Diffraction and Color Coherence - Working Group VI

Working Group VI Chapter Write-up

Contributions to the Working Group VI Chapter are available here.

Schedule

• First General Meeting: Fermilab, March 4-6, 1999.
  • Plenary sessions
    • Al Mueller: Diffractive and Small-x Physics (20')
    • Andrew Brandt: D0 Run II Possibilities (10')
    • Mike Albrow: CDF Run II Possibilities (10')
  • Working Group VI Parallel Sessions (with links to transparencies and/or abstracts)
• Second General Meeting: Fermilab, June 3-4, 1999.
  • Working Group VI Parallel Sessions (with links to transparencies and/or abstracts)
• Third General Meeting: Fermilab Nov 4-6, 1999.
  • Working Group VI Parallel Sessions (with links to transparencies and/or abstracts)

Physics Agenda

Here is a list of physics topics (surely incomplete) to consider:

• Diffraction
  • Hard Diffraction (diffractive jet, W, Psi, top, etc. production)
  • Hard double pomeron (gap gap, gap track, track track) with jets, and other final states
  • Inclusive double pomeron (track track)
  • Glueballs/ Hadron spectroscopy in double pomeron
  • High-t elastic and diffractive scattering
  • Partonic structure of pomeron?
  • Parton-x dependence of gap fractions
  • Relationship to diffractive physics at HERA
  • Gaps as LHC tool?
• BFKL
  • Hard pomeron intercept and slope
  • Low ET very forward jets
  • Energy flow between forward jets
  • Low-x studies
  • Any good ideas?
• Color coherence
  • Can pursue in W+jet, Z+jet systems (statistics limited in Run I)
  • General hadron flow patterns
  • Difficult in jet systems. Any new ideas? (Kt algorithm?)
• Other topics, including:
  • Can we probe transition regions
  • 3 forward jets, other ideas from FELIX proposal
  • Gaps in rapidity along high-ET jet axes?
  • Diffractive production of SUSY?
  • minimum bias physics
  • New ideas requiring clever triggers
  • Monte Carlo generators

Specific Topics for Further Study

Topics discussed at the first meeting which require more work:

• Double Pomeron
  • MC predictions needed to predict rates for Run II
  • What states are allowed and disallowed?
  • What resonances to look for?
  • Summary of existing literature for references and predictions
  • What kind of mass resolution, particle ID do CDF & D0 have?
  • Can we identify glueballs? How to use partial wave analysis and related techniques?
  • Predictions of phi & t correlations of double pomeron (inclusive and hard)? Do these change for non-superhard pomeron?
  • Measure M(jj)/M(total) for existing data
  • Double pomeron to Higgs--Get more info on this
  • Centauros, DCC's in double pomeron. How to trigger? Any predictions?
• Diffractive structure functions
  • Inputting Hera functions into Tevatron.
  • Are HERA predictions stable?
  • Write up CDF beta method. Is this consistent with HERA? What about ESCALE error on jet ET's? Adding in reggeons?
• Other Diffraction
  • High t predictions for elastic and Single Diffraction at root_s=2000 GeV? Are there survival effects if high t?
  • Perturbative versus non-perturbative survival probability, following George Sterman's talk
  • Edge of gap predictions and existing measurements? How best to measure?
  • Photon-pomeron predictions? How to identify photon (Odderon?)? Is there input from HERA?
  • Gap fraction at HERA as f(xgamma)
• BFKL
  • Measure d2sig/dx1dx2 rather than ratio? (Don't worry about cancelling PDF's)
  • Use MC's to check exact D0 cuts, check PDF's
  • Forward jets in Run II? CDF studies on low ET forward jet possibilities?
• Monte Carlo Studies
  • Tuning PYTHIA+Pompyt.
  • New MC's?
  • Soft Color, Phojet studies?
  • Study effect of Underlying event on 0,1,2 gaps and ratios
• Other topics
  • What measurements can be made that are sensitive to impact parameter issues?
  • What measurements benefit from variable root_s?
  • Generalizing FELIX topics to Tevatron

Working Group List

Related Links

• FELIX home page
• QCD Working group for LHC Workshop
• Run II QCD and Weak Boson Workshop main page