1. CHIPP 2 October 2006 Alain Blondel HARP-K2K-T2K 1. The K2K and T2K experiments 2. beam related uncertainties 3. HARP and results 4. K2K and results 5. T2K 6. conclusions

2. CHIPP 2 October 2006 Alain Blondel JPARC- ~0.6GeV beam 0.75 MW 50 GeV PS (2009  ) Kamioka J-PARC SK: 22.5 kt Phase II: 4 MW upgrade Phase II HK: 1000 kt K2K ~1.2 GeV beam 0.01 MW 12 GeV PS (1999  2005) (1999  2005) K2K & T2K

3. CHIPP 2 October 2006 Alain Blondel K2K ran 1999-2001 2003-2004 12 GeV protons WBB flux X cross-sections poorly known from first principles measured in near detectors: Most useful turned out to be -- scibar (water + scint) -- MRD

4. CHIPP 2 October 2006 Alain Blondel Far flux different from near flux (solid angle) neutrino cross-sections poorly known at low energies near detector is also a cross-section measurement device, PROVIDED FLUX IS KNOWN ==> hadron production measurements far/near ratio

5. CHIPP 2 October 2006 Alain Blondel Hadron production on nuclear targets is a) complicated b) uninteresting for hadronic physics c) difficult to measure well d) absolutely mandatory for neutrino beam experiments ==> data are sparse and Monte-Carlos are very uncertain measure!

6. CHIPP 2 October 2006 Alain Blondel HARP approved 2000 built in 17 months run sept. 2001 -> nov 2002 10 6 triggers at each of these settings Beam line PID Forward detectors --> neutrino beams - K2K, - Miniboone, - atmospheric, - Low energy SPL superbeam Large Angle detectors -->neutrino factory

7. CHIPP 2 October 2006 Alain Blondel Uni-Ge: A.B, Borghi, Campanelli, Cervera, Gilardoni, Graulich, Morone, Prior, Schroeter

8. CHIPP 2 October 2006 Alain Blondel HARP large angle S. Borghi

9. CHIPP 2 October 2006 Alain Blondel no oscillation flux*0.6 best osc. fit reconstructed « single ring » Quasi-elastics in SuperKamiokande ==> spectral shape + normalization show oscillation K2K final results (using HARP input, 4.1 -> 4.4  C.L. improved by factor 3) arXiv:hep-ex/0606032 v2 sept 06 (Blondel, Borghi, Cervera, Schroeter) + papers on  0 production and quasi-elastics

10. CHIPP 2 October 2006 Alain Blondel p  140m0m280m2 km295 km on-axis off-axis T2K (Re13@CERN) SK  monitor ND280m ND2km neutrino decay volume Possible Future

11. CHIPP 2 October 2006 Alain Blondel OA3°  Target Horns Decay Pipe SuperK OA2° OA2.5° T2K principles 0o0o - off-axis beam - E reconstruction using CCQE kinematics  n   - p - small contamination of e - PID at SK  /e identification background suppression in e search (K2K) e-like  -like - spectrum at SuperK predicted by correction of spectrum at Near Detector (ND280m) by Far/Near ratio

12. CHIPP 2 October 2006 Alain Blondel T2K Physics Goals 2 Measurement of  m 2 23 with accuracy of 3% mixing angle with accuracy of 1%  (sin 2 2  23 )  0.01  (  m 2 23 ) < 1  10 -4 eV 2 3 Search for sterile components by NC events 1 Search for e appearance sensitivity sin 2 2  13  0.01

13. CHIPP 2 October 2006 Alain Blondel Beam line construction started in April 2004 on schedule Start of ND280m detectors manufacturing Fall 2006 ND280 hall construction start April 2007 UA1 magnet installation May 2008 Complete ND280 building December 2008 50 GeV MR commissioning 2008 Begin installation of ND280 detectors January 2009 Neutrino beam line commissioning April 2009 T2K physics run 2009 …..

14. CHIPP 2 October 2006 Alain Blondel 2 km detector will be discussed after successful operation of T2K phase I experiment (2009)

15. CHIPP 2 October 2006 Alain Blondel Target and horn magnets 1st Horn excitation May 2006 Operation at 320 kA July 2006 Production of 1, 2, 3 Horns 2007 Installation 2008 1st Horn2nd Horn 3rd Horn Graphite Target beam I=320kA Graphite target Prototype - thermal shock resistant to 0.75 MW - He-gas cooling system

16. CHIPP 2 October 2006 Alain Blondel Requirements for Near Detectors determination of off-axis angle (on-axis detector)  and e fluxes, from CC(off-axis tracking detectors)  0 production cross sections (Pi-Zero, Ecal)  n   - p CCQE E   1GeV,   = 0 – 180 deg Fermi motion  Muon momentum resolution – 100MeV/c  + /  - and e + /e - identification Detection of recoil protons Charged pion measurement Measurement of e contamination with <10% uncertainty Measurements of neutrino interactions in water target Neutrino beam direction accuracy <<1 mrad Neutrino flux measurement at ND280 with accuracy 5%

17. CHIPP 2 October 2006 Alain Blondel Near Detectors at 280 m Off-axis (~2 o ) On-axis (0 o )  19m Super-K Beam center 37m ND280m hall Accuracy of beam direction 0.18 mrad

18. CHIPP 2 October 2006 Alain Blondel ND280m off-axis detector UA1 magnet 0.2 T inner volume: 3.5  3.6  7.0 m 3 Pi-Zero optimized for  0 from NC Tracker optimized for CC studies surrounded by ECAL and Side Muon Range Detector SMRD Conceptual design TDR being written

19. CHIPP 2 October 2006 Alain Blondel ND280m tracker solid active (+ water) target modules (FGD) gas time projection chamber modules (TPC) 3 TPC’s 2.5m x 2.5 m x 90 cm Gas amplification Micromegas Barcelona-GVA-Saclay 26cm - 6 read-out planes (0.6x2.5 m 2 ) - Total drift distance 1.25 m - B=0.2 T E=200V/cm - Pad size: 0.6 to 0.8 cm - ~100k channels  p/p 2 =7% in one chamber Requirements : σ(p)/p < 10 % at 1 GeV/c dE/dx capability: separate e from μ

20. CHIPP 2 October 2006 Alain Blondel Swiss contributions to T2K UniGe: Construction of Micromegas modules (84 modules + spares) at CERN: mechanics + automatic bench testing and pad-by-pad calibration (~150000 channels) (Abgrall, AB, Bravar, Di Marco, Ferrere, Ravonel, Schroeter) + contribution to refurbisment of UA1 magnet (shared contribution by EU groups)

21. CHIPP 2 October 2006 Alain Blondel Very good news: UniBe and ETHZ have applied to T2K -- proposed contribution to ND280 detectors under discussion -- long term interest in a possible 2km Larg detector Under investigation: -- Swiss groups could lead the effort of NA49/T2K --> -- Measurement of particle production by 30-50 GeV protons from carbon target in the NA49 apparatus Swiss contributions to T2K

22. CHIPP 2 October 2006 Alain Blondel NA-49 Set-up beam TPC ToF NA49-future: Study of hadron production in collisions of protons and nuclei at the CERN SPS

23. CHIPP 2 October 2006 Alain Blondel CONCLUSIONS -- Starting from HARP, we are building up an increasingly strong EU and CH contribution to the Japanese Long-baseline neutrino programme -- K2K confirmed the existence of oscillations with an accelerator neutrino beam -- Hadroproduction measurement have shown to be i) difficult and ii) important for understandng of oscillation experiments. -- T2K experiment is so far on schedule to start in spring 2009. Intensity is expected to increase slowly to reach nominal in 2011 and beyond later -- The main goal of T2K is the   e search (a critical step towards leptonic CP violation) there is much we do not know about performing off-axis experiments at these low energies. The near detector is designed to provide topological cross-sections of ~5% quality to determine the backgrounds to this search -- The Swiss contribution is shaping up.