1. Electron-Proton-Collider Projects
HERA
eRHIC
March 29,2007
Electron-Proton Projects

2. (Wo)manpower Overview-status 3/07
H1 Scientists
Permanent Postdocs PhD Students
V. Chekelian J. Bracinik B. Antunovic
G. Grindhammer B. Olivier A. Dossanov
C. Kiesling A. Raspereza R. Kogler
A. Litpaj
A. Nikiforov
ZEUS I. Abt D. Kollar P. Devgun
A. Caldwell B. Reisert I. Jassal
W. Schmidke
March 29,2007
Electron-Proton Projects

3. Electron-Proton Projects
HERA
HERA II
e-P: ca. 290 pb-1 delivered
e+P: ca. 275 pb-1 delivered
HERA II Run ended March 22, 2007
Low energy running til July 2, 2007
March 29,2007
Electron-Proton Projects

4. Electron-Proton Projects
Jet Trigger
The jet trigger is an upgrade to the H1 first level trigger (large scale effort of MPI electronics department + physicists)
Jet finding at the first level
Reduced thresholds since use local sums
Operational since fall 2006
March 29,2007
Electron-Proton Projects

5. Electron-Proton Projects
Jet Trigger e
Jet Trigger
Level 1: 1 ms
CC analysis - improved efficiency for small angles !
Level 3: 150 ms
rate reduction x100 for low pT b-quarks and J/Psi
Low Proton Energy run:
Low energy electron trigger for y high NC
1 subtrigger
LAr Trigger
OR of 3 subtriggers
March 29,2007
Electron-Proton Projects

6. Electron-Proton Projects
HERA II Results
Neutral Currents at high Q2. Polarization allows extraction of au,vu,ad,vd
March 29,2007
Electron-Proton Projects

7. Electron-Proton Projects
HERA II Results
Charged Currents
Purely weak scattering - parity violation
See no Right-handed currents
March 29,2007
Electron-Proton Projects

8. Electron-Proton Projects
HERA II
The analysis of the HERA II data is producing results. Long list of expected analyses:
high Q2 and high x structure functions, polarization dependence
flavor dependent structure functions (F2c,b , u/d ratio, …)
EW parameters
heavy flavor production, fragmentation
jet production, jet properties, S, …
exotica
diffraction, exclusive processes, small-x physics
Focus on the low energy run currently in progress
March 29,2007
Electron-Proton Projects

9. Electron-Proton Projects
Proton Structure
Q2 dependence in agreement with the expectations of perturbative QCD (famous Dokshitzer, Gribov, Lipatov, Altarelli, Parisi evolution equations).
DGLAP
March 29,2007
Electron-Proton Projects

10. Electron-Proton Projects
Proton Structure
(small selection of data)
QCD based fits can follow the data accurately, yield parton densities.
DGLAP
March 29,2007
Electron-Proton Projects

11. Electron-Proton Projects
Proton Structure
BUT:
many free parameters (18-30) (DGLAP only knows how parton densities evolve in Q2)
form of parametrization fixed by hand (not given by theory)
Fits don’t agree at small-x ! In particular, large uncertainty in gluons
parametrizations should not be extended beyond measurement range in x
(divergence at fixed small-x larger at low Q2, smaller at high Q2)
March 29,2007
Electron-Proton Projects

12. Electron-Proton ProjectsFL
Need better data to test whether our parton densities are reasonable. The structure function FL will provide an important test.
negligible at small Q2
y2/Y+ r 1 F2
F2-FL
Need two beam energies to
measure FL
Ecm1
Ecm2
Directly sensitive to xg at small-x
March 29,2007
Electron-Proton Projects

13. Electron-Proton Projects
Low Energy Run
The HERA low energy has started and is planned to continue until 2 July, 2007 at 10:00AM. Expect 10 pb-1 of data.
March 29,2007
Electron-Proton Projects

14. Electron-Proton ProjectsFL H1
The FL measurement at HERA will serve primarily as a check of the gluon distributions extracted using the DGLAP fits
CTEQ5D R=0.25
MRST2002(LO)
MRST2004(NLO)
MRST2004(NNLO)
ZEUS
March 29,2007
Electron-Proton Projects

15. Electron-Proton Projects
Beyond HERA
SLAC-MIT,…
Rutherford
HERA
Understand small-x physics and hadronic structure is unfinished business. Ultimate goal is wavefunction of hadrons.
6-D structure - position & momentum distributions of partons, how spin is built up
nature of diffraction & high energy limit of interactions
March 29,2007
Electron-Proton Projects

16. Electron-Proton Projects
Beyond HERA
Ee=3-20 GeV Pe=80%
Ep= GeV Pp=70%
L=530 pb-1/week
EA= GeV/A PA=0%
L=580 pb-1/week/A
eRHIC
NSAC long range planning under way - priorities set this spring
Other ideas: forward physics at LHC, LHeC
March 29,2007
Electron-Proton Projects

17. Electron-Proton Projects
Beyond HERA
We have outlined a detector design for eRHIC based on our experience with the HERA physics - full acceptance detector.
hep-ex/
March 29,2007
Electron-Proton Projects

18. Electron-Proton Projects
Conclusions
HERA high luminosity running is over - run was successful, first results are coming out.
There are proposals under serious discussion for a future DIS program.
Low energy run has just started, and is expected to continue til the end of HERA (July 2, 2007)  FL.
March 29,2007
Electron-Proton Projects