Csc Cluster Reconstruction in new simulation (13.0.2) Woochun Park - PowerPoint PPT Presentation

Csc Cluster Reconstruction in new simulation (13.0.2) Woochun Park University of South Carolina @Muon Reconstruction Meeting September 20, 2007

Introduction • Gas gain in simulation is reduced from 1.0x10 5 to 0.58x10 5 . • Strip charges are reduced accordingly. • In cluster reconstruction, threshold algorithm is used. We need to make sure that all the parameters are reasonable for the new simulation.

Cluster Charge Distribution 12.0.6 simulation 13.0.20 simulation Q L +Q P +Q R

#Strips of Cluster Depending on Cluster Charge 12.0.6 thr=20k max=5 13.0.20 thr=20k max=5

Cluster Charge Distribution on #strips Black Line : 3 strips Blue Line : 4 strips Red Line : 5 strips 12.0.60 13.0.20 Q L +Q P +Q R • The more cluster charge distribution spreads, the more strips in cluster.

ClusterStatus Depending on Cluster Charge 12.0.6 thr=20k max=5 13.0.20 thr=20k max=5 Unspoiled Edge Multipeak Narrow Wide Skewed Inconst. % 0 2 3 4 5 6 11 12.0.6 85.6/0.7 1.8/0.1 0.1/0.0 1.0/0.1 7.9/0.2 1.0/0.1 2.6/0.1 13.0.20 82.2/0.6 1.5/0.1 0.4/0.0 4.7/0.1 5.9/0.2 1.2/0.1 4.1/0.1

Pull Width Dependence 13.0.20 Unpoiled + Spoiled Clusters Unpoiled Clusters Measured Strip Position eta

Residual on Cluster Charge max : max # strip in cluster 13.0.20 thr=20k max=5 12.0.6 thr=20k max=5 Cosmic result Clusters/(40 ADC counts) 300 0.05<|tan |<0.15 φ 250 200 0.30 Resolution (mm) 0.25 150 0.20 100 0.15 0.10 50 0.05 0 0 500 1000 1500 2000 2500 3000 3500 Cluster Charge (ADC counts) In cosmic data, spoiled clusters are included which make resolution worse at the high tail. Q L +Q P +Q R

Calculated Error vs. Cluster Charge 13.0.20 thr=20k max=5 12.0.6 thr=20k max=5 • Error is smaller than the residual. • Regardless of release, error estimates depending on cluster charges are similar. • This can be shown in pull width dependence on cluster charge in next page. • We may want to introduce additional error which is proportional to cluster charge.

Pull Width Dependence on Cluster Charge max : max # strip in cluster 13.0.20 thr=20k max=5 12.0.6 thr=20k max=5 Q L +Q P +Q R

Good efficiency on Cluster Charge max : max # strip in cluster 13.0.20 thr=20k max=5 12.0.6 thr=20k max=5 Q L +Q P +Q R Efficiency 1.000 � 0.999 Good effi 13.0.20 thr=20k max=5 0.986 ± 0.001 12.0.6 thr=20k max=5 0.995 ± 0.001

Good efficiency dependence on #strip and cluster charge 13.0.20 thr=20k max=5 Black Line : 3 strips Blue Line : 4 strips Red Line : 5 strips Q L +Q P +Q R • If cluster has 4 or 5 strips, more chance to be bad measurement.

Good Efficiency and #Strips • The cluster with more charges may suffer from delta electron nearby.

Bad Efficiency on Cluster Charge 13.0.20 thr=20k max=5 12.0.6 thr=20k max=5 Q L +Q P +Q R Mostly from 4 strips and 5 strips (previous page) Bad effi 13.0.20 thr=20k max=5 0.014 ± 0.001 12.0.6 thr=20k max=5 0.005 ± 0.001

Spoiled Fraction on Cluster Charge 13.0.20 thr=20k max=5 12.0.6 thr=20k max=5 Q L +Q P +Q R This behavior is understood in page 19. Spoiled Fraction 13.0.20 thr=20k max=5 0.184 ± 0.003 12.0.6 thr=20k max=5 0.144 ± 0.003

Eta Resultion • Position residual is correlated to strip charge amount. The more charges are deposited, the better resolution. Threshold is 20k e - . • • max # strips per cluster = 5 • Compared to 41microns in 12.0.6 simulation, the resolution becomes worse. 61.4 µ m

Eta Pull Distribution • Threshold is 20k e-. • max # strips per cluster = 5. • Compared to 1.004 in 12.0.6 simulation, pull width is comparable as 1.035.

ClusterStatus Depending on Cluster Charge 13.0.20 thr=20k max=5 • ClusterStatus – 0: Unspoiled The more cluster charge, the more failed – 2: Edge owing to too wide. – 3: Multipeak – 4: Narrow – 5: Wide – 6: Skewed – 11: Inconsist.

# Strips Depending on Cluster Charge 13.0.20 thr=20k max=5 Number of strips vs cluster charge. The more cluster charge, the more number strips Orange line indicates cluster has. the current cuts [3-5] for # strips of cluster.

# Strips Depending on Cluster Charge 12.0.6 thr=20k max=5 Number of strips vs cluster charge. The more cluster charge, the more number strips Orange line indicates cluster has. the current cuts [3-5] for # strips of cluster.

Conclusion & To do Gas gain is reduced to 0.58x10 5 from 1.0x10 5 in Csc simulation (13.0.20). • – Cluster charges are decreased accordingly. – Cluster position resolution is 61.4 microns (compared to 41 microns before). – Pull distribution width is not changed. – Temporarily, we suggest to keep using the previous parameters until we decide them. • No calibration is done yet. • Strip charge error (4300e) and angular error term (0.57mm) are unchanged. • Less Threshold is suggested but the previous one (20k) is okay. Bad cluster fraction is increased (0.5% � 1.4%) and spoiled fraction is increased • (14.4% � 18.4%) – Method to discriminate bad clusters (residual > 5 sigma) needs to be developed using extra information such as total charge, 4 th strip charge, skewness, number of strips, left-right inconsistency. – Cut needs to be decided on the plot of bad fraction vs. spoiled fraction. • Maximum # of strips. • Left-right significance. • Threshold • Cosmic data should be compared to the MC simulation – MuonCalibration is ready to subtract pedestal (Ketevi) and it’s available 13.0.30.