# Presentation: 381533

## Studies on stand-alone Si tracking with SVT

- Alberto, Alessandro, _Pierluigi_

## Here we investigate the possibility to run SVT in the silicon only configuration.

- In a scenario with a bigger AM bank we could think about
- the possibility to store different pattern sets at the same time.
- Each pattern set is dedicated to different algorithm of pattern
- recognition.

- A pattern set for the usual silicon+XFT hits
- and
- _Silicon only patterns_

## What can we do with silicon only SVT?

- Increase  tracking acceptance in the forward regions   (||2) potentially useful for high Pt forward leptons...
- We would be able to select low Pt tracks below the XFT Pt treshold (2 - 1.5 GeV) in the central region.
- Other suggestions?!?

- Caveat: this is work in progress !!!

## Since we have L2 timing constraints (that are going to be more severe...) the first thing we have to do is try to understand if the corresponding workload for SVT is acceptable 

- In term of workload we intend to evaluate:
- The average number of Roads in output from the AM corresponding to the wedge with the maximum # Road per event.
- The total number of hit combinations faced by the track fitter in the wedge with maximum # Road per event.
- The average number of tracks in output from the TF considering the wedge with the max number of road per event.

- The wedge with max # roads-combinations drives the event timing!

- Feeling
- for the TF
- work load

## Slide 5

|  | PROS | CONS |
| --- | --- | --- |
| Road Warrior | Kills spurious 4/4 when 5/5 fires  | ? |
| Silicon only pattern restricted to the forward regions | Less patterns to be stored, potentially less random pattern firing | Not negligible overlapping with central region |
| Restricted Luminosity region in pattern generation | less pattern to store in the AM | Higher sensitivity to beam movements |
| Narrower Roads 
(I.e. SS size) | Less combinations inside a road | Road fake rate?
Less room for other algorithms  |
| Higher Pt threshold in pattern generation | Less patterns needed
 | Selective on physics |
| Majority logic 
(4/5  4/4,5/5) | More efficient | More patterns firing |
| Matching of tracks with other objects in the detector(forward leptons...) | Reduce the combinatorial
Possibility for new trigger selections for forward leptons | Efficient ? |

## SVTsim configuration: 

- Standalone silicon
- Enlarged pattern bank (71K  coverage 97%)
- Wider  coverage (-2,2)
- 4/5 majority logic
- Pt > 2 GeV/c
- 1.2 mm beam spot
- SS 12-8-8-8-12
- Track GB disabled
- Road busting

- We begin with the loosest configuration...

- Data from SVT test run 152133

## Pattern recognition workload

- Nroad fuori da AMS

- Nroad after ghost

- Ncomb

- Ntracks

## Lepton Matching

- Two possibilities:
-  L2 alpha matches SVT tracks to plug leptons
- SVT pattern recognition seeded by plug leptons
- Easiest starting point:
- Plug muons + SVT track
- Evaluate rejection
- If ok then test 2. on svtsim

## Forward Muon Triggers

- BMU * BSU(F)     1<<1.25
- BMU*BSU(R)*TSU  1.25<<1.5

- Studies based on run # 167715:
- L2_RL1.3HZ_L1_BMU10_BSUR_TSUO_&_CLC_v-1 (REAR)
- L2_RL0.7HZ_L1_BMU10_PT11_v-1                             (FRONT)

- TSU

- BSU

- BSU(R)

- BSU(F)

## Matching Performances

| Input Events | 625 |  |  |  |
| --- | --- | --- | --- | --- |
| Muon objects | 2389 | Pt>4 | Eta matching | Pt>4 and eta matching |
| SVT confirmed | 825 | 409 | 480 | 230 |
| Events selected | 248 | 165 | 184 | 115 |
| Avg. #of SVT tracks | 1.2 | 0.65 | 0.74 | 0.37 |
| Rejection | 39% | 26% | 29% | 18% |

| Input Events | 1159 |  |  |  |
| --- | --- | --- | --- | --- |
| Muon objects | 4510 | Pt>4 | Eta matching | Pt>4 and eta matching |
| SVT confirmed | 616 | 253 | 350 | 140 |
| Events selected | 237 | 131 | 166 | 85 |
| Avg. #of SVT tracks | 0.45 | 0.22 | 0.3 | 0.13 |
| Rejection | 20% | 11% | 14% | 7% |

- Front

- Rear

## What’s next

- Introduce muons in pattern recognition
- Understand matching efficiency
- Understand tracking resolution
- Further improvements:
- Stiffer Pt cut on muons
- Appropriate range in eta/Pt for patterns
- Narrower beam spot?