General Meeting Summary 4/9/15

PWO CRYSTAL TESTS - TRANSMITTANCE

Spring 2014: crystal #1-10 (results below are from measurements performed after the Idaho irradiation tests)
December 2014: crystal #11-15 (had not been measured before)

Crystal #14 has strange behavior above ~500 nm; this observation does not seem to be a feature of the experimental setup
Crystal #12 also shows differences in transmittance from the other crystals when looking specifically at wave lengths 370 nm and to some extent 420 and 500 nm
Note that crystal #9 longitudinal transmittance is consistent with the other crystals. This is different from what is observed for the transverse transmittance

General result from this transmittance test: ~20% of the entire set of crystals does not meet specifications

Additional observations regarding and tests with the crystals returned from the Idaho irradiation tests (#1-10)

Some of the crystals seem to retain a brownish color, in particular crystal #2 (this is one of the crystals being sent to Rainer)
Test of curing system - difficult to reach a conclusion
ACTION ITEM: make a table of all crystals with transmittance results at specific wavelengths, e.g., 370 nm, 420 nm, and 500 nm

TCS WITH NPS LOI

Uses NH3 target, two NPS type detectors to detect the lepton pair, and a combination of tracker (~3mm scintillating fiber) and hodoscope to detector the recoil protons

Initial simulations have been carried out and geometry of experimental setup has been determined. Note that the detector configuration in Hall C is flexible and can be optimized, i.e., detector placement

Acceptance: studies ongoing to estimate the effect of target high field on proton deflection - implementation of magnetic field maps in the simulation. Initial studies show that angle is on order 1-2 degrees and so protons will make it out of the target
Reconstruction of the recoil proton - impacts resolution. Ongoing studies to parameterize the acceptance to estimate the impact on the data.

Based on VGG model; modifications include options for electron or real photon
Initial results show a ~20% transverse target spin asymmetries
Fits for physics case have been started. To estimate the impact of the data on these fits need: 1) error bars, 2) luminosity per day, 3) target length, 4) acceptance for the desired binning (limited theta for a given phi angle may have an impact on the projected asymmetry)
uncertainty sources include statistics and bin width. Suggested bin width in t is less than 0.2 GeV/c^2 since the cross section depends strongly on t

ITEMS FOR NEXT MEETING:

NEXT MEETING: THUR., 30 APRIL 9:00 AM (EST)

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