John Womersley

Experiments and Detectors Experiments and Detectors for Future Hadron Collidersfor Future Hadron Colliders

John Womersley

International Workshop on Future Hadron CollidersFermilab

October 2003

John Womersley

OutlineOutline

• 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”

John Womersley

Physics Simulations Physics Simulations Mangano

John Womersley

Two R&D tracks: 1Two 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

John Womersley

SLHC AcceleratorSLHC Accelerator

• Work underway – In context of LARP in US – Only Intersection Region upgrades are “on the table”

Peggs

John Womersley

SLHC TrackingSLHC 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

John Womersley

Calorimetry at SLHCCalorimetry 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

John Womersley

Muon measurement at SLHCMuon measurement at SLHC

• Critical Issues:• Rate demand on tracking & trigger technologies

– Occupancy vs. pattern recognition– Ghost tracks & Track Matching between ID & Muons

– Trigger PT – 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

John Womersley

SLHC Trigger and DAQSLHC 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

John Womersley

VLHC scopeVLHC 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

John Womersley

Two R&D Tracks: 2Two 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…

John Womersley

VLHC accelerator R&DVLHC 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

John Womersley

John Womersley

Tracker/muon issues for VLHCTracker/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 ~ /BL2

– 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”)?

DenisovHauser

John Womersley

Calorimetry at VLHCCalorimetry 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 ET, 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

John Womersley

VLHC probes the “deep unknown”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?

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 TeVA new interactionWe parameterize it as a “Higgs”

ŝ = 20 TeV?see the underlying dynamicsof the WW interaction

“Deep inelastic WW scattering”

John Womersley

Political next stepsPolitical 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

John Womersley

Selling acceleratorsSelling 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

John Womersley

Springboards for discussionSpringboards 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

John Womersley

Continued …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?