GarciaTeppei Katori,Heather [email protected] Ray Bonnie Fleming 24/04/19 11 (Columbia) (MIT) (Fermilab) (Fermilab) (Fermilab) (Florida) (Yale) MiniBooNE: PRD81(2010)092005 1. MiniBooNE Martini et al,PRC80(2009)065501 2. Beam 3. Detector 1. Easter Eggs of MiniBooNE 5 – Cross Sections 4. Oscillation 5. Discussion

MiniBooNE made the first detailed study of neutrino-nucleus cross sections around 1 GeV. ν µ CCQE puzzle µ 1. low Q2 suppression à Low forward efficiency? (detector?) W 2 2. high Q enhancement à Axial mass > 1.0 GeV? (physics?) p 3. large normalization à Beam simulation is wrong? (flux?) n charged-current quasi- elastic€ scattering (CCQE) CCQE interaction on nuclear targets are precisely measured€ by electron scattering - Lepton universality = precise prediction for neutrino CCQE cross-section...?€

12 € MiniBooNE vs. NOMAD nµCCQE cross section€ on C target (per nucleon)

Carbon cross section per nucleon is larger than single nucleon cross section?!

En (GeV)

Teppei Katori, [email protected] 24/04/19 12 MiniBooNE: PRD81(2010)092005 1. MiniBooNE Martini et al,PRC80(2009)065501 2. Beam 3. Detector 1. Easter Eggs of MiniBooNE 5 – Cross Sections 4. Oscillation 5. Discussion

MiniBooNE made the first detailed study of neutrino-nucleus cross sections around 1 GeV. Flux-integrated differential cross section: A new concept to measure, and report neutrino cross section data. Now the standard of the community. Slide from Martini

Discovery of nucleon correlation in neutrino scattering: - Significant enhancement of cross section (10-30%) - modify lepton kinematics and final state hadrons - the hottest topic for T2K, MINERvA, MicroBooNE, etc Particle Data Group - Section 42, “Monte Carlo Neutrino Generators” (Hugh Gallagher, Yoshinari Hayato) - Section 50, “Neutrino Cross-Section Measurements” (Sam Zeller)

On going effort from MiniBooE initiative! The first textbook of neutrino interaction physics! “Foundation of Nuclear and Particle Physics” Teppei Katori,- Cambridge [email protected] University Press (2017), ISBN:24/04/190521765110 13 - Authors: Donnelly, Formaggio, Holstein, Milner, Surrow 1. MiniBooNE 2. Beam 3. Detector 4. Oscillation 5. Discussion 1. MiniBooNE neutrino experiment

2. Booster Neutrino Beamline (BNB)

3. MiniBooNE detector

4. Oscillation candidate search

5. Discussion

Teppei Katori, [email protected] 24/04/19 14 MiniBooNE, PRD79(2009)072002 1. MiniBooNE 2. Beam 3. Detector 2. Fermilab Booster 4. Oscillation 5. Discussion

MiniBooNE extracts beam from the 8 GeV Booster FNAL Booster

Booster Target Hall

FNAL Booster target and horn decay region absorber dirt detector

K+ p+ ??? Booster nµ ® ne

primary beam secondary beam tertiary beam (protons) (mesons) (neutrinos)

Teppei Katori, [email protected] 24/04/19 15 MiniBooNE, PRD79(2009)072002 1. MiniBooNE 2. Beam 3. Detector 2. Fermilab Booster 4. Oscillation 5. Discussion

MiniBooNE extracts beam from the 8 GeV Booster FNAL Booster

Booster Target Hall

FNAL Booster target and horn decay region absorber1.5ns dirt x82detector …... 19ns

K+ Beam bunch structure p+ ??? Booster nµ ® ne 1.6µs x5 /1sec primary beam secondary beam tertiary beam 20µs (trigger) (protons) (mesons) (neutrinos) Beam spill structure Teppei Katori, [email protected] 24/04/19 16 MiniBooNE, PRD79(2009)072002 1. MiniBooNE 2. Beam 3. Detector 2. Magnetic Focusing Horn 4. Oscillation 5. Discussion Magnetic focusing horn 8GeV protons are delivered to a 1.7 l Be target

within a magnetic horn (2.5 kV, 174 kA) that increases the flux by ´ 6

By switching the current direction, the horn can focus either positive (neutrino mode) or negative (antineutrino mode) mesons.

FNAL Booster target and horn decay region absorber dirt detector

p- p+

K+ p+ ??? Booster nµ ® ne p+ p-

primary beam secondary beam tertiary beam (protons) (mesons) (neutrinos)

Teppei Katori, [email protected] 24/04/19 17 MiniBooNE, PRD79(2009)072002 1. MiniBooNE HARP, Eur.Phys.J.C52(2007)29 2. Beam 3. Detector 2. Hadron Production 4. Oscillation 5. Discussion

HARP experiment (CERN) Modeling of meson production is based on the measurement done by HARP collaboration. - Identical, but 5% l Beryllium target - 8.9 GeV/c proton beam momentum - >80% coverage for p+

FNAL Booster target and horn decay region absorber dirt detector

K+ p+ ??? Booster nµ ® ne

primary beam secondary beam tertiary beam (protons) (mesons) (neutrinos)

Teppei Katori, [email protected] 24/04/19 18 MiniBooNE, PRD79(2009)072002 1. MiniBooNE HARP, Eur.Phys.J.C52(2007)29 2. Beam 3. Detector 2. Hadron Production 4. Oscillation 5. Discussion

HARP kinematic coverage FNAL Booster target and horn decay region absorber dirt detector

K+ p+ ??? Booster nµ ® ne

primary beam secondary beam tertiary beam (protons) (mesons) (neutrinos)

Teppei Katori, [email protected] 24/04/19 19 MiniBooNE, PRD79(2009)072002 1. MiniBooNE 2. Beam 3. Detector 2. Booster Neutrino Beamline (BNB) 4. Oscillation 5. Discussion Neutrino flux from simulation by GEANT4 p ® µ nµ

MiniBooNE is the ne (anti ne) appearance oscillation experiment, so we need to know the distribution of beam origin ne and anti ne (intrinsic ne) K® µ nµ neutrino mode antineutrino mode intrinsic ne 0.6% 0.6% contamination

intrinsic ne from µ decay 49% 55%

µ ® e nµ ne intrinsic ne from K decay 47% 41% others 4% 4% K® p e ne wrong sign fraction 6% 16% FNAL Booster target and horn decay region absorber dirt detector

K+ p+ ??? Booster nµ ® ne

primary beam secondary beam tertiary beam (protons) (mesons) (neutrinos) 20 Teppei Katori, [email protected] 24/04/19 Huang, Neutrino 2018 1. MiniBooNE 2. Beam 3. Detector 2. BNB status 4. Oscillation 5. Discussion

Teppei Katori, [email protected] 24/04/19 21 1. MiniBooNE 2. Beam 3. Detector 4. Oscillation 5. Discussion 1. MiniBooNE neutrino experiment

2. Booster Neutrino Beamline (BNB)

3. MiniBooNE detector

4. Oscillation candidate search

5. Discussion

Teppei Katori, [email protected] 24/04/19 22 MiniBooNE,NIM.A599(2009)28 1. MiniBooNE 2. Beam 3. Detector 4. Oscillation 3. Events in the Detector 5. Discussion

The MiniBooNE Detector - 541 meters downstream of target - 12 meter diameter sphere (10 meter “fiducial” volume)

- Filled with 800 t of pure mineral oil (CH2) Booster (Fiducial volume: 450 t) - 1280 inner phototubes, - 240 veto phototubes

Teppei Katori, [email protected] 24/04/19 23 MiniBooNE,NIM.A599(2009)28 1. MiniBooNE 2. Beam 3. Detector 4. Oscillation 3. Events in the Detector 5. Discussion

The MiniBooNE Detector - 541 meters downstream of target - 12 meter diameter sphere (10 meter “fiducial” volume)

- Filled with 800 t of pure mineral oil (CH2) (Fiducial volume: 450 t) - 1280 inner phototubes, - 240 veto phototubes

Teppei Katori, [email protected] 24/04/19 24 MiniBooNE,NIM.A599(2009)28 1. MiniBooNE 2. Beam 3. Detector 4. Oscillation 3. Events in the Detector 5. Discussion

The MiniBooNE Detector - 541 meters downstream of target - 12 meter diameter sphere (10 meter “fiducial” volume)

- Filled with 800 t of pure mineral oil (CH2) (Fiducial volume: 450 t) - 1280 inner phototubes, - 240 veto phototubes

Teppei Katori, [email protected] 24/04/19 25 MiniBooNE,NIM.A599(2009)28 1. MiniBooNE 2. Beam 3. Detector 4. Oscillation 3. Events in the Detector 5. Discussion

Times of hit-clusters (subevents) Beam spill (1.6µs) is clearly evident Beam and simple cuts eliminate cosmic Cosmic BG backgrounds

Neutrino Candidate Cuts <6 veto PMT hits Gets rid of muons

>200 tank PMT hits Gets rid of Michels

Only neutrinos are left!

Teppei Katori, [email protected] 24/04/19 26 MiniBooNE,NIM.A599(2009)28 1. MiniBooNE 2. Beam 3. Detector 4. Oscillation 3. Events in the Detector 5. Discussion

Times of hit-clusters (subevents) Beam spill (1.6µs) is clearly evident Beam and simple cuts eliminate cosmic Michels backgrounds

Neutrino Candidate Cuts <6 veto PMT hits Gets rid of muons

>200 tank PMT hits Gets rid of Michels

Only neutrinos are left!

Teppei Katori, [email protected] 24/04/19 27 MiniBooNE,NIM.A599(2009)28 1. MiniBooNE 2. Beam 3. Detector 4. Oscillation 3. Events in the Detector 5. Discussion

Times of hit-clusters (subevents) Beam spill (1.6µs) is clearly evident Beam simple cuts eliminate cosmic Only backgrounds

Neutrino Candidate Cuts <6 veto PMT hits Gets rid of muons

>200 tank PMT hits Gets rid of Michels

Only neutrinos are left!

Teppei Katori, [email protected] 24/04/19 28 MiniBooNE collaboration, 3. Events in the Detector NIM.A599(2009)28 Muons - Long strait tracks à Sharp clear rings

Electrons - Multiple scattering - Radiative processes à Scattered fuzzy rings

Neutral pions - Decays to 2 photons à Double fuzzy rings

NC elastic scattering - No Cherenkov radiation

à24/04/19Isotropic scintillation hitsTeppei Katori, [email protected] 29 MiniBooNE collaboration, 3. Events in the Detector NIM.A599(2009)28 Muons - Long strait tracks à Sharp clear rings

Electrons - Multiple scattering - Radiative processes à Scattered fuzzy rings

Neutral pions - Decays to 2 photons à Double fuzzy rings

NC elastic scattering - No Cherenkov radiation

à24/04/19Isotropic scintillation hitsTeppei Katori, [email protected] 30 MiniBooNE collaboration, 3. Events in the Detector NIM.A599(2009)28 Muons - Long strait tracks à Sharp clear rings

Electrons - Multiple scattering - Radiative processes à Scattered fuzzy rings

Neutral pions - Decays to 2 photons à Double fuzzy rings

NC elastic scattering - No Cherenkov radiation

à24/04/19Isotropic scintillation hitsTeppei Katori, [email protected] 31 MiniBooNE collaboration, 3. Events in the Detector NIM.A599(2009)28 Muons - Long strait tracks à Sharp clear rings

Electrons - Multiple scattering - Radiative processes à Scattered fuzzy rings

Neutral pions - Decays to 2 photons à Double fuzzy rings

NC elastic scattering - No Cherenkov radiation

à24/04/19Isotropic scintillation hitsTeppei Katori, [email protected] 32 MiniBooNE: PRL100(2008)032301 1. MiniBooNE 2. Beam 3. Detector 3. QE kinematics based energy reconstruction 4. Oscillation 5. Discussion

Event reconstruction from Cherenkov ring profile for PID - scattering angle q and kinetic energy of charged lepton T are measured

Charged Current Quasi-Elastic (CCQE) interaction The simplest and the most abundant interaction around ~1 GeV. Neutrino energy is reconstructed from the observed lepton kinematics “QE assumption” 1. assuming neutron at rest � � 2. assuming interaction is CCQE � + � ⟶ � + � (� + � ⟶ � + � ) � X T � µ µ � n -beam cosq �� − 0.5� � = n � − � + �� p CCQE is the most important channel of neutrino oscillation physics for MiniBooNE, T2K, microBoonE, SBND, etc (also important for NOvA, Hyper-Kamiokande, DUNE, etc)

Teppei Katori, [email protected] 24/04/19 33 1. MiniBooNE 2. Beam 3. Detector 3. Detector stability 4. Oscillation 5. Discussion Event rate look consistent from expectations - Antineutrino mode (factor 5 lower event rate) - factor ~2 lower flux - factor ~2-3 lower cross section - Dark matter mode (factor 50 lower event rate) MiniBooNE, PRL118(2017)221803, - factor ~40 lower flux PRD98(2018)112004

“Old” data set “New” data set

34 Teppei Katori, [email protected] 24/04/19 1. MiniBooNE 2. Beam 3. Detector 3. Detector stability 4. Oscillation 5. Discussion Old and new data agree within 2% over 8 years separation.

Michel electron spectrum peak 38

32 All Mean E (MeV) 30

26 01 04 12 05 01 08 12 09 01 12 12 13 01 16

0.05 0 -0.05 -0.1 -0.15 -0.2 -0.25 Fractional deviation from average 01 04 12 05 01 08 12 09 01 12 12 13 01 16 35 Teppei Katori, [email protected] 24/04/19 1. MiniBooNE 2. Beam 3. Detector 3. Detector stability 4. Oscillation 5. Discussion Old and new data agree within 2% over 8 years separation.

EnQE from nµCCQE sample po mass peak from NCpo sample

36 Teppei Katori, [email protected] 24/04/19 1. MiniBooNE 2. Beam 3. Detector 3. Data-Simulation comparison 4. Oscillation 5. Discussion Old and new data agree within 2% over 8 years separation. - Excellent agreements with MC. EnQE from nµCCQE sample po mass peak from NCpo sample

37 Teppei Katori, [email protected] 24/04/19 1. MiniBooNE 2. Beam 3. Detector 4. Oscillation 5. Discussion 1. MiniBooNE neutrino experiment

2. Booster Neutrino Beamline (BNB)

3. MiniBooNE detector

4. Oscillation candidate search

5. Discussion

Teppei Katori, [email protected] 24/04/19 38 1. MiniBooNE 2. Beam 3. Detector 4. Internal background constraints 4. Oscillation misID 5. Discussion

All backgrounds are internally constrained à intrinsic (beam ne) = flat à misID (gamma) = accumulate at low E intrinsic

39 Teppei Katori, [email protected] 24/04/19 1. MiniBooNE 2. Beam 3. Detector 4. from -decay constraint 4. Oscillation ne µ 5. Discussion

All backgrounds are internally constrained à intrinsic (beam ne) = flat à misID (gamma) = accumulate at low E

ne from µ decay is constrained from nµCCQE measurement

40 Teppei Katori, [email protected] 24/04/19 1. MiniBooNE 2. Beam 3. Detector 4. from -decay constraint 4. Oscillation ne µ 5. Discussion

They are large background, but we have a good control of �&�̅ background by joint �&�(�̅ &�̅ ) fit for oscillation search.

p ® µ nµ

� ⟶ � + � measured � ⟶ � + �̅ guessed

� ⟶ � + �̅ + � � ⟶ � + � + �̅ µ ® e nµ ne

41 Teppei Katori, [email protected] 24/04/19 MiniBooNE, PRD84(2011)072005 1. MiniBooNE 2. Beam 3. Detector 4. Anti-neutrino mode flux tuning 4. Oscillation 5. Discussion

�̅ &�̅ flux are harder to predict due to larger wrong sign (�&�) background, and measured lepton kinematics and p+ production are used to tune flux à they consistently suggest we overestimate antineutrino flux around 20%

Michel electron counting is sensitive to � contamination in �̅ beam

42 Teppei Katori, [email protected] 24/04/19 1. MiniBooNE 2. Beam 3. Detector 4. from K+-decay constraint 4. Oscillation ne 5. Discussion

All backgrounds are internally constrained à intrinsic (beam ne) = flat à misID (gamma) = accumulate at low E

ne from µ decay is constrained from nµCCQE measurement

ne from K decay is constrained from SciBooNE high energy nµ event measurement

43 Teppei Katori, [email protected] 24/04/19 SciBooNE,PRD84(2011)012009 1. MiniBooNE 2. Beam 3. Detector 4. from K+-decay constraint 4. Oscillation ne 5. Discussion

SciBooNE is a scintillator tracker located on BNB (detector hall is used by ANNIE now) - neutrinos from kaon decay tend to be higher energy, and tend to make 3 tracks - from 3 track analysis, kaon decay neutrinos are constrained (0.85±0.11, prior is 40% error)

SciBooNE 3 track event

SciBooNE,PRD84(2011)012009

44 Teppei Katori, [email protected] 24/04/19 1. MiniBooNE 2. Beam 3. Detector 4. from K+-decay constraint 4. Oscillation ne 5. Discussion

All backgrounds are internally constrained à intrinsic (beam ne) = flat à misID (gamma) = accumulate at low E

Asymmetric po decay is constrained ne from µ decay from measured is constrained NCpo rate (po®g) from nµCCQE measurement

ne from K decay is constrained from SciBooNE high energy nµ event measurement

45 Teppei Katori, [email protected] 24/04/19 MiniBooNE, PLB664(2008)41 1. MiniBooNE 2. Beam 3. Detector 4. g from po constraint 4. Oscillation po momentum data-MC comparison 5. Discussion poàgg - not background, we can measure poàg - misID background, we cannot measure

The biggest systematics is production rate of po, because once you find that, the chance to make a single gamma ray is predictable.

We measure po production rate, and o correct simulation3 with function of 3 ´10 p ´10 3 3 ´10 momentum 22 ´10 (a) 22 (a) Data Data Events Events Events 20 Events 20 3.5 +/- 3.5 +/- Asymmetric n e from µ n from µ +/- e 18 n from K +/- e 2-gamma-ray 18 0 3 n from K decay n from K e 16 e 0 3 p0 misid opening angle (b)n from K 16 e o 14 D® Ng 2.5 p0 misid p (b) dirt 12 14 D® Ng 2.5 o other 2 p 10 dirt 121.5 8 other 2 NCpo 6 101 4 1.5 event 0.58 2 MiniBooNE, 0 60 -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1 -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1 1 cosq cosq PLB664(2008)41 46 g 1g 2 Teppeig 1g 2 Katori, [email protected] 24/04/19 4

3 3 0.5 ´10 ´10 2.2 2

Events Events 1.8 2 0 0 -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1 -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1 1.8 1.6 cosq cosq g 1g 2 g 1g 2 1.6 (c) 1.4 (d) 1.4 3 3 1.2 ´10 ´10 1.2 2.21 1

Events 0.82 Events 1.8 0.8 0.6 0.6 1.8 1.6 0.4 0.4 1.6 1.4 0.2 0.2 (c) (d)

0 1.40 -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1 -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1 1.2 cosq cosq g 1g 2 g 1g 2 1.2 1 1 0.8 0.8 0.6 0.6 0.4 0.4

0.2 0.2

0 0 -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1 -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1 cosq cosq g 1g 2 g 1g 2 1. MiniBooNE 2. Beam 3. Detector 4. NC constraint 4. Oscillation g 5. Discussion

All backgrounds are internally constrained à intrinsic (beam ne) = flat à misID (gamma) = accumulate at low E

Asymmetric po decay is constrained ne from µ decay from measured is constrained NCpo rate (po®g) from nµCCQE measurement D resonance rate is constrained

from measured ne from K decay is NCpo rate constrained from SciBooNE high energy nµ event measurement

47 Teppei Katori, [email protected] 24/04/19 1. MiniBooNE 2. Beam 3. Detector 4. NC constraint 4. Oscillation g 5. Discussion

All backgrounds are internally constrained à intrinsic (beam ne) = flat à misID (gamma) = accumulate at low E

�(∆→ ��) 3Γ = �(Δ → �� ) 2Γ� Asymmetric po Gg/Gp: NCg to NCp branching ratio po fraction (=2/3) decay is constrained n from µ decay e: p escaping factor e from measured is constrained NCpo rate (po®g) This simple estimation more or less from nµCCQE agree with modern calculations (later) measurement D resonance rate is constrained

from measured ne from K decay is NCpo rate constrained from SciBooNE high energy nµ event measurement

48 Teppei Katori, [email protected] 24/04/19 1. MiniBooNE 2. Beam 3. Detector 4. External constraint 4. Oscillation g 5. Discussion

All backgrounds are internally constrained à intrinsic (beam ne) = flat à misID (gamma) = accumulate at low E

Asymmetric po decay is constrained ne from µ decay from measured is constrained NCpo rate (po®g) from nµCCQE measurement D resonance rate is constrained

from measured ne from K decay is NCpo rate constrained from SciBooNE high dirt rate is energy nµ event measured from measurement dirt data sample

49 Teppei Katori, [email protected] 24/04/19 MiniBooNE, PRD82(2010)092005 1. MiniBooNE 2. Beam 3. Detector 4. External constraint 4. Oscillation g 5. Discussion

MiniBooNE detector has a simple geometry - Spherical Cherenkov detector - Homogeneous, large active veto We have number of internal measurement to understand distributions of external events.

e.g.) NC elastic candidates with function of Z Mis-modelling of external background is visible

After tuning Before tuning Internal events External events

50 Teppei Katori, [email protected] 24/04/19 1. MiniBooNE 2. Beam 3. Detector 4. Internal background constraints 4. Oscillation 5. Discussion

All backgrounds are internally constrained à intrinsic (beam ne) = flat à misID (gamma) = accumulate at low E

Asymmetric po decay is constrained ne from µ decay from measured is constrained NCpo rate (po®g) from nµCCQE measurement D resonance rate is constrained

from measured ne from K decay is NCpo rate constrained from SciBooNE high dirt rate is energy nµ event measured from measurement dirt data sample

Major backgrounds are all measured in other data 51 sample andTeppei their Katori, [email protected] are constrained! 24/04/19 1. MiniBooNE 2. Beam 3. Detector 4. Oscillation 5. Discussion 1. MiniBooNE neutrino experiment

2. Booster Neutrino Beamline (BNB)

3. MiniBooNE detector

4. Oscillation candidate search

5. Discussion

Teppei Katori, [email protected] 24/04/19 52 1. MiniBooNE 2. Beam 3. Detector 5. Oscillation candidate event excess 4. Oscillation 5. Discussion

200 < EnQE < 1250 MeV - neutrino mode: Data = 1959 events Bkgd = 1577.8 ± 39.7(stat) ± 75.4(syst) à 381.2 ± 85.2 excess (4.5s)

Old data (50.3%) 162.0 event excess

New data (49.7%) 219.2 event excess

KS test suggests they are compatible P(KS)=76%

53 Teppei Katori, [email protected] 24/04/19 1. MiniBooNE 2. Beam 3. Detector 5. Oscillation candidate event excess 4. Oscillation 5. Discussion

200 < EnQE < 1250 MeV - neutrino mode: Data = 1959 events Bkgd = 1577.8 ± 39.7(stat) ± 75.4(syst) à 381.2 ± 85.2 excess (4.5s) - antineutrino mode: Data = 478 events Bkgd = 398.7 ± 20.0(stat) ± 20.3(syst) à 79.3 ± 28.6 excess (2.8s)

54 Teppei Katori, [email protected] 24/04/19 Detler et al., JHEP08(2018)010 1. MiniBooNE 2. Beam 3. Detector 5. Sterile neutrino hypothesis 4. Oscillation 5. Discussion

Compatible with LSND excess within 2-neutrino oscillation hypothesis

However, appearance and disappearance data have a strong tension (Maltoni, Neutrino 2018)

55 Teppei Katori, [email protected] 24/04/19 1. MiniBooNE 2. Beam 3. Detector 5. Alternative photon production models? 4. Oscillation 5. Discussion

Excess look like more photons (misID) than electrons - peaked forward direction - shape match with po spectrum

Any misID background missing? - New NCg process? - New NCpo process?

or BSM physics? - BSM g production process? - BSM e-scattering process? - BSM oscillation physics?

56 Teppei Katori, [email protected] 24/04/19 MicroBooNE,JINST12(2017)P02017, Public Note: 1041 1. MiniBooNE 2. Beam 3. Detector 5. Liquid argon time projection chamber 4. Oscillation 5. Discussion

MicroBooNE experiment at Fermilab - High resolution detector with e/g separation on BNB - Original motivation of US LArTPC program

dE/dx of first 4cm track (simulation)

57 Teppei Katori, [email protected] 24/04/19 Harvey,Hill,Hill, PRL99(2007)261601 n 1. MiniBooNE 2. Beam 3. Detector 5. Neutrino NC single photon production Z 4. Oscillation 5. Discussion

Z-boson Anomaly mediated g production - process within SM, but not considered. omega meson n n Z g N w w Photon g

X X Particle Zoo, http://www.particlezoo.net/

58 Teppei Katori, [email protected] 24/04/19 Harvey,Hill,Hill, PRL99(2007)261601 n 1. MiniBooNE Lasorak, PhD thesis (Queen Mary, 2018) 2. Beam 3. Detector 5. Neutrino NC single photon production Z 4. Oscillation 5. Discussion

Z-boson Anomaly mediated g production - process within SM, but not considered. omega meson n n Z g N w w Photon g

X X Particle Zoo, http://www.particlezoo.net/

A lot of new calculations - D-radiative decay with nuclear corrections. - all theoretical models and generators more or less agree in MiniBooNE energy region. n n Z g D N N

59 Teppei Katori, [email protected] 24/04/19 Harvey,Hill,Hill, PRL99(2007)261601 1. MiniBooNE Lasorak, PhD thesis (Queen Mary, 2018) 2. Beam 3. Detector 5. Neutrino NC single photon production 4. Oscillation 5. Discussion

NC g production prediction for MiniBooNE - MiniBooNE provides efficiency tables to convert theory à experimental distribution - New models are more or less consistent with MiniBooNE NCg model Hill, PRD84(2011)017501 Zhang and Serot, PLB719(2013)409 Wang et al, PLB740(2015)16

Are we missing any other background processes? - It’s easy to forget processes with s ~ 10-41 cm2 (e.g., diffractive po production s(1GeV) ~ 10-41 cm2 was identified very recently by MINERvA, also neglected by all simulations) MINERvA, PRL117(2016)111801

60 Teppei Katori, [email protected] 24/04/19 T2K, ArXiV:1902.03848 1. MiniBooNE 2. Beam 3. Detector 5. Neutrino NC single photon production 4. Oscillation 5. Discussion

Photon sample NC single gamma sample 30 Data 140 Data Photons 25 NC γ (σ × 300) 120 Other External photons 20 100 Photons from NC 1π0 0 80 15 Photons from νµCC 1π Other 60

Events / 5 MeV 10 Events / 150 MeV 40 5 20

0 0 0 50 100 150 200 250 300 0 500 1000 1500 2000 2500 3000 Reconstructed invariant mass [MeV] Reconstructed photon energy [MeV]

61 Teppei Katori, [email protected] 24/04/19 T2K, ArXiV:1902.03848 1. MiniBooNE MicroBooNE, public note 1041 (2018) 2. Beam 3. Detector 5. Neutrino NC single photon production 4. Oscillation 5. Discussion

T2K near detector - 95% pure photon sample (Minv<50 MeV) - Large external photon background and internal po production background. T2K can only set a limit on this process. NC single gamma Pierre Lasorak candidate event Queen Mary (T2K) à Sussex (DUNE) 10 Wang et al. calculation T2K 90%CL limit MicroBooNE T2K expected 90%CL limit - First large n-LArTPC in USA 1 T2K Flux (all ν, arbitrary unit) - Good e/g PID NOMAD 90%CL limit - Large active veto region −1 T2K limit - Good internal po measurement 10 /nucleon) à Good chance to measure the 2 cm first positive signal of this channel. −2 -38 10 NOMAD limit

(10 MicroBooNE sensitivity? σ −3 Bobby Murrell 10 Manchester (MicroBooNE) −4 10 62 Teppei Katori,10−1 [email protected] 1 24/04/1910 102 Neutrino energy [GeV] deNiverville et al, PRD84(2011)075020 1. MiniBooNE MiniBooNE-DM, PRD98(2018)112004 2. Beam 3. Detector 5. BSM electron scattering models 4. Oscillation 5. Discussion

Dark matter particle - electron scattering New particles created in the beam dump can scatter electrons in the detector.

However, MiniBooNE beam dump mode data shows no excess.

This result set limits on beam dump produced new particle – electron scattering interpretation.

63 Teppei Katori, [email protected] 24/04/19 Gninenko, PRL103(2009)241802 and many others, Jordan et al.,ArXiv:1810.07185 1. MiniBooNE 2. Beam 3. Detector 5. BSM photon production models 4. Oscillation 5. Discussion heavy neutrino decay n Heavy neutrino decay g production nh - Minimum extension of the SM nµ n g - Heavy neutrinos are produced in the beamline µ by kinetically mix with SM neutrinos - Heavy neutrinos decay to SM neutrinos in the Z detector. N N These models have problems because they cannot reproduce the angular distribution of oscillation candidates.

64 Teppei Katori, [email protected] 24/04/19 Gninenko, PRL103(2009)241802 and many others, Jordan et al.,ArXiv:1810.07185 1. MiniBooNE Ballett, et al, JHEP04(2017)102, Bertuzzo et al.,PRL121(2018)241801, Argüelles et al., ArXiv:1812.08768 2. Beam 3. Detector 5. BSM e+e- production models 4. Oscillation 5. Discussion heavy neutrino decay n Heavy neutrino decay g production nh - Minimum extension of the SM nµ n g - Heavy neutrinos are produced in the beamline µ by kinetically mix with SM neutrinos - Heavy neutrinos decay to SM neutrinos in the Z detector. N N These models have problems because they cannot reproduce the angular distribution of Z’ decay oscillation candidates. n Z’ decay model A new class of models predict a heavy neutrino n nh and a neutral heavy boson decaying to e+e-. µ e+ These models explain both energy and angular Z’ e- distributions of MiniBooNE oscillation candidate data. Z’ N N

65 Teppei Katori, [email protected] 24/04/19 Coleman and Glashow, PRD59(1999)116008, TK et al,PRD74(2006)105009, 1. MiniBooNE Diaz and Kostelecký, PLB700(2011)25, Barger et al, PRD84(2011)056014 2. Beam 3. Detector 5. BSM neutrino oscillation models 4. Oscillation 5. Discussion

Lorentz violation as alternative neutrino oscillation model LV-motivated effective Hamiltonian - Making a new texture in Hamiltonian to control oscillations. - Could explain all signals, including LSND and MiniBooNE. - This moment, no LV-motivated models can explain all signals.

It is extremely difficult to make a neutrino oscillation model without neutrino mass, but consistent with all high-precision data. IceCube

Test of Lorentz violation with neutrinos - Almost all neutrino experiments look for Lorentz violation.

- Current best limits of Lorentz violation by neutrinos; Nature Physics Shivesh Mandalia - CPT-odd (dimension-3) < 2.0×10 GeV 14(2018)961 (Queen Mary) - CPT-even (dimension-4) < 2.8×10

It turns out neutrino experiments are one of the highest-precision tests of space-time effects!

66 Teppei Katori, [email protected] 24/04/19 1. MiniBooNE 2. Beam 3. Detector Future of MiniBooNE 4. Oscillation 5. Discussion

MiniBooNE run will be end on June 2019 - Expected to reach ~ 18E20POT in n-mode - The excess may reach ~ 5s

67 Teppei Katori, [email protected] 24/04/19 1. MiniBooNE 2. Beam 3. Detector Future of MiniBooNE 4. Oscillation 5. Discussion

MiniBooNE run will be end on June 2019 - Expected to reach ~ 18E20POT in n-mode - The excess may reach ~ 5s

Next oscillation analysis: timing background rejection - It is possible to reject both intrinsic and misID backgrounds by timing (ongoing)

Bunch structure, data-MC comparison - intrinsic bkgd: µ-decay ne, K-decay ne à slow - misID bkgd: photon conversion à slow

misID bkgd (gamma) intrinsic ne bkgd (µ&K-decay)

external bkgd (dirt event) Oscillation candidate ne (electron)

68 Teppei Katori, [email protected] 24/04/19 1. MiniBooNE 2. Beam 3. Detector Conclusion 4. Oscillation 5. Discussion

MiniBooNE is a short-baseline neutrino oscillation experiment

After 15 years of running - neutrino mode: 381.2 ± 85.2 excess (4.5s) - antineutrino mode: 79.3 ± 28.6 excess (2.8s)

MiniBooNE has many legacies in this community - Many useful tools - Many useful people - Many new topics - Neutrino cross section measurements - Test of Lorentz violation with neutrinos - Direct production & detection Dark Matter search with n-detector - etc.

But the biggest legacy is the short-baseline anomaly

Thank you for your attention! 24/04/19 Teppei Katori, [email protected] 69 1. MiniBooNE 2. Beam 3. Detector 4. Oscillation 5. Discussion

backup

Teppei Katori, [email protected] 24/04/19 70 1. MiniBooNE 2. Beam 3. Detector 4. Oscillation 3. Cross section model 5. Discussion

Predicted event rates before cuts (NUANCE Monte Carlo) Casper, Nucl.Phys.Proc.Suppl.112(2002)161

Event neutrino energy (GeV)

Teppei Katori, [email protected] 24/04/19 71 1. MiniBooNE 2. Beam 3. Detector 4. PID cuts Oscillation candidate events 4. Oscillation 5. Discussion

4 PID cuts (a) Before PID cuts (b) After L(e/mu) cut (c) After L(e/po) cut (d) After mgg cut

Old and new data agree within 2% over 8 years separation.

72 Teppei Katori, [email protected] 24/04/19