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Research for the International Linear Collider Professor Andy White October 2005 What do we know now (2005)? What don’t we know now (2005)! - Why particles have mass - Whether all four forces merge at high energies - If we live in more than Four dimensions - What is the Dark Matter - What is the Dark Energy - …? Is there a Hiigs field that gives mass to particles? Contributions to the Higgs mass Produces an infinite result due to summation over momenta of particles in the circular loop. A possible cure? …add a contribution that cancels the bad contributions: But this requires new particles ! A better merging if SUSY is included! Many of our present questions should be answered at the Large Hadron Collider UTA is a member of the ATLAS Collaboration …but ATLAS discoveries will need have detailed follow up and verification before we know what the real nature of the new physics is! ILC - Accelerator Luminosity : 3.4x1034 cm-2s-1 (6000xLEP) ~ 90 – 1000 GeV Superconducting RF Technology 5 bunch trains/s 950 µs 199 ms 950 µs 2820 bunches 337 ns between collisions Physics rates e+e- qq 330/hr e+e- W+W- 930/hr e+e- tt 70/hr e+e- HX 17/hr Background rates e+e- qq 0.1 /Bunch Train e+e- X 200 /Bunch Train ILC - Physics Emphasize precision measurements – in a difficult environment – many multijet final states. ?? Optimizing the physics for 1 or 2 detectors?? σ(e+e-gZHH) = 0.3 fb •ZHH SiD Detector Solenoid ILC – Detector Requirements - Good momentum resolution e.g. for ZH with Z -> µµ - Vertex resolution for flavor tagging c/b - Good jet energy energy and jet-jet mass resolution - Good coverage for missing energy - Good separation of charged/photons/neutral clusters -> Good pattern recognition, two track separation Physics examples driving calorimeter design Higgs production e.g. e+ e- -> Z h Missing mass peak or bbar jets separate from WW, ZZ (in all jet modes) Higgs couplings e.g. - gtth from e+ e- -> tth -> WWbbbb -> qqqqbbbb ! - ghhh from e+ e- -> Zhh Higgs branching ratios h -> bb, WW*, cc, gg, Strong WW scattering: separation of e+e- -> WW -> qqqq e+e- -> ZZ -> qqqq and e+e- -> tt Physics examples driving calorimeter design -All of these critical physics studies demand: Efficient jet separation and reconstruction Excellent jet energy resolution Excellent jet-jet mass resolution + jet flavor tagging Plus… We need very good forward calorimetry for e.g. SUSY selectron studies, and… ability to find/reconstruct photons from secondary vertices e.g. from long-lived NLSP -> G Can we use a “traditional” approach to calorimetry? (using only energy measurements based on the calorimeter systems) 60%/E H. Videau 30%/E Target region for jet energy resolution Don’t underestimate the complexity! Digital Hadron Calorimetry Physics requirements emphasize segmentation/granularity (transverse AND longitudinal) over intrinsic energy resolution. - Depth 4 (not including ECal ~ 1) + tail-catcher(?) -Assuming PFlow: - sufficient segmentation (#channels) to allow efficient charged particle tracking. - for “digital” approach – sufficiently fine segmentation (#channels) to give linear energy vs. hits relation - efficient MIP detection (threshold, cell size) - intrinsic, single (neutral) hadron energy resolution must not degrade jet energy resolution. GEM-based Digital Calorimeter Concept GEM – production 140mm 70mm Hole profile Exposed kapton Copper edges GEM – operation -2100V ∆V ~400V ∆V ~400V 0V 305mm x 305mm layer Trace edge connector -> Fermilab 32 ch board Disc/DAQ under design by U.W. (10 x 10) – 4 active area = 96 channels First 30cm x 30cm 3M GEM foils Development of GEM sensitive layer Gas inlet/outlet (example) Absorber strong back Cathode layer Non-porous, double-sided adhesive strips Anode(pad) layer Fishing-line spacer schematic 3 mm 1 mm 1 mm 9-layer readout pc-board (NOT TO SCALE) GEM foils DHCAL/GEM Module concepts GEM layer slides into gap between absorber sheets Side plates alternate in adjacent modules Include part of absorber in GEM active layer - provides structural integrity “Window for Detector R&D 2004 2005 2006 2007 2008 GDE (Design) 2009 2010 (Construction) Technology Choice Acc. CDR TDR Start Global Lab. Done! Det. Detector Outline Documents CDRs LOIs Detector R&D Panel Detector R&D Phase Collaboration Forming Construction Tevatron SLAC B HERA LHC T2K Timeline of Beam Tests 2005 2006 2007 2008 2009 >2009 CALICE SiW ECAL OTHER ECALs CALICE TILE HCAL+TCMT CALICE DHCALs and others ILCD R&D, calibration Combined CALICE TILE Combined Calorimeters m, tracking, MDI, etc PFA and shower library Related Data Taking Phase 0: Prep. Phase I: Detector R&D, PFA development, Tech. Choice Phase II From Jae Yu Many challenging and exciting projects on Linear Collider R&D! -> Detector design -> Prototype construction/testing -> High speed electronics -> Computer simulations (need help!) -> Physics studies (need help!) [email protected] x22812 Room 241