T2K Status Report

The Accelerator Complex 2

2010 a Beamline Performance 3 First T2K run completed January to June x protons accumulated for T2K analysis 50 kW stable operation with trials at 100 kW

Beamline Upgrades Beam upgrades were carried out during the summer shutdown Improved kicker magnet power supplies Increased bunch number 6  8 Final installation of horn power supplies Run restarted in November. Now running stably at 115kW Accumulated data already approaching 2010a data set. 4

Monitoring the beam 5 Proton beam precisely tuned (<1mm) to minimize beam loss, and control direction of secondary beam MUMON : profile center < +/- 1 mrad ( Δ E ν peak~2%/mrad)

Understanding Neutrino Production CERN NA61/Shine 6 Need to understand pion production from our target Dedicated experiment NA61 Pilot run in 2007 and high statistics run in Preliminary  + data

Beam Monte Carlo 7 Simulate: Pion /Kaon production in the target Secondary production in the surrounding material Collection of pions by the horn Pion decay to neutrinos Predicts Flux at SK Flux at ND280 Transfer matrix for ND  SK Must match Data from beam monitors Ingrid NA61 Neutrino Flux at SK     e, e

On Axis Neutrinos ; INGRID 8 Iron - Scintillator Detector Monitor the beam by the interaction of the forward muon neutrinos.

The Performance of Ingrid 9 X Beam Profile Y Beam Centre X Beam Centre Y Beam Profile

The ND280 Off-Axis Detector 10 Understanding the beam o  Flux and Spectrum o e Beam Contamination o Neutrino Cross-Sections

Detector Performance 2010a 11 P0D event x-y Distribution ECAL Beam Timing P0D events vs protons on target Beam Centre ECAL events per proton vs time

Events at ND280 12

Analysis at ND280 In 2010a analysis in the tracker uses FGD + TPC tracks 13% acceptance to require the DS ECAL Used for some verification and systematic studies. Measure inclusive  interactions Observe beam e Start work on single  0 production. 13

Muon Neutrinos at ND280 Basic selection Vertex in FGD Track in TPC Provides Momentum and PID Inclusive analysis based on highest energy track Full use of new detector tools Calibration Alignment Data Quality Beam Information Very good initial agreement Systematics still under study. 14

Finding electrons 15 Electron tracks FGD-TPC Include ECAL after first year. Rare Process with large background. Need excellent PID Use the TPC DE/DX Worry about other sources of electrons  0 s and other direct gammas Incoming gammas from outer materials Negative Tracks Muon Control Sample Positive Tracks

A golden e event p~2GeV 16

The Far Detector - SK 17 SK has been running very successfully since 1996 Detector Response is well understood. Upgraded electronics and trigger for T2K running Collect all hits in beam spill window. As the detector is well understood analysis is frozen before data taking.

Beam Events at Super-K 18 Single Ring  -like eventMulti Ring  -like event P  = 1025 MeV/c 1 Michel Electron P  = 1438 MeV/c 2 Michel Electrons

Event timing at Super-K 19 Timing cut suppresses non beam backgrounds Residual atmospheric signal tiny Very good synchronisation with T2K beam achieved

Events in the inner detector 20 Fully Contained Events : 33 Fiducial Volume and Energy > 30MeV : 23

Events in the Outer Detector 21

From 2010a First T2K publication Observation of neutrino oscillations with an off-axis beam. Data Spectra at SK Rate from near detectors Beam Prediction for spectra and near to far ratio. Timescale: several weeks. 22

Prospects for next year 23 T2K aim for 150 kW x10 7 s by July 2011 With this data set sensitivity to  13 surpasses Chooz limit. Full analysis from ND280 Neutrino fluxes and spectra Cross sections The data starts to get very interesting. July 2011 Sensitivity to sin 2 2  13 < 0.05

Liquid Argon

Why Liquid Argon 25 For the next generation neutrino experiments new far detectors will be required. There are a limited number of technologies that can be scaled up to the required size. Liquid argon has the most potential, but is the trickiest. R&D Liquid Argon Program is ongoing here at Liverpool. New Dewer for tests of circulation and purification systems.

Construction of the Liverpool LAr Vessel Left: Rolling the stainless steel sheet Right: Machining the top flange Construction by Kevin McCormick 26

The Liverpool LAr Vessel -Construction Wrapped with Mylar reflector to minimize radiation losses All the welding performed using argon gas to avoid oxidation and achieve UHV 27

The Liverpool LAr Vessel – Closing the Detector 28

Conclusion 29 Liverpool has a strong neutrino program It has been an exciting year in T2K Completion and installation of the barrel ECAL First T2K data. Upgrades and improvements over the summer shutdown By this time next year our data set should provide world leading results for  13. Our liquid argon program provides an eye to the future.