[PPT] - KM3NeT/ORCA: measuring neutrino oscillations and the Mass Hierarchy PowerPoint Presentation

SLIDE 1

KM3NeT/ORCA: measuring neutrino oscillations and the Mass Hierarchy in the Mediterranean

Simon Bourret

Laboratoire APC, CNRS & Université Paris-Diderot

n behalf of the KM3NeT Collaboration

XXVI International Workshop on Weak Interactions and Neutrinos Irvine, California, USA, 19-24 June 2017

SLIDE 2

ν

θz

detector

§ ARCA: Discover/Observe high-energy neutrino sources in the Universe à talk by A. Capone Wed. 21 (astroparticle session) § ORCA: Study ν properties, determine the Neutrino Mass Hierarchy and measure oscillation parameters

WIN 2017 2

IH NH 1 5 10 Eν [GeV] 1 0.5

νe à νµ

P(νx → νμ) for θ=130º - Mantle crossing 1 5 10 Eν [GeV] 1 0.5 P(νx → νμ) for θ=180º - Mantle-core-mantle

νµ à νµ νe à νµ νµ à νµ

KM3NeT/ORCA - S. Bourret

KM3NeT objectives

SLIDE 3

~210 m ~ 2 m 9 m

115 strings
18 DOMs / str
31 PMTs / DOM
Total: 64k PMTs
~8 Mton instrumented (5.7)

WIN 2017 3

43 cm

Optimized for MH sensitivity

3’’ PMT

Eur. Phys. J. C 74, 3056 (2014)

KM3NeT/ORCA - S. Bourret

The ORCA detector

SLIDE 4

§ Vertical spacing optimized for NMH

WIN 2017 4

x [m]

400
200

200 400 y [m]

400
200

200 400 ARCA/ORCA

§ Horizontal spacing adjusted to deployment requirements

è new full MC simulation

MH sensitivity 9m 6m 12m

True NH True IH KM3NeT LoI: J. Phys. G 43 (2016) 0840 (1601.07459)

KM3NeT/ORCA - S. Bourret

Detector geometry

SLIDE 5

WIN 2017 5

“Track”

(ARCA)

νµ CC

ν

KM3NeT/ORCA - S. Bourret

Event topologies: tracks

SLIDE 6

WIN 2017 6

ν NC

(ARCA)

“Cascade”

ν

“Track”

(ARCA)

νµ CC

ν

KM3NeT/ORCA - S. Bourret

Event topologies: cascades

SLIDE 7

§ New loosened trigger è increase of low-E efficiency § Adapted & improved both Track and Shower reconstructions § Particle ID model being refined § NMH & oscillation sensitivities not yet updated with these improvements

WIN 2017 7

KM3NeT preliminary Neutrino Energy [GeV] 5 10 15 20 25 ]

3

Effective Volume [Mm 1 2 3 4 5 6 7 8 9 10

LoI-9m new detector & new trigger/reco new detector & old trigger/reco

KM3NeT Preliminary CC

e

ν &

e

ν

electron channel muon channel

KM3NeT/ORCA - S. Bourret

Updated performance: effective volume

SLIDE 8

§ New loosened trigger è increase of low-E efficiency § Adapted & improved both Track and Shower reconstructions § Particle ID model being refined § NMH & oscillation sensitivities not yet updated with these improvements

WIN 2017 8

KM3NeT preliminary Neutrino energy [GeV] 5 10 15 20 25 30 Median zenith resolution [deg] 5 10 15 LoI-9m new KM3NeT Preliminary CC

e

ν &

e

ν

electron channel muon channel

KM3NeT/ORCA - S. Bourret

Updated performance: zenith resolution

SLIDE 9

LLR

15
10
5

5 10 15

arbitrary units

0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18

§ Profile over 4 oscillation & 5 syst. parameters

WIN 2017 9

IH NH

µIH µNH σIH

SNH = µNH − µIH σIH

§ Generate pseudo-experiments and compute § Median sensitivity ⇔ probability of

bserving median LLR of wrong hierarchy

LLR = log

LNH/LIH
KM3NeT/ORCA - S. Bourret

Statistical analysis

parameter true value distr. initial value/prior distr. treatment prior θ23 [] {40, 42, . . . , 50} uniform over [35, 55] fitted no θ13 [] 8.42 µ = 8.42, σ = 0.26 fitted yes θ12 [] 34 µ = 34, σ = 1 fluct.* N/A ∆M 2 [103 eV2] µ = 2.4, σ = 0.05 µ = 2.4, σ = 0.05 fitted no ∆m2 [105 eV2] 7.6 µ = 7.6, σ = 0.2 fluct.* N/A δCP [] {0, ..., 360} uniform over [0, 360] fitted no

verall flux factor

1 µ = 1, σ = 0.1 fitted yes NC scaling 1 µ = 1, σ = 0.05 fitted yes ν/ν skew µ = 0, σ = 0.03 fitted yes µ/e skew µ = 0, σ = 0.05 fitted yes energy slope µ = 0, σ = 0.05 fitted yes

Table 1: Default parameter settings used for the LLR analysis. For θ23 a total of seven initial values is tried: x+i×5, where x is the randomly drawn value and i ∈ [−3, −2, . . . , 3]. *θ12 and δm2 are assigned a fixed value in the fit, randomly drawn from the initial value distribution.

J. Phys. G 43 (2016) 0840

SLIDE 10

[degrees]

23

θ

40 42 44 46 48 50

] σ Mass hierarchy significance [

1 2 3 4 5 6 7 8

° =0

CP

δ NH, ° =0

CP

δ IH , ° =180

CP

δ NH, ° =180

CP

δ IH ,

)

23

θ (

2

sin

0.4 0.45 0.5 0.55 0.6 WIN 2017 10

§ ~ 3σ MH sensitivity in 3 years § The true value of δcp has small but non-negligible impact § The combination of NH and upper octant of θ23 would significantly improve sensitivity (5σ in 3 years) § In the IH, sensitivity is mostly independent of octant of θ23

(LoI - 9m spacing) (LoI - 9m spacing)

KM3NeT/ORCA - S. Bourret

Sensitivity results (LoI detector)

J. Phys. G 43 (2016) 0840

Date 2020 2021 2022 2023 2024 2025 ] σ Median Significance [ 1 2 3 4 5 6 7 8

° = 42

23

θ NH, ° = 42

23

θ IH, ° = 48

23

θ NH, ° = 48

23

θ IH,

KM3NeT preliminary

SLIDE 11

WIN 2017 11

§ Achieve 2-3% prec. in Δm2

32 and 4-10% in sin2θ23 (3 years)

§ Competitive with LBL experiments projected sensitivity in 2020 § Early determination of the octant of θ23 is feasible

KM3NeT/ORCA - S. Bourret

Oscillation parameters measurement

J. Phys. G 43 (2016) 0840

T2K 2015 NOvA 2020 T2K 2020 MINOS ORCA 3 years (MH known)

68% C.L. NH assumed

(LoI – 9m)

NH, δCP = 0, maximal mixing assumed § Analysis based on Asimov datasets § θ12, θ13 and δm2 fixed § Other param. unconstrained § Energy scale uncertainty added (has no impact on NMH sens.)

SLIDE 12

WIN 2017 12

§ Achieve 2-3% prec. in Δm2

32 and 4-10% in sin2θ23 (3 years)

§ Competitive with LBL experiments projected sensitivity in 2020 § Early determination of the octant of θ23 is feasible

KM3NeT/ORCA - S. Bourret

Oscillation parameters measurement

J. Phys. G 43 (2016) 0840

KM3NeT preliminary

(LoI - 9m) 1σ 2σ

NH assumed, δCP = 0

MH known MH unknown

§ Analysis based on Asimov datasets § θ12, θ13 and δm2 fixed § Other param. unconstrained § Energy scale uncertainty added (has no impact on NMH sens.)

SLIDE 13

WIN 2017 13

§ ντ appearance tests PMNS unitarity and BSM theories § ~ 3k ντ CC events/year with full ORCA § Rate constrained within ~10% in 1 year § Sensitivity with few strings is under study

ç no appearance ç unitarity § analysis uses same PID as NMH (not optimised for ντ) § prior on NC norm. (30%) and skew (10%)

KM3NeT preliminary

1σ 2σ 3σ 5σ

KM3NeT/ORCA - S. Bourret

Tau neutrino appearance

ν/ν

SLIDE 14

§ The dominant effect in ORCA of adding a eV scale sterile neutrino would be the suppression

f νµ è ντ oscillation at ~20 GeV

§ With 1 year of data ORCA is sensitive to |Uτ4|2 values smaller than current limits set by SK

WIN 2017 KM3NeT/ORCA - S. Bourret 14

Light sterile neutrino

§ Fitted: 4 syst. + 2 osc. (θ23, ΔM2) § Ue4 = 0 § Δm2

41 = 0.3 eV2

SLIDE 15

§ With only 1 year of data, ORCA sensitive to NSI effects below these limits: § Current limits:

Rept. Prog. Phys. 76, 044201 (2013)

WIN 2017 KM3NeT/ORCA - S. Bourret 15

Non-Standard Interactions

§ Fitted: 4 syst. + 2 osc. (θ23, ΔM2) § 95% C.L. in (|εee|, |εeτ|, |εττ|) space à 2D projection for |εee| = 0 § SK + K2K limits from arXiv:0506143

à see e.g. talk by I. Mocioiu Tue. 20 (ν session)

SLIDE 16

WIN 2017 16

§ 7 strings funded for ORCA (11 M€

inc. infrastructure)

§ 2 strings deployment Sept. 17 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 ORCA Construction MH Determination

7 Strings Operational 115 Strings Full Detector

WIN 2017

1st node: Sept 2016

Total ORCA cost: ~45 M€

1st ORCA string ready KM3NeT/ORCA - S. Bourret

Funding and timeline

SLIDE 17

WIN 2017 17

§ ORCA is being built in the Mediterranean sea to measure

scillations with atmospheric neutrinos: detector is to be

completed by 2020 § Main goal is to determine the Neutrino Mass Hierarchy, with a sensitivity of >3σ in 3 years of operation § ORCA will also improve measurements of other oscillation parameters such as Δm2

32 and θ23

§ Further physics potential: PMNS unitarity, sterile ν’s, NSI… § More topics not adressed in this talk: DM detection, Earth tomography, supernovae…

KM3NeT/ORCA - S. Bourret

KM3NeT/ORCA: measuring neutrino oscillations and the Mass Hierarchy in the Mediterranean

Simon Bourret

XXVI International Workshop on Weak Interactions and Neutrinos Irvine, California, USA, 19-24 June 2017

ν

θz

§ ARCA: Discover/Observe high-energy neutrino sources in the Universe à talk by A. Capone Wed. 21 (astroparticle session) § ORCA: Study ν properties, determine the Neutrino Mass Hierarchy and measure oscillation parameters

νe à νµ

νµ à νµ νe à νµ νµ à νµ

KM3NeT objectives

~210 m ~ 2 m 9 m

43 cm

Optimized for MH sensitivity

3’’ PMT

The ORCA detector

§ Vertical spacing optimized for NMH

§ Horizontal spacing adjusted to deployment requirements

è new full MC simulation

Detector geometry

“Track”

νµ CC

ν

Event topologies: tracks

ν NC

“Cascade”

ν

“Track”

νµ CC

ν

Event topologies: cascades

§ New loosened trigger è increase of low-E efficiency § Adapted & improved both Track and Shower reconstructions § Particle ID model being refined § NMH & oscillation sensitivities not yet updated with these improvements

electron channel muon channel

Updated performance: effective volume

§ New loosened trigger è increase of low-E efficiency § Adapted & improved both Track and Shower reconstructions § Particle ID model being refined § NMH & oscillation sensitivities not yet updated with these improvements

electron channel muon channel

Updated performance: zenith resolution

§ Profile over 4 oscillation & 5 syst. parameters

IH NH

SNH = µNH − µIH σIH

§ Generate pseudo-experiments and compute § Median sensitivity ⇔ probability of

LLR = log

Statistical analysis

§ ~ 3σ MH sensitivity in 3 years § The true value of δcp has small but non-negligible impact § The combination of NH and upper octant of θ23 would significantly improve sensitivity (5σ in 3 years) § In the IH, sensitivity is mostly independent of octant of θ23

Sensitivity results (LoI detector)

§ Achieve 2-3% prec. in Δm2

§ Competitive with LBL experiments projected sensitivity in 2020 § Early determination of the octant of θ23 is feasible

Oscillation parameters measurement

NH, δCP = 0, maximal mixing assumed § Analysis based on Asimov datasets § θ12, θ13 and δm2 fixed § Other param. unconstrained § Energy scale uncertainty added (has no impact on NMH sens.)

§ Achieve 2-3% prec. in Δm2

§ Competitive with LBL experiments projected sensitivity in 2020 § Early determination of the octant of θ23 is feasible

Oscillation parameters measurement

NH assumed, δCP = 0

§ Analysis based on Asimov datasets § θ12, θ13 and δm2 fixed § Other param. unconstrained § Energy scale uncertainty added (has no impact on NMH sens.)

§ ντ appearance tests PMNS unitarity and BSM theories § ~ 3k ντ CC events/year with full ORCA § Rate constrained within ~10% in 1 year § Sensitivity with few strings is under study

Tau neutrino appearance

ν/ν

§ The dominant effect in ORCA of adding a eV scale sterile neutrino would be the suppression

§ With 1 year of data ORCA is sensitive to |Uτ4|2 values smaller than current limits set by SK

Light sterile neutrino

§ Fitted: 4 syst. + 2 osc. (θ23, ΔM2) § Ue4 = 0 § Δm2

§ With only 1 year of data, ORCA sensitive to NSI effects below these limits: § Current limits:

Non-Standard Interactions

à see e.g. talk by I. Mocioiu Tue. 20 (ν session)

§ 7 strings funded for ORCA (11 M€

§ 2 strings deployment Sept. 17 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 ORCA Construction MH Determination

Total ORCA cost: ~45 M€

Funding and timeline

§ ORCA is being built in the Mediterranean sea to measure

completed by 2020 § Main goal is to determine the Neutrino Mass Hierarchy, with a sensitivity of >3σ in 3 years of operation § ORCA will also improve measurements of other oscillation parameters such as Δm2

§ Further physics potential: PMNS unitarity, sterile ν’s, NSI… § More topics not adressed in this talk: DM detection, Earth tomography, supernovae…

Summary