Difference: EfficiencyStudies (1 vs. 2)

Revision 22014-03-07 - ZhenHu

Line: 1 to 1
 
META TOPICPARENT name="L1TrackingTrigger"

Efficiency Studies

Changed:
<
<
Efficiency drop at |eta|=1.05

We see the PR efficiency drops to 50% at around |eta| = 1.05. We want to figure out the reason of this inefficiency.






Eta definition



Even in a tiny eta region, the fired stubs are spreaded in a wide band.

In eta region (-1.06, -1.04) :



This is because the tracks are genereated with a flat Gen_z0 distribution between -15cm and 15cm. So for each given Gen_eta value, the tracks will be found in a (-15,15) band.

Gen_z0:


Stub_eta = Gen_eta







Fake layer

in CMSPatternLayer.cc, we use Gen_eta to decide whether a fake layer will be assigned to the pattern.

225 map<int, pair<float,float> > CMSPatternLayer::getLayerDefInEta(){
226 map<int,pair<float,float> > eta;

//barrel
227 eta[5]=pair<float,float>(-2.2,2.2);
228 eta[6]=pair<float,float>(-1.72,1.72);
229 eta[7]=pair<float,float>(-1.4,1.4);
230 eta[8]=pair<float,float>(-1.2,1.2);
231 eta[9]=pair<float,float>(-1.1,1.1); layer 9 (-1.0,1.0)
232 eta[10]=pair<float,float>(-0.9,0.9);
//endcap
233 eta[11]=pair<float,float>(1.1,2.4);
234 eta[12]=pair<float,float>(1.2,2.4);
235 eta[13]=pair<float,float>(1.3,2.4);
236 eta[14]=pair<float,float>(1.4,2.5);
237 eta[15]=pair<float,float>(1.6,2.5);
//endcap
238 eta[18]=pair<float,float>(-2.4,-1.1);
239 eta[19]=pair<float,float>(-2.4,-1.2);
240 eta[20]=pair<float,float>(-2.4,-1.3);
241 eta[21]=pair<float,float>(-2.5,-1.4);
242 eta[22]=pair<float,float>(-2.5,-1.6);

243 return eta;
>
>
Efficiency drop at |eta|=1.05

We see the PR efficiency drops to 50% at around |eta| = 1.05. We want to figure out the reason of this inefficiency.






Eta definition



Even in a tiny eta region, the fired stubs are spreaded in a wide band.

In eta region (-1.06, -1.04) :



This is because the tracks are genereated with a flat Gen_z0 distribution between -15cm and 15cm. So for each given Gen_eta value, the tracks will be found in a (-15,15) band.

Gen_z0:


Stub_eta is not equal to Gen_eta







Fake layer

in CMSPatternLayer.cc, we use Gen_eta to decide whether a fake layer will be assigned to the pattern.

225 map<int, pair<float,float> > CMSPatternLayer::getLayerDefInEta(){
226 map<int,pair<float,float> > eta;

//barrel
227 eta[5]=pair<float,float>(-2.2,2.2);
228 eta[6]=pair<float,float>(-1.72,1.72);
229 eta[7]=pair<float,float>(-1.4,1.4);
230 eta[8]=pair<float,float>(-1.2,1.2);
231 eta[9]=pair<float,float>(-1.1,1.1); layer 9 (-1.0,1.0)
232 eta[10]=pair<float,float>(-0.9,0.9);
//endcap
233 eta[11]=pair<float,float>(1.1,2.4);
234 eta[12]=pair<float,float>(1.2,2.4);
235 eta[13]=pair<float,float>(1.3,2.4);
236 eta[14]=pair<float,float>(1.4,2.5);
237 eta[15]=pair<float,float>(1.6,2.5);
//endcap
238 eta[18]=pair<float,float>(-2.4,-1.1);
239 eta[19]=pair<float,float>(-2.4,-1.2);
240 eta[20]=pair<float,float>(-2.4,-1.3);
241 eta[21]=pair<float,float>(-2.5,-1.4);
242 eta[22]=pair<float,float>(-2.5,-1.6);

243 return eta;