The Level 2 Section of Trigger_Examine


The Users' L2 Examine

Level 2 histograms are available by running the trigger_examine process. This process runs as an examine from the data distributor. It produces a rootuple from the d0_analyze process, then a second process generates a series of histograms from the roottuple output.

The plots are organized into inputs to the Level 2 workers, and those that passed the Level 2 global processor (outputs). Every event in the output plots have passed a Level 2 trigger, but there is no information in the Examine as to which trigger was passed. The input plots have events that have passed a Level 1 trigger, but the events might have passed any Level 1 trigger, or multiple triggers.

The following pages of plots are available from the trigger gmbrowser:

Please check that histograms match the red reference histograms.

GM Page				Histogram		Description
---------------			----------------	----------------------------------------------
L2 output Jets			number per event	jets in all events that passed L2
				Pt			thresholds at 5 and 20 GeV (set by trigger list)
				eta			~symmetrical about 0, dips at ICR (1.1-1.2)
				phi			~flat
				eta vs. phi		white boxes for masked hot cells, bands for ICR		
							  - no ref. plot, so compare to previous plots	

L2 output EM Objects 1 		number per event	electrons in all events that passed L2
				Pt			exponenential decay, thresholds at 5 and 10 GeV
				eta			~symmetrical about 0, dips at ICR (1.1-1.2)
				phi			~flat
				eta vs. phi		white boxes for masked hot cells, bands for ICR
							  - no ref. plot, so compare to previous plots	

L2 output EM Objects 2		isolation		electron isolation
				EM fraction		EM fraction cut above 0.8

L2 output Muons			number per event	muons in all events that passed L2
				Pt			thresholds at 2 and 5 GeV
				eta			~symmetrical about 0, dip at zero
				phi			~9 spikes (Phi information sometimes gets 
							   lumped to the center of a pad.  Central and
							   Forward don't line up exactly.  So, ~9 spikes.)
				eta vs. phi		darker phi bands for the phi spikes
							  - no ref. plot, so compare to previous plots	
				quality			1 for loose, 2 for medium, 3 for tight muons
							  (no muons are double-counted)

L2 input elec 1			number per event	electrons in all events that passed Level 1
	       			Et			thresholds set by L1 trigger list
				eta			~symmetrical about 0, dips at ICR (1.1-1.2)
				phi			~flat

L2 input elec 2			eta vs. phi		white boxes for masked hot cells, bands for ICR
							  - no ref. plot, so compare to previous plots	
				EM fraction		EM fraction, btw. 0 and 1
				isolation		electron isolation

L2 input jets 			number per event	jets in all events that passed L1
				Et			thresholds set by L1 trigger list
				eta			~symmetrical about 0, dips at ICR (1.1-1.2)
				phi			~flat
				eta vs. phi		white boxes for masked hot cells, bands for ICR	
							  - no ref. plot, so compare to previous plots	

L2 input central muons		number per event	central muons in all events that passed L1 
				pt			the pt measurement of the central muons (spike at 0)
								(negative pt's for negatively charged muons)
				eta			~symmetrical about 0, dip at zero 
				phi			~6 spikes (Phi information sometimes gets 
							   lumped to the center of a pad.) 
				eta vs. phi		darker phi bands for the phi spikes	
							  - no ref. plot, so compare to previous plots	

L2 input forward muons		number per event	forward muons in all events that passed L1 
				pt			the pt measurement of the forward muons (spike at 0)
								(negative pt's for negatively charged muons)
				eta			~symmetrical about 0, dip at zero
				phi			~6 spikes (Phi information sometimes gets 
							   lumped to the center of a pad.) 
				eta vs. phi		darker phi bands for the phi spikes	
							  - no ref. plot, so compare to previous plots	



There is another version of the Examine, which was designed for use by Level 2 experts, primarily for system debugging and commissioning. The Expert Examine shows slightly more details in its plots, and it has the ability to select plots that correspond to a particular trigger bit.


Send comments/corrections to Joe Steele
Last modified: Tues. April 29, 2003