Analysis of first KM3NeT/ORCA data J. Schumann July 29, 2019 - - PowerPoint PPT Presentation

▶
analysis of first km3net orca data
SMART_READER_LITE
LIVE PREVIEW

Analysis of first KM3NeT/ORCA data J. Schumann July 29, 2019 - - PowerPoint PPT Presentation

Sep 17, 2023 375 likes •575 views

Analysis of first KM3NeT/ORCA data J. Schumann July 29, 2019 FRANCI 2019, Erlangen Overview KM3NeT : Water Cherenkov detector in the Mediterranean Sea Detector is split up and deployed at two sites: ARCA Astroparticle research

slide-1
SLIDE 1

Analysis of first KM3NeT/ORCA data

  • J. Schumann

July 29, 2019 FRANCI 2019, Erlangen

slide-2
SLIDE 2

Overview

  • KM3NeT: Water Cherenkov

detector in the Mediterranean Sea

  • Detector is split up and deployed at

two sites:

→ ARCA

Astroparticle research

→ ORCA Neutrino oscillation research

8 Mton instrumented mass

  • Current project status:

→ Deployment for Phase-1 (7 DUs) → Four detection units (DU) installed

and taking data

Artist impression of the KM3NeT detector

⇒ First data available → Data Analysis

July 29, 2019 | Johannes Schumann | FRANCI19 | Analysis of first ORCA data 2/18

slide-3
SLIDE 3

Detection Unit & Reconstruction

  • Detection Unit:

18 DOMs, 31 photomultipliers each

  • Dataset Livetime 1 DU → 82 days

2 DUs → 17 days

  • Event Reconstruction:

→ Maximum likelihood method for track

hypothesis using PDFs generated from Monte-Carlo simulations

  • Task:

→ Search for neutrino candidates requires

dedicated event selection

~30m ~9m

νμ μ-

θZenith

rvertex zvertex

~20m

July 29, 2019 | Johannes Schumann | FRANCI19 | Analysis of first ORCA data 3/18

slide-4
SLIDE 4

Analysis Details & Event Selection Cuts

slide-5
SLIDE 5

Reconstructed Events

  • Problem:

→ Event rate dominated by atmospheric down-going muons → Rate of ’up-going’, i.e. mis-reconstructed, muon events

still ∼ 104 higher than actual neutrino event rate

  • up-going events → Neutrino events

1.00 0.75 0.50 0.25 0.00 0.25 0.50 0.75 1.00

cos( )

102 103 104 105

Events

nu (1DU) ×103 data (1DU) muon (1DU) nu (2DUs) ×103 data (2DUs) muon (2DUs)

Zenith distribution of all reconstructed events

~30m ~9m

νμ μ-

θZenith

rvertex zvertex

July 29, 2019 | Johannes Schumann | FRANCI19 | Analysis of first ORCA data 5/18

slide-6
SLIDE 6

Event Topology

  • Event trigger:

large clusters of causally connected detected photons at the PMTs (hit)

  • Search for hit patterns of up-going events
  • Identification of (spacial) characteristics for event selection

Simulated atmospheric muon event Simulated neutrino event

July 29, 2019 | Johannes Schumann | FRANCI19 | Analysis of first ORCA data 6/18

slide-7
SLIDE 7

Data / Monte-Carlo comparison

  • Data is in good agreement with Monte-Carlo simulations

0.0 2.5 5.0 7.5 10.0 12.5 15.0 17.5 20.0

n

102 103 104 105 106

Events

muon data nu x 1.0e+04

Number of triggered DOMs (1 DU)

20 40 60 80 100

rvtx

101 102 103 104 105 106 107

Events

muon data nu x 1.0e+04

Radial vertex distance (1 DU)

0.0 2.5 5.0 7.5 10.0 12.5 15.0 17.5 20.0

n

102 103 104 105 106

Events Triggered DOMs (No Event Selection)

muon data nu x 1.0e+04

Number of triggered DOMs (2 DUs)

20 40 60 80 100

rvtx

101 102 103 104 105 106 107

Events Radial Vertex Distance (No Event Selection)

muon data nu x 1.0e+04

Radial vertex distance (2 DUs)

July 29, 2019 | Johannes Schumann | FRANCI19 | Analysis of first ORCA data 7/18

slide-8
SLIDE 8

Geometrical Cuts

  • Require reconstructed tracks close to the DU(s)
  • Horizontal muon tracks below the DU(s) create

(also) up-going patterns

50 100 150 200

ztrg

0.0 0.5 1.0 1.5 2.0 2.5 3.0

Events

×104 nu (1DU) ×1000 muon (1DU) nu (2DUs) ×1000 muon (2DUs)

Mean height of tiggered hits Cut: ztrg > 40 m

20 40 60 80 100

rvtx

0.00 0.25 0.50 0.75 1.00 1.25 1.50

Events

×103 nu (1DU) ×1000 muon (1DU) nu (2DUs) ×1000 muon (2DUs)

Radial distance of the reco. vertex Cut: rvtx < 20 m

~30m ~9m

νμ μ-

θZenith

rvertex zvertex

~20m

July 29, 2019 | Johannes Schumann | FRANCI19 | Analysis of first ORCA data 8/18

slide-9
SLIDE 9

Likelihood / Reconstruction Cuts

  • Check likelihood value of best

up-going solution

  • Other cuts:

→ Likelihood value difference

between best up- and down-going solution

  • Possible improvements:

→ Use likelihood value normalised

to number of degrees of freedom

25 50 75 100 125 150 175 200

Qup

1 2 3 4

Events

×10 1 nu (1DU) muon (1DU) nu (2DUs) muon (2DUs)

Likelihood of best up-going solution Cut: Qup > 40

July 29, 2019 | Johannes Schumann | FRANCI19 | Analysis of first ORCA data 9/18

slide-10
SLIDE 10

Resulting Zenith Distribution

Analysis Initial events

ν Candidates (MC)

Mis-reco. muons in MC Rate

1DU 1.4 × 107 17(5.2) 1 0.2 / day 2DU 5.0 × 106 43(1.4) 2.5 / day 2DU (min. muons) 5.0 × 106 81(5.22) 4.8 / day

1.0 0.8 0.6 0.4 0.2 0.0

cos( )

10 2 10 1 100 101

Events

muon data nu 1.0 0.8 0.6 0.4 0.2 0.0

cos( )

10 2 10 1 100 101

Events Zenith (Neutrino Selection)

muon data nu July 29, 2019 | Johannes Schumann | FRANCI19 | Analysis of first ORCA data 10/18

slide-11
SLIDE 11

Final Remarks / Outlook

  • Event reconstruction with one/two DUs

→ Neutrino identification possible → Features for Sparking PMTs and Bioluminesence effects needed

  • No blinding → Main goal: understanding the detector

⇒ Focus on geometrical cuts

  • Current status:

→ Preliminary Results → Start from other ongoing collaboration analysis (cross-check) → Most promising: Arrival time residual w.r.t. reco. hypothesis

  • Outlook:

→ Use also the four installed DUs → Development of (new) cut features on-going

July 29, 2019 | Johannes Schumann | FRANCI19 | Analysis of first ORCA data 11/18

slide-12
SLIDE 12

Thank you for your attention!

slide-13
SLIDE 13

Backup

slide-14
SLIDE 14

Neutrino Candidate

250 500 750 1000 1250 1500 1750 2000

Time [ns]

50 100 150 200

z [m]

cos(Zenith)=0.563442000012 Run: 4919, EventID: 12281

100 50 50 100 150 200

Time residual [ns]

50 75 100 125 150 175

z [m]

250 500 750 1000 1250 1500 1750

Time [ns]

50 100 150 200

z [m]

100 50 50 100 150 200

Time residual [ns]

50 75 100 125 150 175

z [m]

250 500 750 1000 1250 1500 1750 2000

Time [ns]

50 100 150 200

z [m]

cos(Zenith)=0.563442000012 Run: 4919, EventID: 12281

100 50 50 100 150 200

Time residual [ns]

50 75 100 125 150 175

z [m]

250 500 750 1000 1250 1500 1750

Time [ns]

50 100 150 200

z [m]

100 50 50 100 150 200

Time residual [ns]

50 75 100 125 150 175

z [m]

Run: 4919, EventId: 12281, cos(Θ) = 0.56

July 29, 2019 | Johannes Schumann | FRANCI19 | Analysis of first ORCA data 14/18

slide-15
SLIDE 15

Reconstuction Hit Selection

250 500 750 1000 1250 1500 1750

Time [ns]

50 100 150 200

z [m]

cos(Zenith)=0.194254508542 Run: 4897, EventID: 24439

100 50 50 100 150 200

Time residual [ns]

50 100 150

z [m]

500 1000 1500 2000

Time [ns]

50 100 150 200

z [m]

100 50 50 100 150 200

Time residual [ns]

50 100 150

z [m]

250 500 750 1000 1250 1500 1750

Time [ns]

50 100 150 200

z [m]

cos(Zenith)=0.194254508542 Run: 4897, EventID: 24439

100 50 50 100 150 200

Time residual [ns]

50 100 150

z [m]

500 1000 1500 2000

Time [ns]

50 100 150 200

z [m]

100 50 50 100 150 200

Time residual [ns]

50 100 150

z [m]

Run: 4897, EventId: 24439, cos(Θ) = 0.19

July 29, 2019 | Johannes Schumann | FRANCI19 | Analysis of first ORCA data 15/18

slide-16
SLIDE 16

Sparking PMT

250 500 750 1000 1250 1500 1750 2000

Time [ns]

50 100 150 200

z [m]

cos(Zenith)=0.873935298157 Run: 5004, EventID: 22573

100 50 50 100 150 200

Time residual [ns]

25 50 75 100 125 150 175

z [m]

200 400 600 800 1000 1200 1400

Time [ns]

50 100 150 200

z [m]

100 50 50 100 150 200

Time residual [ns]

25 50 75 100 125 150 175

z [m]

250 500 750 1000 1250 1500 1750 2000

Time [ns]

50 100 150 200

z [m]

cos(Zenith)=0.873935298157 Run: 5004, EventID: 22573

100 50 50 100 150 200

Time residual [ns]

25 50 75 100 125 150 175

z [m]

200 400 600 800 1000 1200 1400

Time [ns]

50 100 150 200

z [m]

100 50 50 100 150 200

Time residual [ns]

25 50 75 100 125 150 175

z [m]

Run: 5004, EventId: 22573, cos(Θ) = 0.87

July 29, 2019 | Johannes Schumann | FRANCI19 | Analysis of first ORCA data 16/18

slide-17
SLIDE 17

Bioluminesence

400 600 800 1000 1200 1400 1600 1800

Time [ns]

50 100 150 200

z [m]

cos(Zenith)=0.744312870382 Run: 4814, EventID: 7878

100 50 50 100 150 200

Time residual [ns]

50 75 100 125 150 175

z [m]

500 1000 1500 2000

Time [ns]

50 100 150 200

z [m]

100 50 50 100 150 200

Time residual [ns]

50 75 100 125 150 175

z [m]

400 600 800 1000 1200 1400 1600 1800

Time [ns]

50 100 150 200

z [m]

cos(Zenith)=0.744312870382 Run: 4814, EventID: 7878

100 50 50 100 150 200

Time residual [ns]

50 75 100 125 150 175

z [m]

500 1000 1500 2000

Time [ns]

50 100 150 200

z [m]

100 50 50 100 150 200

Time residual [ns]

50 75 100 125 150 175

z [m]

Run: 4814, EventId: 7878, cos(Θ) = 0.74

July 29, 2019 | Johannes Schumann | FRANCI19 | Analysis of first ORCA data 17/18

slide-18
SLIDE 18

Misreconstructed muon candidate

500 1000 1500 2000

Time [ns]

50 100 150 200

z [m]

cos(Zenith)=0.949876689929 Run: 4893, EventID: 6095

100 50 50 100 150 200

Time residual [ns]

50 100 150

z [m]

500 1000 1500 2000

Time [ns]

50 100 150 200

z [m]

100 50 50 100 150 200

Time residual [ns]

50 100 150

z [m]

500 1000 1500 2000

Time [ns]

50 100 150 200

z [m]

cos(Zenith)=0.949876689929 Run: 4893, EventID: 6095

100 50 50 100 150 200

Time residual [ns]

50 100 150

z [m]

500 1000 1500 2000

Time [ns]

50 100 150 200

z [m]

100 50 50 100 150 200

Time residual [ns]

50 100 150

z [m]

Run: 4893, EventId: 6095, cos(Θ) = 0.95

July 29, 2019 | Johannes Schumann | FRANCI19 | Analysis of first ORCA data 18/18