GEM-CSC Trigger Taskforce Status Report

Jason Gilmore (Texas A&M University)

Sven Dildick (Rice University)

GE1/1 Workshop

11 June 2020

GEM-CSC Trigger Taskforce

• Group dedicated to the development, implementation, commissioning and deployment of the GEM-CSC trigger (and related algorithms) for Run-3– More than 60 different firmware, software or simulation tasks, further

organized into 9 “workgroups”

– Workgroups are arranged into four development phases based on completion sequence requirements

See next slide

• Documentation on the workgroups and the tasks is available on our twiki page– https://twiki.cern.ch/twiki/bin/view/CMS/GEMCSCTriggerTaskForceRun3

– “Deep details” are being added for each workgroup

– Suitable Monte Carlo samples (Run-3 campaigns)

– Software tools for trigger performance studies are being added as well

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GEM-CSC Trigger Development Phases

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WG3: Trigger data format

specifications

WG1: GEM trigger electronics

simulation and implementation

WG2: OTMB format

implementation

WG5: GEM-CSC timing and DAQ

at OTMB

WG4: GEM-EMTFInterface and

trigger

WG6: ILT and GEM trigger

algorithm implementation

WG7: GEM-CSC alignment interface

WG8: GEM OH link protocol

enhancement

WG9: High multiplicity

trigger

Phase 1Trigger primitive format

specifications

--V1 done; V2 in preparation

Phase 2Trigger primitive format

Implementation and validation

Phase 3Initial ILT and GEM

trigger implementationand validation

Phase 4Advanced ILT feature

implementation

A few snapshots from the twiki page

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Progress in WG3: Trigger data formats

• Baseline for studies: GEM and CSC trigger data format specifications for Run-3– Data formats have been formalized in detector note DN-20-016 (following

several expert discussions)

https://gitlab.cern.ch/tdr/notes/DN-20-016/blob/master/temp/DN-20-016_temp.pdf

• First version of the trigger data formats– MPC-to-EMTF trigger link based on existing 8b10b protocol

Can send 53 bits per chamber per BX to EMTF

2 x 25 bits/LCT + 3 timing/synchronization bits

Just enough space for CCLUT algorithm, GEM-CSC triggering and 2-3 bits for high-multiplicity triggering

No spare bits

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Progress in WG3: Trigger data formats

• Second version of trigger data formats– New MPC-to-EMTF protocol based on 38b40b encoding is being

tested and implemented

Would allow for more effective usage of available bandwidth

https://indico.cern.ch/event/921488/contributions/3871457/subcontributions/307424/attachments/2047050/3429994/MPC-EMTF-format-2020-05-28.pdf(Alex Madorksy & Mike Matveev)

Can send all 64 bits per BX for each chamber (32 bits per LCT)

Presents new opportunities for CSC trigger algorithm, GEM-CSC trigger data format and high-multiplicity triggering

New draft is being developed in this document

https://gitlab.cern.ch/tdr/notes/DN-20-016/-/blob/dev-38b40b/temp/DN-20-016_temp.pdf

• All trigger data formats have been defined in CMSSW– About a dozen PRs for GEM trigger pads, clusters, CSC CLCTs, ALCTs

and LCTs

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GEM and CSC trigger data formats note

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Progress in WG1: GEM Trigger simulation

• Yechan Kang (University of Seoul) is validating GEM trigger primitives in CMSSW

– Includes GEM trigger pads and trigger clusters

Occupancy plots in Monte Carlo look okay

Efficiency plots for pads look, clusters need to be understood further

– Relevant presentation:

https://indico.cern.ch/event/923161/contributions/3882837/attachments/2046766/3429450/28.May.GEMPadDigi.Yechan.pdf

• PR30169 and PR30115 to update GEM pads/cluster definitions and algorithms

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Pads

Clusters

Progress in WG2: OTMB format implementation

• Big task list in the GEM-CSC trigger taskforce, which focusses– Implement new data formats (CLCTs, LCTs, GEM-CSC ILTs)

Also extra fields for high-multiplicity triggering…

– Implement the CCLUT algorithm in simulation and firmware

– Transmission of LCTs in new data formats from (O)TMBs

– Handling of new data formats in MPC and EMTF

• High priority is the implementation & validation of the CCLUT algorithm

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Progress in WG2: CCLUT algorithm in simulation

• Implementation of CCLUT in CMSSW ongoing by Sven– https://indico.cern.ch/event/915204/contributions/3855665/attachments/20

33656/3404358/CSC_NewPatterns_SD_20200507.pdf

– New CSC trigger patterns:

–

– Several pull requests have been made to implement the patterns, enable parts of the algorithm and to define the new data formats

PRs: 28600, 28846, 29205, 29233, 29456, 29830, 30103 https://github.com/cms-data/L1Trigger-CSCTriggerPrimitives/pull/1

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Progress in WG2: CCLUT algorithm in simulation

• Missing piece is the actual CCLUT calculation. Being ported to CMSSW (PR30103)

• Next step is validation the algorithms:– Pattern and comparator code frequency

– Trigger efficiency

– Position bias and resolution

– Bending resolution (with & without GEMs)

• Instructions available on twiki page for Monte Carlo studies

• Results will be documented in the detector note– https://gitlab.cern.ch/tdr/notes/DN-19-059

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Open PRs for WG1/2/5

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Comparator Code Detector Note

• The comparator code look-up table (CCLUT) for CSC in Run-3 is being documented in a detector note DN-19-059

– Important so that work can proceed to implement the algorithm in firmware

– https://gitlab.cern.ch/tdr/notes/DN-19-059

• Contains an introduction, design and implementation considerations, and initial performance studies

• Note needs to be expanded with implementation into CMSSW and second set of performance studies using realistic TMB/OTMB simulation

– Plan to do this in the next couple of weeks/months

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Progress in WG2/WG6: CCLUT & GEM-CSC

• CCLUT and GEM-CSC trigger in OTMB firmware by Tao

– New logic blocks for the CCLUT and GEM-CSC trigger are being designed for the OTMBs and TMBs

– Part of CCLUT algorithm was implemented by Andrew Peck (UCLA). Tao is adapting his modifications for the production algorithm https://indico.cern.ch/event/915204/contributions/3855666/attachments/2033683/3405388/

TaoOTMBStatus_CMSGEMCSC_20200507.pdf

– TAMU emulation test-stand will be used to inject patterns and check performance of new algorithms

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WG6: GEM-CSC trigger implementation in simulation

• GEM-CSC trigger has been implemented in CMSSW since 2015

• Several rounds of development for Phase-2 TP, GEM TDR, Muon TDR

• Most recent studies done for Phase-2 L1-trigger TDR– https://indico.cern.ch/event/924135/contributions/3882826/attachm

ents/2048541/3434624/p2L1TUpgrade_TDR_V6_LHCC.pdf

• Tasks for next round of development on our twiki page– Focus on updating lookup-tables and data vs emulator comparisons

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Realistic timeline expectations for OTMB and related developments

1. GEM-EMTF trigger timing study– EMTF in b904 will time-in GEM trigger with trigger provided by CSC LCTs– Expected during July 2020 (+2 months)

2. OTMB CCLUT integration for improved CSC trigger– This will be tested at TAMU using our Emulator board system– Followed by cosmic ray testing at b904– Expected by August 2020 (+2 months)

3. OTMB new EMTF format implementation– This will be tested at b904 with EMTF in cosmic trigger studies– Expected by September 2020 (+2 months)– This includes OTMB DAQ data changes and CSC Unpacker software changes

4. Timing in GEM data at OTMB relative to common L1 trigger provided by EMTF– This will be tested in cosmic data runs at b904– This will be the first time we see GEM pad data in the OTMB DAQ path, our first real

OTMB integration test– This includes adding new timing tools in the OTMB online software– Expected by October 2020 (+2 months)– This assumes a full GE1/1 SC is attached near ME1/1 in b904 by 1 Sept 2020 (+2

months)16

5. Initial testing of OTMB GEM-CSC Integrated Local Trigger functionality– First trials of ILT will be tested at TAMU using our Emulator

board system– ILT tests with GEM and CSC chambers at b904 expected by

November 2020 (+2 months)

6. UXC plugging and commissioning for GE1/1 UXC fibers going to ME1/1 OTMBs– Assuming this will happen between August-November 2020 (+2

months)– OTMB has long-existing tools to monitor the link quality from

GEM OH links and verify they are reliable

7. UXC initial cosmic tests with GEM-CSC ILT trigger– Expecting that this will happen in December 2020 (+2 months)

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Realistic timeline expectations for OTMB and related developments

WG4: GEM-EMTF interface

• Several presentations in GEM-CSC meetings

– A few relevant links included in next slides

• May 12, discussion with EMTF experts

– Connections between CSC and EMTF at b904 need to be installed and tested, and the CSC run control system at b904 has to be modified to take cosmic data runs with EMTF rather than the old CSC TF.

– CSC will try to arrange capability and permissions to get this configured to run remotely with HV on at b904.This is under investigation

– Single miniDAQ which includes DAQ for GEM, CSC and EMTFAll relevant RAW data from a local run in single ROOT files

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Progress in WG4/WG8: GEM-EMTF link testing

• Implementation and testing in firmware by Evaldas Juska et al.– https://indico.cern.ch/event/915204/contributions/3855664/attachm

ents/2034056/3405111/2020-05-07_EJ_trig.pdf

– Also includes upgrade of bandwidth 3.2 Gb/s to 4 Gb/s on OH-to-CTP7 trigger link

– Links are implemented and have been proven to be reliable at B904

– Next steps include extensive testing at B904 with CSC chamber, GEM superchamber, HV/LV, gas, EMTF trigger, working CSC/GEM/EMTF DAQ+unpackers

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Progress in WG4: EMTF firmware & emulator

• Recent presentation by Efe Yigitbasi (UF) on the status of the GEM-EMTF project– Work is ongoing in firmware and the software emulator

– Implemented option for Local L1 trigger on “any GEM cluster”

https://indico.cern.ch/event/911354/contributions/3837165/attachments/2025714/3388682/EMTF_GEMIntegration_GEMCSCMeeting_23.04.2020.pdf

– New postdoc at UF will be investigating options to include GEM trigger data for the Run-3 EMTF algorithm in simulation for prompt muons

– Displaced muons: DNN developed for Phase-2 is being adapted for Run-3

https://indico.cern.ch/event/923161/contributions/3882104/attachments/2046338/3428584/EMTF_GEM_plans.pdf

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WG4: EMTF BDT Training for Run-3

• BDT-based pT assignment in EMTF was used during Run-2

• Options to include GEM-CSC bending angle in EMTF under study with Run-3 MC samples– Matthew Decaro (Rice University)

• Results to be document in detector note– https://gitlab.cern.ch/tdr/notes/DN-20-024

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WG7: GEM-CSC trigger alignment interface

• Recent presentation by Hyunyong Kim

– https://indico.cern.ch/event/876047/contributions/3858436/attachments/2036238/3409373/HyunyongKimTBMuAl0511.pdf

• Alignment is not included in the GEM-CSC trigger

– Also not included in the GEM-EMTF trigger

• Precise alignment is needed to properly calculate the GEM-CSC bending angle

• Preliminary plan is to use existing alignment framework in CMSSW to modify lookup-tables for GEM-CLCT matching

– Need about ~2 fb-1 of pp collision data (~15k muons/chamber)

Obtain very crude alignment with cosmic data during 2021-2022, before precision alignment with first Run-3 pp runs

– We need to initiate discussions how we will adapt the GEM-CSC trigger in CMSSW and in firmware/online software

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WG9: High-multiplicity triggering

• Covers investigation of exotic signatures that CSC & GEM-CSC triggers may be sensitive to during Run-3

• Current studies

– Tau -> 3 mu studies by Simone Calzaferri (INFN Bari)

– Hadronic showers in muon system by Nik Menendez (UF) et al.)

• Tau -> 3 mu: Studying the performance of different trigger algorithms which rely on the proximity (dR) and the GEM-CSC bending angle of stubs in the endcap

So far only ME1/1 is being considered. Plan to expand the study to all CSC stations

– Initial study on rates with different trigger/threshold proposals

Few prototype trigger seeds for Run-3, which need to be further fleshed out

https://indico.cern.ch/event/923161/contributions/3882106/attachments/2046675/3429299/20200521_Tau3MuStatus.pdf

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WG9: High-multiplicity triggering

• Hadronic showers in the muon system from decays of long-lived particles– H -> 2a -> 4b: one of several physics channels that is being considered

for the high multiplicity bits in each chamber

– Trigger rates and in each sector are being calculated using Monte Carlo minimum bias samples

– Trigger efficiencies are being evaluated for different displacements and “a” boson masses

https://indico.cern.ch/event/907528/contributions/3821995/attachments/2018254/3373660/LLP_Trigger.pdf

Showcase @LLP2020: https://indico.cern.ch/event/863077/contributions/3850860/attachments/2045232/3427570/LLPWorkshop_20200523_SD.pdf

– Results being documented in detector note

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Taskforce Plans June-July

• Plan to have our regular biweekly meetings

• Expected topics of discussion– GEM-EMTF trigger status and plans for Run-3

– Results on the CCLUT algorithm in simulation (by Mid-July)

– Continued investigation of high-multiplicity studies + expand to other signatures

– First discussions on alignment interface for GEM-CSC trigger and GEM-EMTF trigger

– Preliminary results on using the GEM-CSC bending angle in EMTF

– Start up discussions on GEM trigger data in CSC DQM and EMTF DQM

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Backups

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Tasks on the GEM-CSC Trigger Taskforce twiki

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• All tasks considered by the task force are listed on the twikipage, and are grouped into 8 work groups.

• WG1 and WG2 listed below as example

GEM-CSC Trigger Development-Phase Definitions• Development Phase Names and Work Group assignments

– Trigger Primitive Format specifications Definitions for protocols between systems

WG3: “Trigger data format specifications”

– Trigger Primitive Format Implementation and Validation This includes firmware and simulation challenges for any system impacted by the

format change

WG1,2,5,4: “GEM trigger electronics simulation and implementation”

“OTMB format implementation”

“GEM-CSC timing and DAQ at OTMB”

“GEM-EMTF Interface and Trigger”

– Initial ILT and GEM trigger implementation and Validation Includes firmware and simulation challenges for OTMB, old TMB, MPC, EMTF, GEM

WG6: ”ILT and GEM trigger algorithm implementation”

– Advanced ILT feature implementation This includes firmware and simulation challenges for GEM and CSC

WG7,8,9: “GEM-CSC alignment interface”

“GEM OH link protocol enhancement”

“High multiplicity trigger”28