1. John Womersley Experiments and Detectors for Future Hadron Colliders John Womersley International Workshop on Future Hadron Colliders Fermilab October 2003

2. John Womersley Outline The organizers asked me to start to list the work that needs to be done –Opportunities –Problems with the idea that we follow up at future workshops I will summarize –Work needed on Detector and Accelerator R&D –Work needed on the Political Context –Importance emphasized by many speakers End with some “springboards for discussion”

3. John Womersley Physics Simulations Mangano

4. John Womersley Two R&D tracks: 1 Targeted R&D for SLHC –Environment can be predicted –Requirements can be specified –Challenges are straightforward to enumerate –Extrapolation from present techniques is unavoidable given the timescale –Organized (funded?) through CERN, ATLAS and CMS

5. John Womersley SLHC Accelerator Work underway –In context of LARP in US –Only Intersection Region upgrades are “on the table” Peggs

6. John Womersley SLHC Tracking Challenges: –radiation damage –occupancy Move “known” techniques further out in radius Need new technology for innermost layers (r < 20 cm) Most likely entire CMS and ATLAS trackers will need replacement Projects are now underway –RD50 and RD42 –Better understand radiation damage, materials and defects –Explore new materials –Electronics issues –Device engineering, integration issues Demina

7. John Womersley Calorimetry at SLHC Rate Radiation damage Activation Both ATLAS and CMS –Barrels ~ OK –Endcaps need replacement(?) –Technology exists – but not fully worked out –How much pseudorapidity coverage is needed –Physics question: forward jet tagging Freeman

8. John Womersley Muon measurement at SLHC Critical Issues: Rate demand on tracking & trigger technologies –Occupancy vs. pattern recognition –Ghost tracks & Track Matching between ID & Muons –Trigger P T – resolution & Rate –Stability of chamber parameters under rate –Beam crossing timing –Longevity –Chambers & Electronics (Rad Hard & SE Upsets) Shielding Looks as if both ATLAS and CMS will need to replace barrel drift tubes –Gaseous detectors are the only way(?) to cover the area needed –Technology candidates exist Taylor

9. John Womersley SLHC Trigger and DAQ Trigger rates ~ OK R&D needed on: –New First Level Triggers for –12.5 ns crossings –new sub-detectors –increased pile-up & occupancy –Data links –HLT/DAQ networks –'Complexity handling' Development of commodity computing –Helps us a great deal, but will it save us? Can we learn from management techniques used in other big, complex technical integration projects? Lankford

10. John Womersley VLHC scope Are we ready to define energy, luminosity for a preferred VLHC? –Probably not Should we explore additional energy, luminosity scenarios? –We have one “worked out” case from Peter and collaborators –Explore others to better understand parameter space? What is the process to define what we will need/want? What is the balance between having a cast-iron physics case and making an appeal to “throw deep,” to the excitement of a bold technological step? –e.g. Big telescopes

11. John Womersley Two R&D Tracks: 2 “Blue sky” R&D for future machines Importance of devoting significant resources to this second kind of R&D stressed by many speakers –the requirements cannot be precisely specified –B tagging? –Pseudorapidity coverage? –Need to think of enabling technologies rather than developing devices for particular tasks –Not limited to VLHC application –e.g. large, cheap detectors help neutrino experiments too –Extrapolation from present techniques may be very wrong –Think outside the box –Organized – how? Funded – how? The “good news” is that, if detector issues of SLHC are solved, the challenges to go on to VLHC seem (to me) relatively tractable –  10 in energy is “easier” than  10 in luminosity –Except for the cost of a new tunnel and new magnets…

12. John Womersley VLHC accelerator R&D R&D for –tunneling –vacuum –both high and low field magnets –Very high fields (> 12 T) “may not be the best solution” –Synchrotron radiation issues –Need to demonstrate feasibility, reduce cost Limon

13. John Womersley

14. Tracker/muon issues for VLHC Radiation dose, number of pileup tracks and pileup energy are all much more dependent on luminosity than on  s –Specific challenge for VLHC is measuring higher energy physics objects (20 TeV muons, for example) Tracking momentum resolutions ~  /BL 2 –High field –Precision measurements –Large detectors Detectors that see only straight tracks or tracks coming from the “inside” –Otherwise muon triggers get swamped by backgrounds –remember Nikolai Mokhov’s pictures Affordable, fast, large-area detectors (a “better RPC”)? Denisov Hauser

15. John Womersley Calorimetry at VLHC “Easier” than tracking –Size ~ ln s, and resolution only gets better with energy –Specific challenge for VLHC is the desire to cover very large  (huge radiation dose) Understanding of pileup, missing E T, jet resolutions (QCD effects vs. energy flow…) R&D on: Cerenkov calorimetry (quartz or gas) –Rad hard and fast New photon detectors, rad hard, small, cheap New scintillator materials Are there totally new detector ideas? Freeman

16. John Womersley VLHC probes the “deep unknown” A very large hadron collider was the only facility discussed (e.g. at Snowmass 2001) able to go so far beyond the energy regime we understand that we have no idea what physics we will see –Once upon a time, this would have been exciting, compelling, reason enough to build it –Now it is seen as a liability Shouldn’t we try to turn this perception around?

17. John Womersley An LHC experiment: Study the new interaction with precision measurements of Higgs properties at a LC – yes, good –but then… We will want to study the new interaction at much higher energies: a (V)VLHC experiment:  ŝ = 1 TeV A new interaction We parameterize it as a “Higgs”  ŝ = 20 TeV? see the underlying dynamics of the WW interaction “Deep inelastic WW scattering”

18. John Womersley Political next steps 1.Need to lay the groundwork for future big accelerator projects –Ten years ago to the month, the future of US high energy physics was cancelled. –We have not yet emerged from that shadow –At least in the U.S., the case for any future accelerator is far from made –We have to work on this: no one else will! 2.Advocate, defend, promote R&D on both accelerator and detector development for such projects 3.Support the most rapid possible progress on the Linear Collider Why? Because to do otherwise would undermine goal 1 Because we want a world that can support more than one big high-energy physics project Because it will do good physics

19. John Womersley Selling accelerators Accelerators are the key to understanding this weird and wonderful universe that we inhabit Only they can provide the –Controlled conditions –Known particle species –High rates –High energies that we need to make sense of cosmological observations Recent progress in astroparticle physics and cosmology strengthens the case for new accelerators, it does not weaken it –no shame in exploiting public interest in these discoveries The public will relate to –the unknown –the cosmos –big science questions – but also to ambitious technical projects

20. John Womersley Springboards for discussion Does SLHC+VLHC in one room make sense? Are we one community? VLHC Physics Do we agree that a staged VLHC is desirable? –If so, how do we narrow down the parameters of stage I? –When? Do we really have the simulation tools that we need? –Is there a catalogue? Benchmark processes to “cover the bases” for signals? Are we ready for (do we need) a toy detector model? Developing the physics case –“NASA model” of multiple missions within a big theme

21. John Womersley Continued … R&D How can we promote support for “generic” detector and magnet R&D? –Within this/other laboratories –FNAL long range planning effort? Can we come up with a short list of such projects that should be given the highest priority? –Use this workshop to “legitimize” them somehow?