# Presentation: 551096

## The Level-2 Muon Trigger

-  Muon Level-2 Outline
-  Level-1 **/** Level-2 Muon-ID
-  Example Algorithm
-  Performance

**A. Maciel**
** ****(N.I.U.)**
**Muon-L2**

***ITEP -- LMU(Munich) -- Nevis Labs -- NIU***

***Arthur Maciel (N.I.U.)***
*For The D**Ø b-ID Vertical Review; FNAL 04-04-01*

## Muon Level-2 Outline

- Data processing happens in three stages;

- (1) _SLIC_’s   (track segment finding)

- (2)_ALPHA_  preprocessor  (track assembly)

- (3) _GLOBAL_  Level-2  (trigger decisions)

_**INPUT**_**	****	**_**PROCESSING**_**	****    **_**OUTPUT**_

**Muon Front**
**End Data**
- L1  Data

-    Pattern   Recognition
- Re-Format

- A - Layer Track Stubs
- BC-Layer Track Stubs
- L1-objects  (+Aphi)

******Compare all SLIC reported objects,  search for matches**
******Assemble matches (or singles) into final L2 muon candidates**
******Report track params. and ID-quality to L2(global) and L3(seeds)**

** ****Relate muon L2 candidates to other L2 objects, report triggers**

**A. Maciel**
** ****(N.I.U.)**
**Muon-L2**

***(C-code on T.I. DSP’s)***

***(C++ on Linux)***

***(C++ on Linux)***

## Overview of Muon L2 Algorithms

- Pre-Global muon ID is based on muon system only,  no cross referencing among different subdetectors  (L1 CFT Pt-thresh).
- Track segment finding for A and BC layers separately. Run1 Pt.
- Segments built from _both_ wire and scintillator elements.
- Calib: central wires have drift and φ(ΔT), Scints are T**0** subtracted.
- L2 reports single-cell-wide 3D tracks in (Pt,η,φ) coordinates.
- Central PDT (A)segments must satisfy track residual requirements.
- No vertexing, but hit patterns must be compatible with int. region.
- Added resolution (over L1) in track counting, pointing and timing.
- L2 candidate searches are not biased by or related to L1 results.

**A. Maciel**
** ****(N.I.U.)**
**Muon-L2**

## L2-Global Muon Candidates 

**Global L2 has two main functions; object **_**selection**_** and object **_**relations**_**  ****(objects: Jet,EM,MEt,MU,TRK,IP)**
**Muon **_**selection**_**; (Number, Pt, ************range****, Quality)**
**Muon **_**relations**_**;**
**Angular separation, Dimuon mass [CFT resolution]**
**Isolation,  muon inside jet,  track match **(Pt,η,φ) **, IP**
**Global can request object matches, but cannot do  track re-fits, or ID building beyond CFT****(Pt,****η,φ****)**
**Muon candidates sent to Global are also sent to L3 as seeds for data (detector module) unpacking**

**ALPHA**

**A. Maciel**
** ****(N.I.U.)**
**Muon-L2**

## Overview of the L2mu Software Project

**A. Maciel**
** ****(N.I.U.)**
**Muon-L2**

**SLIC Driver:**
** ****Init / Config / Test Suite**
** ****Soft & Hard Resets, SCL init.**
** ****Run control & monitoring**

**DSP-OS:**
** ****Boot Kernel (Init /Config /Test)**
** ****Data I/O ; driver and interrupts**
** ****Data I/O ; memory management**

**DSP-Alg:**
** ****Interface w/ mem. management**
** ****(A,BC)****x****(Central,Forward) , L1**
** ****Error handlers, Monitoring**

**DSP-5:**
** ****Event sort/build/format**
** ****Full readout events, M&P**
** ****Monitoring interface w/ VME**

**ALPHAS:**
** ****Worker ; Gen.Strategy,**
**              ****finalize formats**
** ****Administrator&Global**
**   ****(expecting a free ride)**

**Simulator:**
** ****Framework**
** ****Raw ******** L2 data**
** ****DSPs and Alpha**

**MC Studies:**
** ****Backgrounds**
** ****A-layer punch**
** ****Thin region punch**
** ****Halo and Multip.Int.**
**   ****(unmatched stubs)**
** ****Eff./Rej./Rates**
** ****L2 (Pt,****η,φ) resolution**

**1**

**2**

**3**

**4**

**5**

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***C & Asm***

***C ++***

## The Level-2 Muon Trigger

-  Muon Level-2 Outline
-  Level-1 **/** Level-2 Muon-ID
-  Example Algorithm
-  Performance

**A. Maciel**
** ****(N.I.U.)**
**Muon-L2**

***ITEP -- LMU(Munich) -- Nevis Labs -- NIU***

***Arthur Maciel (N.I.U.)***
*For The D**Ø b-ID Vertical Review; FNAL 04-04-01*

## L2 Muon ID

**CFT**
**φ wedge**

**octant ****wide**
**scint match**
**(η wedge)**

- MTC05

- MTC10

**PDT centroid**

**region ****wide**
**scint match**
**(φ wedge)**

- L2; SLIC+ALPHA

-  3D track resolution (counting)
-  A & BC segments separately
-       **A (3/4 hits)   BC (3/6 hits)**
-  A & BC crossing octants
-  High PT A-layer w/out BC
-  η dependence of hit patterns
-   **(pointing to interaction region)**
-  simultaneous look at 2 or 3
-     scintillator times on track

- SLICs receive calib**ed** data from Front Ends;
- PDT drift distances and phi (1st T-pair only)
- SCT  T**0**-subtracted times (w.r.to tile center)
- MDT hit addresses only, no drifts.
- 		and
- From L1;
**MTC05, MTC10, MTM, MCEN...**

- No cross referencing among
- different subdetectors before
- Global-L2
- (except L1 CFT-confirm & thres.)
- Run-1 muon P**T** (from toroid only)
- No (muon) Z-vertex point back

**A. Maciel**
**(NIU)**
**L2 muon**

- L1

## L2

-  Extra rejection can come from;
-  Tighter time gates
-  Event-wide inspection

***L2 is both an object-ID trigger ***_***and***_*** a physics trigger ***

|  Pt  | 4 GeV | (2,2)GeV | (2,4)GeV |
| --- | --- | --- | --- |
| η < 1 | 1 | 0.2 |  |
| η < 1.5 | 2 | 2 | 0.2 |
| η < 2 | 4 | 10 |  |

***~Expected L1 Muon Rates (KHz)***

***L1 muon bandwidth ~few KHz***

**5 MHz**

**10 KHz**

**1 KHz**

**20 Hz**

***L1***

***L2***

***L3***

- single
- track

***L2***

**>**
**~**

##     L2 Impact on L1 Muon-ID

-  Smallest granularity 3D tracking, improved wire-scint and L-L correl
-  More accurate object counting;   removes multiple triggers (stubs) resolves closely spaced tracks
-  Pt matching to L1 threshold
-  Narrower rejection time gate
-  Scint-TOF discrimination for Prompt - Slow - Out of Time
-  Recover crossing octant tracks
-  η dependence of hit patterns

**CFT**
**φ wedge**

- MTC05

**region ****wide**
**scint match**
**(φ wedge)**

**octant ****wide**
**scint match**
**(η wedge)**

- MTC10

**PDT centroid**

- L1 Muon ID

**calib**

**punch**

**pointing**

**A. Maciel**
** ****(N.I.U.)**
**Muon-L2**

**non-CFT fwd.**

**dimuons**

**MSP searches**

**(Pt,****η,φ****)**

## Comments for L3

-  “Muon-subdetector-only” ID largely done @L2
-                 Exploit other subdetectors !
-  Muon vertex - MTC vertex - min.H  vertex;  is the muon vertex  compatible with the rest of the event ? (multiple interactions)
-  Kinematics refitting,  dimuon masses, reln to other phys. objects
-  Back to back tracks - correlate scint times  (low Pt dimuons)
-  Number of hits on track (L2 fixed @6) - combinatorics(fwd)

**T**

**A. Maciel**
** ****(N.I.U.)**
**Muon-L2**

## The Level-2 Muon Trigger

-  Muon Level-2 Outline
-  Level-1 **/** Level-2 Muon-ID
-  Example  Algorithm
-  Performance

**A. Maciel**
** ****(N.I.U.)**
**Muon-L2**

***ITEP -- LMU(Munich) -- Nevis Labs -- NIU***

***Arthur Maciel (N.I.U.)***
*For The D**Ø b-ID Vertical Review; FNAL 04-04-01*

## SLIC Algorithms

**SLIC Algorithms**

- Ave. time budget = 25 μs

- Track stub finding (wire+scint)
- driven by lookup tables with:
-  valid wire hit patterns
-  wire geometry for track fit
-  valid wire-scint correlations

**PDT hit triplet**

**Scint. z-rows**

**beam**
**line**

**PDT**

**Central A Layer**

**A. Maciel**
** ****(N.I.U.)**
**Muon-L2**

**obs: wire-only or scint-only **
**stubs are not being considered**

-  Sweep octant in search for wire triplets
-  check that matching z-row has been hit
-  check triplet validity, calculate residual
-  assign scint time and phi, wire eta
-  report stub, continue octant sweep

-      A 3x4 Search
-          Window

## L2 Muon 3D Track Pointing

- Valid hit-triplet Patterns are listed on a lookup table

**Table has ****η dependence. One A-layer octant holds 40 valid patterns.  At each η, only up to 18max. are possibly valid.**

- Track receives a detector(η,φ)
- Track η is given by innermost cell
- Track φ is given by Aφ or Pixel
**PDT ΔT (triplet average) resolves doubles**

**L2 Muon 3D Track Pointing**

**sigma   = 0.09**
**LSB(****η****) = 0.05**

**A. Maciel**
** ****(N.I.U.)**
**Muon-L2**

## 	c  o  | d |   +   Offset    =  Res(dim L)    where...

- PDT  Hit  Triplet.   Wire Positions are;
-    ( **z** , **y** ) for cells  **i**n , **m**id , **o**ut
**       ****d** = Signed Drift Distances
-         Hit Position = ( **z+d** , **y** )

**d****in**

**d****mid**

**d****out**

**det    z****i**** + d****i****     z****m**** + d****m****      z****o**** + d****o****       =  0**
**              ****y****i****            y****m****             y****o**
**              ****1            1               1**

**The straight line segment constraint**

**determines a track stub residual equation for the drift times,**
**	****c****  ****o****  | d |   +   Offset    =  Res**(dim ***L***)    where...

- z

- y

**Requiring 3 cells hit   (out of max.=4)**

**A. Maciel**
** ****(N.I.U.)**
**Muon-L2**

## c  o  | d |   +   Offset    =  Res(dim L)

**c****  ****o****  | d |   +   Offset    =  Res**(dim ***L***)

**Offset  =        1          z****o****    z****m****    z****i**
**                   ****y****o**** – y****i****     y****o****    y****m****    y****i**
**                                   ****1       1       1**

**C****out**** ****=   *****sign  *****x     ****(y****m**** – y****i****) ****/**** (y****o**** – y****i****)**
**C****in****  ****=    *****sign *****x     ****(y****o**** – y****m****) ****/**** (y****o**** – y****i****)**
**C****mid**** ****=   *****sign *****x                   ****-**** ****1**

- Offsets are in  1      1
- correspondence with
-    Triplet “patterns”

- PDT  triggering must test residuals over all valid sign combinations

- Coefficients are in 1   1
- correspondence with
-    missing deck #

**A. Maciel**
** ****(N.I.U.)**
**Muon-L2**

## The Level-2 Muon Trigger

-  Muon Level-2 Outline
-  Level-1 **/** Level-2 Muon-ID
-  Example Algorithm
-  Performance

**A. Maciel**
** ****(N.I.U.)**
**Muon-L2**

***ITEP -- LMU(Munich) -- Nevis Labs -- NIU***

***Arthur Maciel (N.I.U.)***
*For The D**Ø b-ID Vertical Review; FNAL 04-04-01*

## DSP Evaluation

**μ****sec**

**window sweep**

**search one**

**search all**

- DSP Timing

**A. Maciel**
** ****(N.I.U.)**
**Muon-L2**

**DSP Evaluation**

-  Trigger code in assembly format
-  Download trigger code and tables
-  Each A layer DSP holds one octant
-  Code and tables are octant specific
-  Timing is for single track events
-  Backgnd: 5% random hits added
-  DSP internal memory has 64kB
-  Code and table have ~20kB each
-  DSP management code under study
-  SLIC: 4 worker DSPs, one manager
-  Central-A: 8 DSPs in parallel
-  Central-BC: 8 SLICs in parallel

## The L2 – Muon Object Finding

**The L2 – Muon Object Finding**

-          3x4 Search
-              Window

- A-layer PDT

- For each search window, find all valid hit triplets, deck ordered inside out.
- Each triplet is tested against trigger table for track segment and drift residual (here no scintillator match)

**A. Maciel**
** ****(N.I.U.)**
**Muon-L2**

## Slide 19

## .

- 1

- 8

-      *

- 3

- 2

- 5

- 6

- 7

- z

- y

- . . .
- 24 columns

- Four
-  decks

- 4

**   ****ROAD = + 009    - 011   - 013   +015**
**Triplet = +009 –013 +015  ;  Pattern = 0,0,1**

-    *

- *

- *

- *

**     ****ROAD = + 025    + 026   - 028  +030**
**Triplet = +017 +018 +022  ;  Pattern= -1,-1, 2**

- *

**Central A-****Layer**** PDT**

*Nb; patterns are triplet shapes, and*
*     **have  Z – translation invariance*

**A triplet “pattern”**
**is defined as two**
**cell projections,**
**and the missing**
**deck number**

- 1

**Barrel = 1 , 2 , 3**

**Cell  0**
**Coln 0**

**Col_in = 3**

- . . .

**95**

**89**

- 10

- 12

- 14

- 9

- 15

- 11

- 13

- 28

- 24

- 26

**column**

**A. Maciel**
** ****(N.I.U.)**
**Muon-L2**

**Notes:**
Nb; patterns are triplet shapes, and have translation(x) invariance

## Slide 21

## Slide 22

## Slide 23