1. 26/01/05A. Geiser, Discussion on T2K 1 Participation in T2K neutrino program? benefits, options, and opportunities nIntroduction nOutline of current questions in neutrino physics nThe T2K program nDetector and schedules nDESY-specific aspects nConclusions Achim Geiser ZEUS DESY group discussion on future opportunities 26. January 05

2. 26/01/05A. Geiser, Discussion on T2K 2 The T2K project 50 GeV p ~1 GeV

3. 26/01/05A. Geiser, Discussion on T2K 3 Assumptions on constraints nDESY contribution initially limited to manpower and resources as outlined in the HGF request nfurther contribution should be scalable both upwards and downwards, depending on resources and roadmap for DESY participation in ILC nneed long term future option nindividual DESY physicists cannot simultaneously participate in HERA and ILC and external activity (group can) -> external activity in addition to declining HERA activity/stepping up ILC activity

4. 26/01/05A. Geiser, Discussion on T2K 4 Current issues in neutrino physics nconservative assumption: neutrino oscillations are established! Super-K, SNO, KamLand + many others -> neutrinos have mass, (minimal) extension of Standard Model! nquark masses (6) and mixing parameters (4) are now all known; recently completed by CP violation parameters from Belle/Babar nout of the corresponding 10 mass and mixing parameters of the lepton sector (slide), only 7 are (partially) known: m e, m, m, m 2 12, 12 (solar), | m 2 23 |, 23 (atm) nremain to be measured: absolute mass scale (tritium beta decay, double beta decay) sign of m 2 23 mass hierarchy (slide), matter effects 13 ! (~equivalent to Vub) CP violation!!

5. 26/01/05A. Geiser, Discussion on T2K 5 Current issues in neutrino physics CP violation can only be measured if 13 /= 0 ! need 3-generation mixing! Sign of m 2 23 can only be measured if 13 /= 0 ! need e contribution! (matter effects) nleptonic CP violation might be able to explain baryon asymmetry in the universe (standard model instanton processes in Big Bang can turn lepton asymmetry into baryon asymmetry) quark sector CP violation cannot (too small!) measurement of 13 is very fundamental! T2K phase I ninterest of CP violation is obvious T2K phase II + neutrino factory

6. 26/01/05A. Geiser, Discussion on T2K 6 T2K (2009~) K2K (1999~2005?) Super-Kamiokande 250km J-PARC @JAERI CHOOZ excluded sin 2 2 13 Sensitivity on e appearance ~20times Neutrino physics at J-PARC Tokai-to-Kamioka (T2K) LBL experiment Off-axis sub-GeV beam from J- PARC 50GeV-PS ~3000 CC int./yr (w/o osc.) e appearance discovery disapp. precise meas. n5 year const. Start exp. in 2009. S Nagamiya, NP04, KEK, August 24, 2004

7. 26/01/05A. Geiser, Discussion on T2K 7 The T2K program nend of 2004: phase I finally approved! n2005-2008 prepare near detector, reequip Super-K (far detector) with full phototube density n(1. April?) 2009: start data taking (when they say april 1, they mean april 1) measure/limit 13 ! (best sensitivity worldwide) if /= 0, CP violation and matter effects can be large! improve measurements of sin 2 23 (=1 or not?) and m 2 23 standard neutrino physics with near detector nin parallel, prepare for phase 2 (start 20xx?): higher intensity beam (proton driver), intermediate detector, HK

8. 26/01/05A. Geiser, Discussion on T2K 8 Location of JAERI at Tokai Tokai Tsukuba S Nagamiya, NP04, KEK, August 24, 2004

9. 26/01/05A. Geiser, Discussion on T2K 9 Replies to Recommendations (2) Recommendation #3: The IAC strongly recommends that the neutrino oscillation experiment be brought into Phase I with additional supplementary funding. This would send a clear signal for international collaboration in this area. The neutrino project was approved for construction. S Nagamiya, NP04, KEK, August 24, 2004

10. 26/01/05A. Geiser, Discussion on T2K 10 Construction Schedule 1) Budget and Schedule S Nagamiya, NP04, KEK, August 24, 2004

11. 26/01/05A. Geiser, Discussion on T2K 11 Expected Beam Power 1) Budget and Schedule S Nagamiya, NP04, KEK, August 24, 2004

12. 26/01/05A. Geiser, Discussion on T2K 12 IAC, March 2004 2) Construction Status S Nagamiya, NP04, KEK, August 24, 2004

13. 26/01/05A. Geiser, Discussion on T2K 13 3 GeV Quadrupole Magnet 2) Construction Status S Nagamiya, NP04, KEK, August 24, 2004

14. 26/01/05A. Geiser, Discussion on T2K 14 Letters of Intent for 50 GeV Announce of LoI call : July 2002 Thirty LoIs were submitted by early 2003 Strangeness nuclear physics 7 Nuclear/hadron physics7 Kaon decay physics 4 Muon physics3 Neutrino physics1 Future facilities8 478 physicists with 2/3 from outside Japan. Asian participation is still few. Call for proposals: Most likely, within half(?) a year, if no further delay is observed for the 50 GeV construction. 4) Letters of Intent S Nagamiya, NP04, KEK, August 24, 2004

15. 26/01/05A. Geiser, Discussion on T2K 15 Timeline for 50 GeV Proposals S Nagamiya, NP04, KEK, August 24, 2004

16. 26/01/05A. Geiser, Discussion on T2K 16 From K2K to T2K T2K = Tokai to Kamioka (not yet an official name) Best fit Flux ( ) at J-PARC 50 GeV PS > 100 x Flux ( ) at KEK 12 GeV PS With oscillation Without oscillation Data since 1999 K2K = KEK to Kamioka 108 events observed (151 events expected without any oscillations) 99.99% confident that carries a finite mass. 3) Recent News in Sciences S Nagamiya, NP04, KEK, August 24, 2004

17. 26/01/05A. Geiser, Discussion on T2K 17 e appearance. nOvercome the background and correctly estimate the remaining background. sin 2 2e =0.05, m 2 =3×10 -3 eV 2 mostly 0 mostly from decay LOI

18. 26/01/05A. Geiser, Discussion on T2K 18 Conceptual Off-Axis 280m Detector Magnet (and side MRD) Electron calorimeter Fine Grained detector w/ or w/o water target Scintillator Tracker (TPC or chambers) Iron shield for -ID

19. 26/01/05A. Geiser, Discussion on T2K 19 UA1 Magnet n7.64(L)× 6.116(H)× 5.596(W) B=0.67T (UA1), 0.4T(NOMAD), 0.2T (T2K for power<0.6MW) nNOMAD experiments

20. 26/01/05A. Geiser, Discussion on T2K 20 Instrumenting the iron C are made of plates of iron 4.8 cm thick Gap of 1.7 cm between plates It is possible to insert scintillators in the gaps (1 complete layer ~ 90 m2) (extruded scintillators with fibers?) For UA1 = hadron calorimeter For T2K = muon range detector

21. 26/01/05A. Geiser, Discussion on T2K 21 Full Active target detector nSciBar-like to measure the exclusive final states.

22. 26/01/05A. Geiser, Discussion on T2K 22 T2K Interim Collaboration Agreement and Interim MoU for the Common Project which are under discussion in the IBR K. Nakamura, T2K collaboration meeting, 24.8.04

23. 26/01/05A. Geiser, Discussion on T2K 23 Interim Agreement on International Collaboration K. Nakamura, T2K collaboration meeting, 24.8.04 nT2K Collaboration does not have a Collaboration Agreement yet. nIn the formal CA, we (Spokesperson + KEK Representative) wish to specify contributions from each participating Institution/Country/Region to the Experiment. nUntil the funding situation of most of the participating Institution/Country/Region becomes clear, we wish to proceed with an Interim Agreement. nUntil the formal CA is signed, the IBR (International Board of Representatives) functions as the Executive Committee. nOrganization, Institutional Responsibilities, Membership, etc. will be defined.

24. 26/01/05A. Geiser, Discussion on T2K 24 T2K Interim Board of Representatives nSpokesperson K. Nishikawa nConstruction group representative T. Kobayashi nNational / Regional representatives CanadaA. Konaka, J.M. Poutissou ItalyM. Mezzeto FranceF. Pierre KoreaS.B. Kim PolandD. Kielczewska RussiaY. Kudenko Spain E. Fernandes SwitzerlandA. Blondel UK D. Wark USAG. Beir, C.K. Jung*, H. Sobel nKEK representative K. Nakamura nICRR representative Y. Suzuki K. Nakamura, T2K collaboration meeting, 24.8.04

25. 26/01/05A. Geiser, Discussion on T2K 25 Common Project and Common Fund for Facilities Related to Neutrino Beam and Near Detector nAs one of the host institutes of the T2K Experiment, KEK is responsible for the civil construction of the facilities related to the neutrino beam and the near detectors. nThe construction of the neutrino beam line and the near detectors including part of the beam extraction system is defined as the Common Project of the T2K Collaboration. nEach collaborating Institute/Country/Region is expected to contribute to the Common Project appropriately. nContributions to the Common Project will be made in two ways: In-kind contribution to supply engineering work and/or equipments cash contribution to the Common Fund nKEK as a host institute will exchange an Interim MoU with each contributing Institution/Funding Agency with regard to funding request for the contribution to the Common Project. nWhen funding is allocated, the Interim MoU will be replaced with the MoU between KEK and the contributing Institution/Funding Agency.

26. 26/01/05A. Geiser, Discussion on T2K 26 potential DESY participation? ndisclaimer: the following is an example for a hypothetical scenario made up by me, not yet discussed with the DESY management nor with the T2K collaboration nphase 0: 2005/6? main hardware/software/analysis activity: HERA convergence towards decision on external DESY participation preparation of potential bilateral german-japanese agreements discussion on agreement at European level to become part of a European hub for infrastructure (hardware, test beams, meetings) and computing/analysis for test beam and physics data collaboration agreement on detector tasks and access to far detector data, in-kind contributions? (beam-line elements (HERA), detector parts (ZEUS)) formally join T2K collaboration in 2006? nphase 1: 2007/8? main analysis activity: HERA work on hardware/software contribution to T2K detector construction activities according to agreement electron test beam activities, including support for other European groups preparation of online and monitoring software preparation of analysis software

27. 26/01/05A. Geiser, Discussion on T2K 27 potential DESY participation? nphase 2: 2009-final ILC approval? start of T2K data taking shift of analysis activity HERA -> T2K hardware activity towards intermediate+far detectors? running in of near detector participation in data taking shifts start European or European/US analysis activity! (attract students) prepare participation to T2K stage 2 (e.g. intermediate detector, HK) in parallel after end of HERA analysis: participate in ILC+detector design activities (e.g. T2K diploma students -> ILC PhD students) nphase 3: ILC approval-ILC startup? main analysis activity: T2K rescale hardware/software contribution to T2K for compatibility with ILC+detector plans data analysis! (oscillations + many standard physics topics) define scale of participation to T2K phase 2 hardware depending on available resources continue role as infrastructure provider in any case (=minimum involvement)

28. 26/01/05A. Geiser, Discussion on T2K 28 Conclusions nDESY participation in T2K would offer great physics opportunities (attract students + postdocs) fit transition time between end of HERA analysis and start of ILC analysis offer opportunities to collaborate with German and European partners in a fully international project and serve as a German or maybe even European Hub offer opportunities for application of expertise in particle physics analysis, detectors and beam line elements (+ in-kind contributions from ending HERA program??) allow to participate with initially limited resources allow to scale future hardware commitments according to ILC developments offer excellent long term perspectives, if wished, via an intermediate detector and a Megaton far detector towards a neutrino factory nIf participation to an external project is considered at all, this option ideally matches all the requirements

29. 26/01/05A. Geiser, Discussion on T2K 29