Cherenkov Tracking Calorimeters D. Casper University of California, Irvine

June 24, 2005D. Casper, UC Irvine2 Outline  Overview  Basic performance around 1 GeV  Neutrino response

June 24, 2005D. Casper, UC Irvine3 Acknowledgements and Caveats  Some work done together with: J. Dunmore, C. Regis (UCI) J. Dunmore, C. Regis (UCI) J. Burguet-Castell, E. Couce, J.J. Gomez-Cadenas, P. Hernandez (Valencia) J. Burguet-Castell, E. Couce, J.J. Gomez-Cadenas, P. Hernandez (Valencia)  Thanks to: M. Fechner (Saclay) M. Fechner (Saclay) Super-Kamiokande and T2K Collaborations Super-Kamiokande and T2K Collaborations  Disclaimers Not “official” results of any experiment except where noted Not “official” results of any experiment except where noted Intended as a generic overview Intended as a generic overview Hybrid (Cherenkov/Scintillation) detectors not considered explicitly Hybrid (Cherenkov/Scintillation) detectors not considered explicitly

June 24, 2005D. Casper, UC Irvine4 Motivations  Fully active target Inexpensive detecting medium Inexpensive detecting medium  Surface instrumentation PMT cost scales like (Mass) 2/3 PMT cost scales like (Mass) 2/3  Long attenuation length Size limited primarily by cavern excavation Size limited primarily by cavern excavation  Originally designed for proton decay searches

June 24, 2005D. Casper, UC Irvine5 What Is Measured  PMT timing Coincidence trigger Coincidence trigger Vertex position Vertex position Delayed coincidence Delayed coincidence  e decay  e decay Nuclear de-excitationNuclear de-excitation Neutron captureNeutron capture  Cherenkov rings Particle directions from angle constraint Particle directions from angle constraint Showering/Non-showering topology for particle ID Showering/Non-showering topology for particle ID  PMT pulse heights Energies from calorimetry and/or range Energies from calorimetry and/or range

June 24, 2005D. Casper, UC Irvine6 Cherenkov Detectors  First Generation ( ) IMB (3.3 kton, 1%  4.5%) IMB (3.3 kton, 1%  4.5%) Kamiokande (0.78 – 1.1 kton, 20%) Kamiokande (0.78 – 1.1 kton, 20%) Harvard-Purdue-Wisconsin Harvard-Purdue-Wisconsin  Second Generation (1996-Present) Super-Kamiokande (22.5 kton, 40%) Super-Kamiokande (22.5 kton, 40%) SNO (1.0 kton, 55%) SNO (1.0 kton, 55%) K2K (0.025 kton, 40%) K2K (0.025 kton, 40%)  Next Generation (ca ) T2K 2km (0.025 kton, 40%) T2K 2km (0.025 kton, 40%) Hyper-Kamiokande (~1 Mton, 40%) Hyper-Kamiokande (~1 Mton, 40%) etc… etc…

June 24, 2005D. Casper, UC Irvine7 Basic Performance near 1 GeV  Vertex resolution: ~20-30 cm Challenge to control the fiducial volume of a small detector Challenge to control the fiducial volume of a small detector  Direction resolution: 2-3° Negligible compared to neutrino-lepton scattering angle Negligible compared to neutrino-lepton scattering angle  e/  mis-ID: ~0.4%/  (  %photocathode) For equal e/  purity and efficiency For equal e/  purity and efficiency Verified in test beam Verified in test beam  Energy resolution: ~2%/(  E vis ) 1/2 Additional energy scale uncertainty: 2-3% Additional energy scale uncertainty: 2-3%  Muon decay efficiency: ~95% (  + ), ~75% (   ) 22%   capture probability in water 22%   capture probability in water

June 24, 2005D. Casper, UC Irvine8 Neutrino Response   Response (1-ring mu-like sample) Super-beam disappearance signal Super-beam disappearance signal Super-beam appearance background Super-beam appearance background Beta-beam appearance signal Beta-beam appearance signal  e Response (1-ring e-like sample) Super-beam appearance signal Super-beam appearance signal Beta-beam disappearance signal Beta-beam disappearance signal Beta-beam appearance background Beta-beam appearance background

June 24, 2005D. Casper, UC Irvine9 Does Size Matter?  For a given photo-cathode coverage, greater pixelization helps reduce  0  e For a given photo-cathode coverage, a larger detector performs better at e/mu and e/  0 separation For a given photo-cathode coverage, a larger detector performs better at e/mu and e/  0 separation

June 24, 2005D. Casper, UC Irvine10 Cross-Sections

June 24, 2005D. Casper, UC Irvine11 CCQE Efficiency Loss of partially contained  Fully-contained  CCQE 1-ring mu-like efficiency Losses to  0 cuts Fully-contained e CCQE 1-ring e-like efficiency

June 24, 2005D. Casper, UC Irvine12 Signal and Backgrounds 1-ring  -like sample 1-ring e-like sample

June 24, 2005D. Casper, UC Irvine13 Contamination vs. Smearing 1-ring  -like sample 1-ring e-like sample

June 24, 2005D. Casper, UC Irvine14 CC Energy Transfer Matrices CCQE CC1  CC Other

June 24, 2005D. Casper, UC Irvine15 Higher Energies  Possible to use hadronic calorimetry at higher energies Does not help with particle ID Does not help with particle ID  Possible to identify clean sample of high- energy muons from interactions outside the detector “Upward-going muons” “Upward-going muons” May be able to say something about energy using angle(?) May be able to say something about energy using angle(?)

June 24, 2005D. Casper, UC Irvine16 Conclusions  A very mature and powerful technology  Backgrounds to low-medium energy super-beams or beta beams are fairly manageable Depends on details of beam, baseline, etc. Depends on details of beam, baseline, etc.  Energies above GeV create difficulties May be mitigated by migration May be mitigated by migration