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Future Physics at HERMES. No, I’m not speaking for 90 minutes…. Random Thoughts on HERMES. A Little History The Recoil Epoch (I.e., stolen slides) Concluding Remarks (sermonette). Ed Kinney. University of Colorado, Boulder, USA. The Recoil Detector Epoch.
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Future Physics at HERMES No, I’m not speaking for 90 minutes… Random Thoughts on HERMES • A Little History • The Recoil Epoch (I.e., stolen slides) • Concluding Remarks (sermonette) Ed Kinney University of Colorado, Boulder, USA HEDT Symposium
The Recoil Detector Epoch • Physics Focus on Exclusive Reactions and GPDs DVCS HEDT Symposium
First Observations of DVCS… HEDT Symposium
Factorization HEDT Symposium
Wigner Transforms (1932) HEDT Symposium
3D Pictures of the Proton!!! HEDT Symposium
Recoil Detector Measuring DVCS with true exclusivity HEDT Symposium
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 HERA BEAM Silicon Detector • 16 double-sides sensors • 10×10 cm2 active area each • 2 layers • Inside HERA vacuum • momentum reconstruction & PID Target Cell HEDT Symposium
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. HEDT Symposium
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 HEDT Symposium
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 HEDT Symposium
Residuals for the SFT from cosmic data SFT Parallel top =0.28mm SFT Parallel Bottom =0.31mm 1mm fibers HEDT Symposium
Tracking Data • 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. HEDT Symposium
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. HEDT Symposium
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!!! HEDT Symposium
We must get the most from our data while the bells are still ringing!!! HEDT Symposium
Take care of paperwork :( Maintain Research Support Keep the Collaboration Involved! Why am I here? • To help you make great measurements!!! HEDT Symposium
A HERMES Constant Thanks to Sabine!!! HEDT Symposium
Critical Component of HERMES Success HEDT Symposium
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! HEDT Symposium