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

Fermilab 3/4/2010 1

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

ChrisChris))Henry FrischHenry FrischUniversity of ChicagoUniversity of Chicago

Patrick Huber

Fermilab 3/4/2010 2

I. Run the Tevatron I. Run the Tevatron Until Until We Are SureWe Are Sure We Don’t Need We Don’t Need

ItIt1. 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.

2. 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.

3. 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.

4. 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 II. Make adiabatic improvements and improvements and

necessary necessary replacements/upgrades replacements/upgrades

1. Systematic program to get detector efficiencies to PRL (not to tape) up to 90% (`hammering down highest nails’)- many small nagging losses.

2. 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.

3. 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 III. Assign technical staff to run the detectors instead of run the detectors instead of

constant shuffling of constant shuffling of responsibilities responsibilities 1. 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 IV. Make qualitative improvements in capability improvements in capability

(i.e. non-adiabatic) (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)

1. New silicon systems with better spatial resolution (cancelled by previous management)

2. New TDC’s for the COT for faster readout (cancelled by previous management), less deadtime (more b-physics data)

3. 3-10-psec TOF for K-pi separation for quark-flavor identification (e.g. ttbar -> e nu b bbar c sbar).

4. 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 sourceIV. Upgrade the pbar source

1. 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 V. Go for USA as Number 1 AgainAgain

(we owned the podium- want it (we owned the podium- want it back).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 VI. Followed by a Muon ColliderCollider

• 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 Back to IV. Pbar-p at 42 TeVTeV

1. Has to be innovative, much lighter weight than SSC, ILC, or LHC.

2. Has continuity with Tevatron program- upgrading pbar source, build a new detector with ILC technologies (`CD0F’?), 4th-gen detector.

3. Not a new proposal- 1984 Workshop, work by Ernie Malamud, others- just not taken seriously.

4. Requires robust, relatively simple (no pushing boundaries) magnet design. Much simpler than LHC 2-in-1 high-field magnets.

5. Probably requires horizontal drilling (not tunneling) of small-diameter tunnel and robotic installation.

6. Local opposition existed for Fermilab- not guaranteed, but was overcome then. (I think this is a red herring).

7. Present political climate receptive to `We want to be Number 1 again’ argument- not to Theta13 muttering.

11

THE ENDTHE END

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

12

BACKUP BACKUP SLIDESSLIDES

13

Precision Measurements Precision Measurements of Mof MW W and and MMTopTop

Much as the case for Babar was made on the closing of the Much as the case for Babar was made on the closing of the CKM matrix, one can make the case that closing the MCKM matrix, one can make the case that closing the MW W --

MMTopTop-M-MHiggsHiggs triangle is an essential test of the SM. triangle is an essential test of the SM. All 3 should be measured at the LHC- suppose the current All 3 should be measured at the LHC- suppose the current

central values hold up, and the triangle doesn’t close (or no H central values hold up, and the triangle doesn’t close (or no H found!). Most likely explanation is that precision Mfound!). Most likely explanation is that precision MWW or or MMTop Top is is wrong. wrong.

The systematics at the Tevatron are completely different from The systematics at the Tevatron are completely different from those at the LHC- much less material, known detectors, those at the LHC- much less material, known detectors, qbarq instead of gg, # of interactions, quieter events (for Mqbarq instead of gg, # of interactions, quieter events (for MW).W).

=>Prudent thing to do is don’t shut off until we see M=>Prudent thing to do is don’t shut off until we see MW W -- MMTopTop--MMHiggsHiggs works. works.

Remains to be proven that the LHC can measure MRemains to be proven that the LHC can measure MW W andand MMTop Top better than the Tevatron (maybe eventually, but not soon is better than the Tevatron (maybe eventually, but not soon is my guess)my guess)


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.1. 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.

2. Identification of soft electrons and taus from new light objects in EWK events (too much material, multiple interactions)- region not yet explored well

15

Tevatron aspects complementary to LHC strengths to compare

capabilities Obvious ones (pbar-Obvious ones (pbar-

p,..)p,..) Electron, photon, tau Electron, photon, tau

ID has much less ID has much less material- ultimate Mmaterial- ultimate MWW, , H->taus,?H->taus,?

Tau-ID; photon/pizero Tau-ID; photon/pizero separation (shower separation (shower max)max)

Triggering at Triggering at met~20GeVmet~20GeV

Triggering on b, c Triggering on b, c quarks (SVT)- also (?) quarks (SVT)- also (?) hyperons,…hyperons,…

Fraction of a radiation length traversed by leptons from W decay (CDF Wmass analysis)- << 1 X0

16

The attraction of hardware upgrades

Could even Could even imagine bigger imagine bigger upgrades- e.g. may upgrades- e.g. may want to distinguish want to distinguish W->csbar from W->csbar from udbar, b from bbar udbar, b from bbar in top decays, in top decays, identify jet identify jet parents,..parents,..

Outfit one of the 2 Outfit one of the 2 detectors with detectors with particle Id- e.g. particle Id- e.g. TOF with TOF with <= 1 <= 1 psec: psec:

(this is a little over the top- ignore it if you want to, please)

Micro-channel Plate/Cherenkov Fast Timing Module

Incoming particle makes light in window:

Collect signal here


Geometry for a Collider Geometry for a Collider DetectorDetector

““r” is expensive- need a thin r” is expensive- need a thin segmented detectorsegmented detector

Coil

2” by 2” MCP’s

Beam Axis


SummarySummary1. Tevatron running well – expect >= 1.5-2 fb-1/yr/expt of all

goes well (could even be somewhat better- there are more pbars).

2. 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!)

3. Doubling time for precision measurements isn’t set by Lum- set by learning. Typical time constant ~ one grad student/postdoc.

4. Precision measurements- MW, Mtop, Bs Mixing, B states- MW and Mtop systematics statisics-limited

5. Can make a strong argument that pbar-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,

6. 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!)


A real CDF Top Quark A real CDF Top Quark EventEvent

Fit tFit t00 (start) from all tracks (start) from all tracks

W->charm sbar

W->electron+neutrino

B-quark

B-quark

T-quark->W+bquark

T-quark->W+bquark

Cal. EnergyFrom electron

T-Tbar -> W+bW-bbar

Can we follow the color flow through kaons, charm, bottom? TOF!

Measure transit time hereMeasure transit time here (stop)(stop)

TRIDENT

20

Peak Lum of 3E32Peak 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


The Learning Curve at a Hadron The Learning Curve at a Hadron Collider (Collider (LL))

Electron+

Electron-

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)

Take a systematics-dominated measurement: e.g. the W mass.


A real CDF Top Quark A real CDF Top Quark EventEvent

Fit tFit t00 (start) from all tracks (start) from all tracks

W->charm sbar

W->electron+neutrino

B-quark

B-quark

T-quark->W+bquark

T-quark->W+bquark

Cal. EnergyFrom electron

T-Tbar -> W+bW-bbar

Follow the color flow!

Measure transit time hereMeasure transit time here (stop)(stop)

TRIDENT


Luminosity vs TimeLuminosity vs Time

Note pattern- integral grows when you don’t stop, with increasing slope

Run II So FarRun II Run IIRun II

Xmas week

CDFD0

> 40 pb-1/wk/expt

Delivered Lum(CDF+D0)/2*

*(Protons are smaller on this side (joke))

Documents

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