yili's blog

trigger name	TOF3*VPDMB-5	TOF3*VPDMB-30
online vpd trigger	\|vpd vz\| < 5 cm	\|vpd vz\| < 30 cm
run number	16131050	16127045
trigger id	500607	59
Bandwidth	25 Hz	22 Hz
Prescale	2	1
trigger details	online.star.bnl.gov/RTS/production/triggerApp.php	online.star.bnl.gov/RTS/production/triggerApp.php

Plan: Compare vpd5 trigger vs vpd30 trigger with cuts on 5

For physics motiviation:
https://drupal.star.bnl.gov/STAR/system/files/HighMultiTrig_150313YL.pdf

For run15 pA 200GeV TOF3VPDMB30 vs VPDMB30 plots:
drupal.star.bnl.gov/STAR/blog/yili/run15-pau-200gev-tof3vpdmb-30-trigger

For run15 pp 200 GeV TOFMult3 QA plots:
drupal.star.bnl.gov/STAR/blog/yili/run15-pp-200gev-tof3vpd-trigger

For run12 pp 200 GeV MinBias and TOF high multiplicity QA plots:
https://drupal.star.bnl.gov/STAR/system/files/HighMultiTrig_150324YL.pdf

QA plot:

1. online trigger vpd information

Technique details:
TOF3VPDMB-30 uses VPD-TAC2 from online.star.bnl.gov/RTS/production/triggerApp.php
VPD-TACdiff2-max (1) is 4271, VPD-TACdiff2-min (1) is 4059
TOF3VPDMB-5 uses VPD-TAC from online.star.bnl.gov/RTS/production/triggerApp.php
VPD-TACdiff-max (1) is 4182, VPD-TACdiff-min (1) is 4147
In order to cut vpd vz to be 5 for TOF3VPDMB-30 data, we need to use [4147, 4182] as cuts.

Result:

The red line on the right plot is the cut will be applided to the result below. The cuts are the online vpd vz to be within 5 cm .

2. online TOFMult trigger

3. default Vz

Different!?

4. Vz with largest BTOFMatch value

There is one more Vz peak at 0 for vpd-5.

5. Number of primary tracks with default vertex

6. Number of primary tracks with vertex having largest BTOFMatch

Compare |Vz|<100 cm and Vz > 100 cm for the above two

Distribution shape difference?

7. Number of primary tracks Vs TOFmult for default vertex

8. Number of primary tracks Vs TOFmult for vertex with largest BTOFMatch

9. Number of primary tracks Vs vz for default vertex

10. Number of primary tracks Vs vz for default with largest BTOFMatch

Discussion:

1. vpd-5 for MB result can be found here from Xin Dong's study:
drupal.star.bnl.gov/STAR/blog/dongx/vpdmb-purity-check-and-vertex-position-check-pau-200-gev

The conclusion for MB vpd-5 is it does a pretty good job

2. vpd vz from btofheader:

3. loop over all vertices no matter vertex ranking
tpcVz vs vpdvz

(For the right plot, vpd-30, there is no 5-cm cuts.)

tpcVz vs online trigger vpd tac diff

(For the right plot, vpd-30, there is no 5-cm cuts.)

4. Use the tpc Vz closest to the online trigger vpd tac diff vz as vertex:

Vz distribution:

Number of primary tracks:

Number of primary tracks vs tofmult trigger: (vpdvz on the plot are the one from btofheader, not the online trigger one)

5. Self consistency check for trigger tofmult signal

The trigger TOFMult is read from MuEvent->triggerData()->tofMultiplicity();

This number can also be counted from trigger TOF Tray by
        for(int itry = 0; itry<120; itry ++) {          // 120 TOF tray
                UShort_t imult = muEvent->triggerData()->tofTrayMultiplicity(itry+1,0); // 0 for current bunch crossing
                if(imult<=24) mTOFMultcount+=imult;             // 24 is the maximum hits
        }

The TOF trigger mutliplicity from these two methods should be same and it has been checked:

6. VPDMB-30 Number of primary tracks vs TOFMult trigger for different vertices:

For default Vz, the majority show linear relationship, but there is also a line at small Number of Primary Tracks (close to x-axis) spreading towards large TOFMult trigger. After TOFMult > 75, the Number of Primary Tracks starts to saturate or run out of statistics.

For tpc vertex with the closest distance to online trigger vpd, it is wide relationship.

For vertex with the largest BTOFMatch, this one actually should not be relevant (it is not used in trigger for MB.)

7. TOF3*VPDMB-30 Number of primary tracks vs TOFMult trigger for different vertices:

Left: default vertex
Middle: tpc vertex closest to online trigger vpd vz
Right: vertex associated with largest BTOFMatch

For right one, largest BTOFMatch, compare |vpd|>200 and |vpd|>200 && |Vz|<100, the band of positive relationship between Number of Primary tracks and TOFMult (trigger) are all from |Vz|>100 cm (here is a Vz peak at 140 cm with most statistics for |Vz|>100 cm.)

Only |vpdvz (reconstructed in btofheader)|< 200 one shows TOFMult trigger selected higher Number of Primary Tracks.

8. TOF3*VPDMB-5 Number of primary tracks vs TOFMult trigger for different vertices: