90 likes | 184 Views
Status of the H(e,ep) Analysis. Chris Crawford Blast Analysis Mtg Dec 15, 2004. Dataset. 20 kC Dec 2003 p z =0.48 57 kC Apr 2004 p z =0.42 305 kC Dec 2004 p z =0.75. factor of 2.9 improvement in figure of merit. Kinematic Variable. over-determined. Kinematic Variable.
E N D
Status of theH(e,ep) Analysis Chris Crawford Blast Analysis Mtg Dec 15, 2004
Dataset • 20 kC Dec 2003 pz=0.48 • 57 kC Apr 2004 pz=0.42 • 305 kC Dec 2004 pz=0.75 factor of 2.9 improvement in figure of merit Blast Analysis Meeting
Kinematic Variable • over-determined Blast Analysis Meeting
Kinematic Variable • over-determined Blast Analysis Meeting
Kinematic Variable • over-determined Blast Analysis Meeting
Detector Asymmetry • need to correct for Q2L¹ Q2R • AL,R have strong Q2 dependence • systematic error of Q2 calibration discrepancy between L/R most important Blast Analysis Meeting
Q2 Calibration • kinematic fit elastic events c2 from WC (18 wires) + TOF timing incoporates mp as additional constraint • correct track parametersby comparison with kinematic fit • fit relative orientation of WC’susing parallax with cosmics • fit shift and rotation of WCby minimizing c2 above • BLAST field? Blast Analysis Meeting
Spin Angle dR/db¼ 0.0073/mp¢± • spin-angle measurement • global fit: b = 43.3±§ 2.5± • insensitive (both AL, AR same sign) • T20 fit: b = 46.5± - 2.5± + 3.5± • need more data at same angle • holding field map b¼ 45± • map field in complete volume (w/gradients) fit to either TOSCA or Harmonics • superposition of separate fields Blast Analysis Meeting
False Asymmetries • Beam • Target Blast Analysis Meeting