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`Your Vision of a Future Tevatron Program’ ( request from Chris )

`Your Vision of a Future Tevatron Program’ ( request from Chris ). Henry Frisch University of Chicago. Patrick Huber. I. Run the Tevatron Until We Are Sure We Don’t Need It.

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`Your Vision of a Future Tevatron Program’ ( request from Chris )

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  1. `Your Vision of a Future Tevatron Program’ (request from Chris) Henry Frisch University of Chicago Patrick Huber Fermilab 3/4/2010

  2. I. Run the Tevatron Until We Are Sure We Don’t Need It • There are key precision measurements that it will be a very long time, if ever, before they are done better at the LHC than at the Tevatron – e.g. the W mass and the top quark mass. • Even if the LHC is able to measure these more precisely, the systematics of the measurements at the LHC and the Tevatron will be quite different- there is a good chance that the tension between the EWK precision fits and the LEP limit on the Higgs mass will endure, and being sure that there is no problem in MW or Mtop is critical. • There are many models that have light new physics- the Tevatron is a better match to MET ~ MW/4 and light masses (few GeV to EWK scale) for track-based triggering and soft electron reconstruction, among other soft (low Pt) things. • We have finally entered the realm of diboson and Higgs cross-sections- still many signatures to explore. The SM Higgs is only one of many possibilities, e.g.- and tools are still getting better. Why quit now? Fermilab 3/4/2010

  3. II. Make adiabatic improvements and necessary replacements/upgrades • Systematic program to get detector efficiencies to PRL (not to tape) up to 90% (`hammering down highest nails’)- many small nagging losses. • Make tests of luminosity leveling- opposition was from b-physics, but would help in quality of high-Pt data, analysis, and (I still believe, but could be wrong) efficiency. • I don’t know about silicon lifetime- need to ask experts- I think other sub-systems are ok (e.g. CEM goes down slowly but steadily, COT and magnet seem to be holding up) Fermilab 3/4/2010

  4. III. Assign technical staff to run the detectors instead of constant shuffling of responsibilities • Heard often that `there aren’t enough people to run the detectors’. • This is true in the present model, which is mind-blowingly inefficient. In the present model, institutions are still responsible for sub-systems built years (decades in some cases) earlier. Maintaining these systems is neither interesting nor easy to do well- yet we persist at it. Not surprisingly, it’s hard to find enough people to do it. The ones we do find are completely unskilled and are short-term. • The lab needs to make a new model, the `John Roof’ model, in which permanent staff are assigned to run, maintain, and improve the operation of the detectors. This is possible- it would only take a management decision that this is a priority. Fermilab 3/4/2010

  5. IV. Make qualitative improvements in capability (i.e. non-adiabatic) • EXAMPLES (these need evaluation by collaboration godparent committees or equiv.- these are ones I know a little about, probably good others) • New silicon systems with better spatial resolution (cancelled by previous management) • New TDC’s for the COT for faster readout (cancelled by previous management), less deadtime (more b-physics data) • 3-10-psec TOF for K-pi separation for quark-flavor identification (e.g. ttbar -> e nu b bbar c sbar). • New SVT track-based trigger. • Build on ILC detector development advances- incorporate them into the Tevatron program. (takes careful evaluation) Fermilab 3/4/2010

  6. What follows is completely ignorant, and may be much too late, and in any case impossible to turn the ship around to given the momentum (inertia), but in the abstract still seems to me to be the right answer: so, be forgiving (Chris asked for `vision’) Fermilab 3/4/2010

  7. IV. Upgrade the pbar source • I don’t know much about this- but there are many exceptionally talented folks at the lab and elsewhere who do. If there were serious support for this, how much could be gained? (again, question of money, talent, and commitment- I just have no idea of the curve of gain vs money and time, e.g. I would ask Paul Derwent, Rol Johnson, and Chuck Ankenbrandt, for starters.) Fermilab 3/4/2010

  8. V. Go for USA as Number 1 Again(we owned the podium- want it back). Go for the energy frontier- that’s where the big questions will be answered, if at all. Go back to 1984 pbar workshop at UC, and (one) start of the SSC tragedy. Pbarp at 1033 and 42 TeV reaches 21 TeV in q-qbar vs 7.8 for pp at 1034. Fermilab 3/4/2010

  9. VI. Followed by a Muon Collider • Long-term goal of the lab should be a muon collider, IMHO (15-20 years out?) • But we cannot afford a long gap of a weak or narrow program in the interim- neutrino program is not broad enough, both in opportunities for young folks and in basic questions being asked, to support the effort until we get to the next step. • And it’s a long ways to a muon collider (I’m no expert- Rol, who is, says not and is actually doing something about it, and I don’t know, but would be nice to be on a path that seems broader and richer while we develop one. Fermilab 3/4/2010

  10. Back to IV. Pbar-p at 42 TeV • Has to be innovative, much lighter weight than SSC, ILC, or LHC. • Has continuity with Tevatron program- upgrading pbar source, build a new detector with ILC technologies (`CD0F’?), 4th-gen detector. • Not a new proposal- 1984 Workshop, work by Ernie Malamud, others- just not taken seriously. • Requires robust, relatively simple (no pushing boundaries) magnet design. Much simpler than LHC 2-in-1 high-field magnets. • Probably requires horizontal drilling (not tunneling) of small-diameter tunnel and robotic installation. • Local opposition existed for Fermilab- not guaranteed, but was overcome then. (I think this is a red herring). • Present political climate receptive to `We want to be Number 1 again’ argument- not to Theta13 muttering. Fermilab 3/4/2010

  11. THE END “You could be up to your belly-buttons in (SUSY) and not know it..”- C. Prescott

  12. BACKUP SLIDES

  13. Precision Measurements of MW and MTop • Much as the case for Babar was made on the closing of the CKM matrix, one can make the case that closing the MW -MTop-MHiggs triangle is an essential test of the SM. • All 3 should be measured at the LHC- suppose the current central values hold up, and the triangle doesn’t close (or no H found!). Most likely explanation is that precision MW orMTop is wrong. • The systematics at the Tevatron are completely different from those at the LHC- much less material, known detectors, qbarq instead of gg, # of interactions, quieter events (for MW). • =>Prudent thing to do is don’t shut off until we see MW -MTop-MHiggs works. • Remains to be proven that the LHC can measure MW andMTop better than the Tevatron (maybe eventually, but not soon is my guess)

  14. Low-mass/low met BSM LHC has much more reach- but there may be regions of rel. soft things (e.g. met~20) that will not be top priority at CERN and where light new physics can hide. LHC is not optimum for this physics- Tevatron complements it well. This is physics that may not get done if not at Fermilab, and has discovery potential. • Triggering at EWK-scale values of MET (M_W/4)- interesting mass region based on MW-mtop, models of light objects at low cross-sections. • Identification of soft electrons and taus from new light objects in EWK events (too much material, multiple interactions)- region not yet explored well Fermilab 3/4/2010

  15. Tevatron aspects complementary to LHC strengths to compare capabilities • Obvious ones (pbar-p,..) • Electron, photon, tau ID has much less material- ultimate MW, H->taus,? • Tau-ID; photon/pizero separation (shower max) • Triggering at met~20GeV • Triggering on b, c quarks (SVT)- also (?) hyperons,… Fraction of a radiation length traversed by leptons from W decay (CDF Wmass analysis)- << 1 X0

  16. The attraction of hardware upgrades (this is a little over the top- ignore it if you want to, please) • Could even imagine bigger upgrades- e.g. may want to distinguish W->csbar from udbar, b from bbar in top decays, identify jet parents,.. • Outfit one of the 2 detectors with particle Id- e.g. TOF with s <= 1 psec: Collect signal here Incoming particle makes light in window: Micro-channel Plate/Cherenkov Fast Timing Module

  17. Geometry for a Collider Detector “r” is expensive- need a thin segmented detector 2” by 2” MCP’s Beam Axis Coil Fermilab 3/4/2010

  18. Summary • Tevatron running well – expect >= 1.5-2 fb-1/yr/expt of all goes well (could even be somewhat better- there are more pbars). • Experiments running pretty well and producing lots of hands-on and minds-on opportunities (lots of room for new ideas, analyses, and hardware upgrades (great for students!) • Doubling time for precision measurements isn’t set by Lum- set by learning. Typical time constant ~ one grad student/postdoc. • Precision measurements- MW, Mtop, Bs Mixing, B states- MW and Mtop systematics statisics-limited • Can make a strong argument thatpbar-p at 2 TeV is the best place to look for light SUSY, light Higgs,…; as met at EWK scale, (MW/2, Mtop/4) doesn’t scale with mass, root-s, and tau’s (maybe b’s) are better due to lower mass in detector, and SVT and L1 tracking triggers, • All of which implies keep the Tevatron running until we know that we don’t need it (and keep Fermilab strong for the ILC bid too!) Fermilab 3/4/2010

  19. A real CDF Top Quark Event T-Tbar -> W+bW-bbar Fit t0 (start) from all tracks Measure transit time here (stop) W->charm sbar B-quark T-quark->W+bquark T-quark->W+bquark B-quark TRIDENT Cal. Energy From electron W->electron+neutrino Fermilab 3/4/2010 Can we follow the color flow through kaons, charm, bottom? TOF!

  20. Peak Lum of 3E32 40-50 pb-1/wk times 40 weeks/yr = 2 fb-1/year delivered per expt- There are more pbars even now. Peak lum problem =>Luminosity leveling? BUT: don’t focus on big improvements- steady improving X running=>smarts

  21. The Learning Curve at a Hadron Collider (tL) Take a systematics-dominated measurement: e.g. the W mass. Dec 1994 (16 yrs ago)- `Here Be Dragons’ Slide: remarkable how precise one can do at the Tevatron (MW,Mtop, Bs mixing, …)- but has taken a long time- like any other precision measurements requires a learning process of techniques, details, detector upgrades…. Theorists too(SM) Electron+ Electron- Fermilab 3/4/2010

  22. A real CDF Top Quark Event T-Tbar -> W+bW-bbar Fit t0 (start) from all tracks Measure transit time here (stop) W->charm sbar B-quark T-quark->W+bquark T-quark->W+bquark B-quark TRIDENT Cal. Energy From electron W->electron+neutrino Fermilab 3/4/2010 Follow the color flow!

  23. Luminosity vs Time Run II CDF Run II So Far Run II Run II Delivered Lum D0 (CDF+D0)/2* Xmas week Note pattern- integral grows when you don’t stop, with increasing slope *(Protons are smaller on this side (joke)) > 40 pb-1/wk/expt Fermilab 3/4/2010

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