The T2K Neutrino Experiment

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Letitia Lawrence
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1 The T2K Neutrino Experiment Tokai to Kamioka TPC-Group, Institute 3b Achim Stahl, Stefan Roth, Karim Laihem, Dennis Terhorst, Jochen Steinmann , Bad Honnef

2 Overview 1. Neutrinos Mixing and Oscillation 2. Physics Motivation for T2K 3. T2K Experiment Overview Beam Generation Neutrino Detection 4. RWTH Contribution TPC-Group Activities 2

3 Neutrino Mixing Similar to the Cabbibo-Kobayashi-Maskawa Matrix in the quark sector the neutrino mass eigenstates are a combination of the different flavour eigenstates Mixing angles: 12, 23, 13 Phases:, 1, 2 3

4 Neutrino Oscillation W The neutrino is always produced in its flavour eigenstate. Schrödingers Equation propagate Distance L Probability to detect a different flavour neutrino after traveling distance L 4

5 Neutrino Oscillation Two Neutrino Oscillation Example (in vacuum) oscillation probability after L = 295 km mij 2 4LE 1.27 mij 2 (ev²) L (km) E (GeV) 5

6 Physics Motivation Observation of Neutrino Oscillation 2 23 disappearance 23 and m m23 =10 ev e appearance non-zero 13 2 sin 2 13 =0.01 detect 2 sin

7 T2K Tokai to Kamiokande -Neutrino Beam from J-PARC, Tokai to Super-KamiokaNDE 7

Linac, * 600-MeV superconducting Linac * 3-GeV rapid cycling synchrotron

8 J-PARC (Tokai) Japan - Proton Accelerator Research Center The accelerator complex consists of following accelerators: * 400-MeV normal-conducting Linac, * 600-MeV superconducting Linac * 3-GeV rapid cycling synchrotron ring (333µA, 1MW) very high intensity!! * 50-GeV main ring, (15µA, 0.75MW) 8

9 J-PARC (Tokai) Howto create a neutrino beam p (50GeV) Hadronic Shower Carbon Target Decay pipe 9

10 J-PARC Neutrino Facilities Proton Beam Transport Feb

11 J-PARC Neutrino Facilities Target Station Graphite-rod in Ti-alloy housing (900mm x 26mmØ) 11

12 J-PARC Neutrino Facilities Target Station 12 12

13 J-PARC Neutrino Facilities Neutrino Facilities 13

14 J-PARC (Tokai) Near Detector 280m (ND280) Detect composition of nu-beam and normailzation of flux UA1 Magnet (0.2T), particle identification and calorimeter 14

15 Off-Axis Beam Characteristic 15

16 Neutrino Beam 16

Cherenkov detector, with 11,000 photomultiplier tubes,

17 Super KamiokaNDE Nucleon Decay Experiment / Neutrino DEtector Super-Kamiokande is a 50,000 ton water Cherenkov detector, with 11,000 photomultiplier tubes, which started observation in 1996 after 5 years of construction 17

W High energetic charged particle emits Cherenkov-light if it is faster than the speed of light in

18 Super KamiokaNDE Neutrino Detection in a Water Cherenkov Detector p n l + p {e, } n Neutrino converts to its charged leptonic partner by a charged current interaction. W High energetic charged particle emits Cherenkov-light if it is faster than the speed of light in its surrounding medium. l Cherenkov energy thresholds for Super Kamiokande Charged lepton direction gives approximate neutrino direction 18

19 Super KamiokaNDE Muon-like event Electron-like event 19

20 Expected Sensitivity Search for e-appearance assumed to be running at 750kW for 5 years, using the 22.5 kton fiducial volume SK detector C H O O Z ex c lu de d Plot assumptions: sin = sin =1.0 m 122 = ev 2 CP =0 normal hierarchy 2 sin 2 13 one order of magnitude better! 20

21 RWTH Contributions to T2K/ND280 Magnet Moving System Gas Monitor Chambers

22 TPC and Gas Monitor Chamber Time Projection Chamber Measurement of gain and drift velocity,... Live gas monitoring (approx. each 5 minutes) Micromegas as Anode 22

23 Micromegas Micro Mesh Gaseous Structure gas amplification by ionization cascade ~0.1mm Drift tube GEM foils Micromegas 23

24 Gas Monitor Chamber Simultanious measurement of drift velocity and gain: Fe-55 photons ionize one Argon atom, the electron produces ~200 more electrons by ionization. Charge measurement on the Micromegas pad gives gas amplification. cathode side Sr-90 electrons ionize Argon atoms on their track. This ionization track drifts down to the Micromegas. Drift time is measured from a scintillator based trigger (primary electron) to detection on the MM, and gives drift velocity. E Anode / Micromegas side 24

25 Chamber Overview Micromegas Cathode 25

26 Gain Measurement Relative Variation of Gain with Pressure 6 kev 3 kev charge on pad G /G =4.66 p/ p 26

27 Drift Velocity Measurement 27

28 Summary Monitor Chambers nearly ready for installation The T2K Experiment will enhance and extend our knowledge about Neutrino parameters of 2 the standard model m23, 23 and 13 Data taking is about to start end

29 Summary Monitor Chambers nearly ready for installation The T2K Experiment will enhance and extend our knowledge about Neutrino parameters of 2 the standard model m23, 23 and 13 Data taking is about to start end 2009 Thank you! 29

30 References The JHF-Kamioka neutrino project (arxiv: hep-ex/ v1) T2K Collaboration - J-PARC - ND Super-Kamiokande - (Target Station Photos from 30

31 BACKUP 31

32 Expected Sensitivity 32

33 Near Detector nd280 33

34 Project Description The JHF-Kamioka neutrino project is a second generation long base line neutrino oscillation experiment that probes physics beyond the Standard Model by high precision measurements of the neutrino masses and mixing. A high intensity narrow band neutrino beam is produced by secondary pions created by a high intensity proton synchrotron at JHF (JAERI). The neutrino energy is tuned to the oscillation maximum at ~1 GeV for a baseline length of 295 km towards the world largest water Cerenkov detector, Super-Kamiokande. Its excellent energy resolution and particle identification enable the reconstruction of the initial neutrino energy, which is compared with the narrow band neutrino energy, through the quasi-elastic interaction. The physics goal of the first phase is an order of magnitude better precision in the nu_mu to nu_tau oscillation measurement (delta(delta m_23^2)=10^-4 ev^2 and delta(sin^22theta_23)=0.01), a factor of 20 more sensitive search in the nu_mu to nu_e appearance (sin^22theta_{mu e} ~ 0.5sin^22theta_{13}>0.003), and a confirmation of the nu_mu to nu_tau oscillation or discovery of sterile neutrinos by detecting the neutral current events. In the second phase, an upgrade of the accelerator from 0.75 MW to 4 MW in beam power and the construction of 1 Mt Hyper-Kamiokande detector at Kamioka site are envisaged. Another order of magnitude improvement in the nu_mu to nu_e oscillation sensitivity, a sensitive search of the CP violation in the lepton sector (CP phase "delta" down to degrees), and an order of magnitude improvement in the proton decay sensitivity is also expected. (arxiv:hep-ex v1) 34

Recent T2K results on CP violation in the lepton sector

Recent T2K results on CP violation in the lepton sector presented by Per Jonsson Imperial College London On Behalf of the T2K Collaboration, December 14-20 2016, Fort Lauderdale, USA. Outline Neutrino