OD Calorimetry Study Update — Z vertex position dependence

OD Calorimetry Study Update— Z vertex position dependence Jaewon Park University of Rochester MINERvA/Jupiter Group Meeting, May 17, 2006

Contents • Calibration factor dependency • Beam energy • Theta • Phi • Radial primary vertex position • Longitudinal primary vertex position • We want that calibration factor doesn’t change too much

73.08cm 149.46cm 135.09cm 87.45cm OD-HCAL 212.85cm Active target Nuclear target DS-HCAL DS-ECAL DS-ECAL 243.9cm OD-HCAL Detector geometry andprimary vertex position • No ECAL, it’s just part of Active target • z=0 is set to center of whole detector volume automatically • z=0 depends on number of each module. • Active target is pretty much like cube • Should I consider center of Active target as most probably primary vertex ? • Probably center of upstream half of active target

Longitudinal primary vertex dependence • There’s some variation of resolution • Mean shift didn’t change much • Cut efficiency decreases as ID distance reduces

Comparison with radial offset • Resolution variation has similar pattern • Calibration factor and cut efficiency are very sensitive to radial primary vertex position

Looking at QE data - primary vertex position • In the QE configuration file, VERTEX 75. 0. 0. -119. 0 it means event will be generated randomly within a cylinder r=75cm, (x,y)=(0,0), -119<z<0 • Z distributes evenly • Larger radial distance has bigger contribution • Most of event will be best-or-worst resolution and calibration when particle goes to OD-HCAL

Looking at QE event data - theta distribution • Neugen events • Estimate how much proton will hit DS-HCAL • 40-50% • More accurate number can be obtained from direct simulation

OD Calorimetry Study Update — Z vertex position dependence