1. Future Physics at HERMES
Random Thoughts on HERMES
No, I’m not speaking for 90 minutes…
A Little History
The Recoil Epoch (I.e., stolen slides)
Concluding Remarks (sermonette)
Ed Kinney
University of Colorado, Boulder, USA
1 July 2007
HEDT Symposium

2. The Recoil Detector Epoch
Physics Focus on Exclusive Reactions and GPDs
DVCS
1 July 2007
HEDT Symposium

3. First Observations of DVCS…
1 July 2007
HEDT Symposium

4. Factorization
1 July 2007
HEDT Symposium

5. Wigner Transforms (1932)
1 July 2007
HEDT Symposium

6. 3D Pictures of the Proton!!!
1 July 2007
HEDT Symposium

7. Measuring DVCS with true exclusivity
Recoil Detector
Measuring DVCS with true exclusivity
1 July 2007
HEDT Symposium

8. Recoil Detector Overview
1 Tesla Superconducting Solenoid
Photon Detector
3 layers of Tungsten/Scintillator
PID for higher momentum
detects Δ+pp0
Scintillating Fiber Detector
2 Barrels
2 Parallel- and 2 Stereo-Layers in each barrel
10° Stereo Angle
Momentum reconstruction & PID
Silicon Detector
16 double-sides sensors
10×10 cm2 active area each
2 layers
Inside HERA vacuum
momentum reconstruction & PID
HERA BEAM
Target Cell
1 July 2007
HEDT Symposium

9. HERMES Recoil Detector timeline
From 1996 through 2005 HERMES ran with the polarized H/D target.
November 2005 the ABS was removed.
In January 2006 the recoil detector was installed.
February started data taking.
Scintillating fiber detector worked immediately.
Silicon detector had serious beam induced noise.
Target and silicon damaged in May 2006.
Modified target installed July with repaired SI.
Timing problem with Photon detector also fixed in July.
Full detector operations since September 2006.
Timing on silicon final.
1 July 2007
HEDT Symposium

10. First experience with the Recoil Silicon Detector
Pedestal Stability
~1-2 channel shift expected caused by HERA.
Observed typically 4.
Surprise! 0.5% of the strips couple much stronger to the beam.
Pedestal correction due to beam current now implemented.
Fine tuning still necessary.
High-Low gain ratio OK.
Energy Calibration
Offline calibration seems not valid.
Use “punch-though” point as absolute gain.
Use MIP particle for a strip by strip relative calibration.
Crosstalk/clustering still under study
1 July 2007
HEDT Symposium

11. Recoil Detector Alignment
Six parameters (three translations and three rotations) which are common for all tracks are fitted
Each track is fitted with a straight line taking into account alignment parameters at current iteration
After iterative procedure converges it is repeated with new initial values of alignment parameters to be sure that alignment procedure does not depend on initial approach
Residuals and dependence of residuals on coordinates used as a tool to check alignment procedure
1 July 2007
HEDT Symposium

12. Residuals for the SFT from cosmic data
Parallel
top
=0.28mm
SFT
Parallel
Bottom
=0.31mm
1mm fibers
1 July 2007
HEDT Symposium

13. Data Tracking Full tracking is in production including alignment.
Efficiency of the tracking algorithm studied on MC and found to be 98.4 %.
Starting to study the efficiencies residuals and ghost tracks.
1 July 2007
HEDT Symposium

14. Running 7.4M DIS e- 2006 20M DIS e+ 2006 13M e+ 2007 maybe 20M in July
47M DIS for the unpol. Run
1M DIS ~24pb-1
~ 1 fb-1 proposed for our recoil detector running.
Not e+ e- balanced due to the initial startup problems.
10 M DIS on deuterium in addition.
1 July 2007
HEDT Symposium

15. Many Challenges ahead!!! Finish “Pre-Recoil” Analyses and publish!
Complete the analysis commissioning of the recoil
and release the first physics results!!
Publish, publish, publish!!!
Get your degree!!!
Publish, publish, publish!!!
Get your degree!!!
1 July 2007
HEDT Symposium

16. 1 July 2007
HEDT Symposium

17. 1 July 2007
HEDT Symposium

18. We must get the most from our data while the bells are still ringing!!!
1 July 2007
HEDT Symposium

19. To help you make great measurements!!!
Why am I here?
To help you make great measurements!!!
Take care of paperwork :(
Maintain Research Support
Keep the Collaboration Involved!
1 July 2007
HEDT Symposium

20. A HERMES Constant
Thanks to Sabine!!!
1 July 2007
HEDT Symposium

21. Critical Component of HERMES Success
1 July 2007
HEDT Symposium

22. The HERMES Research Trifecta
Working on exciting physics
Working with brilliant colleagues
Working with colleagues who became dear friends
Thanks to everyone for the experience of a lifetime!
1 July 2007
HEDT Symposium