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DIS from EMC to H1 T.Sloan, University of Lancaster. QCDN-06 Rome 2006

EMC proposal ’72-74 Build 1974-1978 Run 1978-1985 NMC (3 rd generation) SMC (4 th generation) Compass (5 th gen). H1 proposal 1985; Build 1985-1992 Run 1992 - 2007. DIS from EMC to H1 T.Sloan, University of Lancaster. QCDN-06 Rome 2006.

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DIS from EMC to H1 T.Sloan, University of Lancaster. QCDN-06 Rome 2006

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  1. EMC proposal ’72-74 Build 1974-1978 Run 1978-1985 NMC (3rd generation) SMC (4th generation) Compass (5th gen) H1 proposal 1985; Build 1985-1992 Run 1992 - 2007 DIS from EMC to H1T.Sloan, University of Lancaster.QCDN-06 Rome 2006 DIS discovered at SLAC in 1960s – 1990 Nobel Prize This led to - later generations of νN and μ(e)N experiments

  2. The Crowning Glory of the Work

  3. EMC Spin Effect.

  4. Proved that only a small fraction of nucleon’s spin is carried by the quarks. Incredible – we all thought we understood the quark-parton model. Is it ΔG or is the nucleon a Skyrmion ? Or is it something else ?

  5. Unexpected Effect (EMC Effect) NMC

  6. H1 How long will F2 Rise ?

  7. EMC BSM Observe J/ψ peak Charm cross section order of magnitude bigger Search for free quarks Search for D→μμ Set limit on BR D→μμ of < 3.4 10-4 (A. Staiano’s thesis - 1984) Sociology – one senior physicist commented on the draft paper Why have you done this analysis ? This is a very quiet paper.

  8. Was he correct ? There are 8 citations for the paper on Spires. • Look at quality of the citations • 1. Particle data group (paper still there) • 2. The experiment which copied us using a pion beam (bigger luminosity) • 3. Others If we had found a signal for D→μμ the standard model would have needed modification Conclusion We were right to do the analysis.

  9. The Collaborations • EMC and H1 Work divided into several sub groups • Structure Functions, Heavy flavour, hadronic final states (EMC and H1) • Diffraction, BSM (H1) – diffraction and the standard model not part of vocabulary in EMC days

  10. Heavy Flavour Physics • EMC discovered via multimuons that boson gluon fusion was responsible for charm production – among first evidence for gluons

  11. Contribution of b and c to F2 - F2cc and F2bb

  12. Hadronic Final States • Programme in EMC (NA2, NA9) • Lund Model developed for e+e- and μp data (ca1980). Much work was done to tune up the parameters of the model. • H1 works in Breit frame, studies jets etc. Jets give insight into production of primary quarks and gluons.

  13. EMC Inclusive Identified Hadrons - 1983

  14. EMC Seagull plot – gluon radiation (1983)

  15. H1 Scaling violations in fragmentation functions in Breit Frame compared to e+e- data.

  16. αs versus Q from event shapes

  17. Using dijets to constrain gluon distribution

  18. EW Physics First BCDMS measurementfrom μ+p μ-p differences BCDMS data

  19. H1 from e+p e-p differences

  20. Are there right handed currents ?

  21. Diffraction • Not known in EMC days except for exclusive ρ, φ, J/ψ … • Discovered in rapidity gap data at HERA. • Now also being studied in forward leading proton and neutron data. • Diffraction important for cosmic ray shower generation.

  22. Cosmic Ray shower simulation • Energy flow into forward region is very important for simulation of cosmic ray air showers. • Estimate ~x% of events have a leading proton and ~y% have a leading neutron. • Hence diffraction is important.

  23. ZEUS Leading neutrons Zeus Leading protons

  24. ISR leading photons ISR leading Neutrons (Flauger and Monnig

  25. Leading neutron data – ISR Is the bump at high x one pion exchange ?

  26. Holtmann,Szczurek,Speth Dashed ps meson exch Dotted vec meson exch Solid total

  27. Conclusions EMC and H1 have been great places to work. Plenty of outstanding questions – where is the spin of the proton ? What will limit the rise of F2 ? Is diffraction telling us something about the nuclear force ? Many questions for the workshop

  28. F2 Accuracy Now and 1996 Expected • Projected final accuracy is much better at x=0.65 than we actually have now. • Wider x range expected to be covered • (down to 1.4 10-5 compared to 6.510-5) • Improved systematic errors expected in 1996 compared to now. Eg 0.5% electron energy calibration backward and 1% central and forward (compared to 1% backward and 0.7%-3% central-forward). • Some work is needed here.

  29. PDF Accuracy 1996 Suggested to use jets to determine PDF by G.Lobo – fit made by ZEUS The ZEUS fit already approaches the accuracy expected in 1996.

  30. Measurement of xF3 from e+ e- differences Based on 16 pb-1 of e- data – so improvement expected.

  31. FL - 1996 Black points from extrapolation Measurement .Open from 4 proton Energies 10pb-1 at each

  32. Diffraction • In 1995/6 rapidity gaps had not been known for too long – so plans at workshop were primitive. • We have done much more than was considered at the workshop. • E.g.F2D3,F2D4, diffractive charm, vector meson production, dijets, DVCS…

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