γ+ d → p + p + π- Analysis Status
Y.C.Han@NKS2 Meeting
Dec20, 2007
Outline
• Debug in source and macro file
• Check analysis method w/ simulation
• Analysis of Jan2007’s experiment data
Debug
• In source file P3TrVertex3D.cpp1. debug three tracks’ rotation angle;
2. return track’s momentum w/ mean values in two
2TrVertex reconstruction • In root macro files Correct the mixing use of three tracks’ momentum
• Simulation Some changes of Generator
upgrade the formater
Check analysis method w/ simulation
1. Check simulation’s 3BPS generator uniform or not
2. Compare simulation data before and after analysis by check the geometrics and kinematics
center of mass frame
L1: p1
L2: p2
L3: π-
( MeV )
Uniform??
The theta distibution don’t show uniform ?
laboratory frame
L1: p1
L2: p2
L3: π-
( MeV )
The method needs improve on Z Axis
How to understand the two peaks tendency ?
Peak less than PDG Mass ~24MeV
Analysis of Jan2007 exp data
• The data is under analyzed. There are about 70% data finished until this morning. The following are some of the preliminary check for these part data.
w/o cut
LVp1(MomP1, Ep1);
LVp2(MomP2, Ep2);
LVpi (MomPi, Epi);
LVg(Momg, Eg);
LVTar=LVp1+LVp2+LVpi-LVg;
W/ PDG mass
w/ reconstruct target mass cut
Simulation
Simulation
w/ reconstruct target mass cut
The difference from simulation is from ground, fluctuation due to small events #,
or simple simulation ?
w/ reconstruct target mass cut
c.f. LVmiss W/O cut
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