Silicon/Trigger party: ~ 60 showed up May 6th @ Ted’s place
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Silicon/Trigger party: ~ 60 showed upMay 6th @ Ted’s place
Default table
Old High-lumi
May 6th was also Larry’s B-day… and Vadim, Florencia, Ricardo…Q without A: what’s going on 9 months before May 6th?
Professor Dee’s speech on how to improve bandwidth for babies …
Trigger Issues at higher luminosity
Ted Liu
Fermilab
CDF Elba
June 03, 2006
Why higher luminosity?-- A story I learned in graduate school …
Long ago, a famous young HEP theoretical physicist kept having trouble finding a girl-friend for a long time …
He then complained about it to Hans Bethe
Hans’s advice:
“Young man, if the cross section is so low, increase the luminosity !”
For HEP experimental physicists,
this is easier said than done
Not only the luminosity has to be increased, but also the bandwidth …
from collision point all the way to PRL editors office … Trigger is just part of this process
PRL
Improving bandwidth
detector OnlineTrigger/DAQ
Offline computing
Analysis/meetings
~100s ns ~ µs to ~ms ~weeks ~ months … beam time and life time …
What is trigger business ?-- the more you learn, the less you know
Many aspects of trigger business Is it about improving trigger bandwidth? Yes and No Is it about improving signal purity? Yes and No Is it about having more signal events on tape? Yes and No Is it about reducing deadtime? Yes and No Is it …?
To some extend, it is about dealing with our ignorance as we don’t know exactly how the background (or even signals) will look like …
detector OnlineTrigger/DAQ
Offline computing
Analysis/meetings
PRL
~100s ns ~ µs to ~ms ~weeks ~ months
Trigger Table
Trigger Table: a trigger “menu” to configure the trigger system to Select a list of physics triggers determined by L1/L2/L3 requirements determines the physics we can do (hadron collider physics ~ trigger table)
In principle, a physics process trigger cross section, = B (constant) In reality, a given trigger cross section, ~ A/L + B + CL + DL2
CDF trigger table contains > ~ 50 L1 triggers, > ~100 L2 & L3 triggers… Solution - relax the effective prescale in real time as luminosity falls
High Pt physics triggers less likely get prescaled
PRLdetector
OnlineTrigger/DAQ
Offline computing Analysis/meetings
~100s ns ~ µs to ~ms ~weeks ~ months
+ …
Trigger Table performance in the old days (July 04)
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@ ~90E30, deadtime > 20%
with L1A ~ 28KHz
Because of high deadtime, at luminosity above 90E30, we had to run with a special trigger table with a smaller set of triggers:
the so called “high lumi table” … Rate back-pressured due to deadtime
Taken July, 2004
Trigger Table performance this year
-- Table 3_09 (1st GUT), designed for 170E30
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QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.* Significant trigger table performance optimization/improvements in the past year* Take advantage of: L2/SVT/EVB/L3 upgrade improvements
@ deadtime average over typical store: ~ 5%
High luminosity store 4590Taken Jan. 13, 2006
Dynamically enable high rate B triggersas luminosity falls (more bandwidthavailable at lower luminosity).
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When the table is pushed to its limit… >170E30
Feb. 12th, 2006Table 4_00Initial lumi: 176E30
At Initial lumi: ~176E30L2A: ~ 630Hz High deadtime > 20%L1A back-pressured
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Busy deadtime wall
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rather sharphard wall
we will be a L2A limited experimentfor long time to come …EVB upgrade helped us A LOT,still some room for improvement, but there is a limit (~< 1KHz). At higher luminosity, the available bandwidth could be smaller…the real problem is that L2A x-section grows too fast for many triggers …
~630Hz
L3A & data rate
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What are those L2 triggers with fast growth term?
A few stand out, have highest rate at 176E30 But there are MANY grow up very fast Some of them are backup triggers, with high growth
term by its very nature… they may look small now… but they will grow quickly at higher luminosity…
This is the MAIN challenge at higher luminosity… for RunIIb table
L2 triggers with high growth term
-- roughly in three categories
.Track/mu related:
e.g. CMX etc
L2CAL related:
e.g. MET+2JETsbackups
What can we do?
May 12th Trigger Workshop
Bring physics group and trigger folks together To prepare for higher luminosity running We have done great in the past, but we have major
challenges ahead of us!
PRL
Improving bandwidth & physics sensitivity
detector OnlineTrigger/DAQ
Offline computing
Analysis/meetings
~100s ns ~ µs to ~ms ~weeks ~ months … beam time and life time …
Physics Triggers vs hardware improvements
-- initial discussions with Beate & others
Official RunIIb triggers RunIIb waiting list Backup triggers
New trigger ideas * w/ existing system * w/ new hardware improvements * optimizing in mid/low lumi
Sensitivity vs Inst. Luminosity
* background (trigger growth term) * purity * detector performance * systematics …. etc
Known known Known unknown Unknown unknown….
System optimization and balance
XFT upgrade as it is: L1&L2
Examples of possible new ideas:(not in particular order)
SVT barrel pointer 3 Layer XFT + IMU SVT SVXonly for forward… SVT to improve high pt triggers…Bjets etc L1 Phi trigger … New L2 clustering… Jet/Met/Higgs-Mjet/Top-Mjet … New tau triggers at L2… …
Preparing a good productive workshop takes tons of real work: in the past 2 months, we have had 4 meetings dedicated to preparing for this workshop. Details see web talks at:March 31, April 14th and April 28th TDWG meetings,and May 5th trigger hardware meeting.
Trigger WorkshopPart I&II
Part I: General Issues Overall Strategy: One table or two tables? (different implementation) Study “Sensitivity vs inst. Luminosity”: for all important triggers Backup triggers: what prescale/luminosity range …etc Table Survey Find solution for important triggers with high growth term System level optimization/balance ScalerMon optimization …. add your items here.
Part II: Brainstorm session Encourage people to come up with new ideas (algorithm and hardware improvements) Already have a good list of new ideas … need to select the most promising ones… Bring physics and hardware people together
To physics groups: this is your last chance that you may get help from hardware improvements… please help!
Goals for May 12th Trigger Workshop
The central goal of the workshop is to understand where we are with the trigger system right now (including upgrades already in the pipeline), and what other upgrades we might consider, in order to get us to where we want to be. The workshop is going to be physics driven. The RunIIb physics and trigger committee has already identified the highest priority physics triggers we should keep at high luminosity. Our goal is to make sure that we can actually keep these triggers running at the highest luminosity, and if possible, even improve their performance or develop new trigger strategies, while optimizing the middle and lower luminosity ranges for other physics.
We will hear from each physics group what "where we want to be" means - for example, where do you see trigger issues that could prevent you from getting to the search sensitivity that you would like with 4-8 /fb? And where do you see possible improvements that could even improve your search sensitivity?
The best example is the Higgs search. With the attention being focused on the light Higgs, how do we ensure that we have the best shot for a discovery at CDF? Our upgraded trigger system is much more flexible now than most people know. Where can trigger improvements help to really improve our Higgs sensitivity beyond what we have so far estimated?
Talks at the May 12th workshop
Physics Background: Introduction: Ted Overview of Physics Triggers: Dave Higgs: Tom Junk SUSY/Other Exotics: Ming B Physics@high lumi: Kevin
Current Upgrade XFT upgrade status: Nils L2 XFT expected performance: Andrew L2A bandwidth (EVB/L3): Markus CSL/data logger: Frank Offline computing: Rick Snider
Possible Future Upgrade:
(1) L2 Clustering Current System: Monica L2 Jet triggers: Mary L2CAL hardware upgrade: Ted New clustering algorithm: Gene Higgs Physics motivations: Viktor
(2) SVT & forward tracking improvements Improving lifetime measurement: Marco new SVT upgrade: Paola SVT upgrade study: Laura 3 Layer XFT+IMU: Ben SVT barrel pointer: Jonathan
(3) L1 phi trigger Motivation & hardware: Matthew
The workshop was very successful, have learned a lot!
Some examples/highlights from the Trigger Workshop
-- just examples, not a summary. Details see web talk.
.Track/mu related:
e.g. CMX etc
L2CAL related:
e.g. MET+2JETsbackups
attack the problem at its root:
L2CAL upgrade idea
Rate estimate,Trigger survey &
Sensitivity vs inst. Luminosity study
XFT upgrade will help,The question is: by how much
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CMX triggers at L2: gone wildAndrew Ivanov has been developing a
macro tool to simulate XFT L2 stereo
track 3d-reconstruction. He is doing
studies for the CMX inclusive triggers
at L2… in progress…
Backup triggers at higher luminosity
“Backup”: the name is misleading
It is not 2nd class citizen. It is as important as the main trigger, if not more.
By its very nature, it usually has large growth term
If we are not careful, can dominate the trigger rates at higher luminosity
Backup Trigger Needed for L2A @ 3E32 (XMON)
ELECTRON_CENTRAL_8_L2_DPS SecVtx, elec. trig. eff., CEM uniformityMUON_CMUP8_DPS SecVtxJET_20,50,70,100 SecVtx, fakes, jet corrections, etc. … 240 HzMUON_CMUP8_DPS, MUON_CMUP8_NOL2 SLTB_SEMI_CMUP4_TRACK2_D120_DPS SLTB_SEMI_L3PS50_L2_TRK2_D120_L1_CMUP6_PT4 SLT 60 HzMUON_PS1000_L1_CMUP6_PT4, MUON_CMUP4 SLTW_NOTRACK XFT & track eff. 35 HzW_NOTRACK_NO_L2, L1_EM8 cal. trig. eff. 10 HzPHOTON_25_ISO_PASS4 jet corrections 20 HzJPSI_CMU2_CMX2_PS2 Momentum Scale 265 HzJPSI_CMUCMU2_PS2 Momentum Scale 300 HzUPSILON_CMUP_CMU_DPS Momentum ScaleUPSILON_CMUP_CMX_DPS Momentum ScaleDIELECTRON_CENTRAL_4 Energy Scale 90 HzDIMUON_CMUP4_CMX4 Momentum Scale 12 HzDIMUON_CMUPCMUP4 Momentum Scale 10 Hz
TOTAL: 365 HzTOTAL: 677 Hz
The RunIIb Backup Trigger ProblemVeronique Boisvert + Dave Waters
• A small selection of existing top & electroweak backup triggers fills up spare bandwidth.• Some hard work required to figure out which of these we really need at high luminosity.
overlap with mainline signal
triggers ~ 10-20%
The Trigger Survey
• We’ve actually had a (surprisingly ?) good response : ~2/3 of non-B triggers. Some B triggers
have been filled. • We are starting to mine the data
Names attached to triggers - very useful ! A few clear statements can be made about backup trigger requirements at high luminosity. A large number of “unknowns”. But at least we can prioritise them by rate and seek to get the
most important studies done first.
Please help us to finish the trigger survey!
• Thanks to the survey contributors so far: Kevin Pitts, Simone Donati, Anyes Taffard, Oscar Gonzalez, Mary Convery, Chris Hays, Andrew
Hamilton, Robert Blair, Sasha Baroiant, Veronique Boisvert, Larry Nodulman, Beate Heinemann, Chris Neu, Tom Wright, Oliver Stelzer-Chilton, Jonathan Lewis, Jiyeon Han, Pasha Murat, Ambra Grisele, Mario Campanelli, Alberto Annovi, Andrei Loginov, Tara Shears, Andrea Bocci, Rolf Oldeman, Cheng-Ju Lin, Sarah Budd, Jonathan Efron, Aidan Robson, Sasha Pronko, Stefano Torre
https://b0www.fnal.gov/internal/ops/trigger/vsorin/trigpathuserinfo.html
Limitations of existing L2CAL
Existing L2CAL has worked well in the past As luminosity increases, starts to show “pacman’s age” -- Each cluster starts with a seed tower
-- All shoulder towers that form with the seed tower a contiguous region are added to the cluster -- The size of each cluster expands until no more shoulder towers adjacent to the cluster found… -- Seed selection algorithm “favors” lower phi and eta -- found cluster location is the seed location
Can form large fake cluster(s) due to CAL occupancy at high lumi… First problem showed up with ROF (see TDWG talks at June 25, 05) Seed location is not necessarily the cluster center Does not calculate the MET/SUMET at L2, only use L1 MET/SUMET Raw trigger tower energy information not available to L2 CPU …
For details on limitations, see TDWG talks on April 14th, 06, and June 25th, 05.
A brief history of recent L2 Jet trigger
-- the rise and fall, then rise …
More than a year ago, it became clear that the L2 Jet trigger has a large growth term with luminosity. We knew it was due to activities in the Ring-Of-Fire.
Early last summer, we learned that it was due to too many shoulders in the ROF to cause L2CAL finding large/huge fake clusters (hardware algorithm limitation)
Once the shoulders are removed from ROF, the situation improved dramatically…(~ up to 100E30 back then)
However, as luminosity went higher, the high growth term comes back again…
Ntow=70
ET=121
eta=18, phi=19
*
Why L2 JETs trigger rates grow up so fast?
This is at luminosity around 90-120E30 … Details see June 24, 2005 TDWG talks
Example: L2 JET improvements by kill ROF
JET40:Table 3_02
JET40: Table 3_04
JET90: Table 3_04
JET90:Table 3_02
An old slide from my June 24, 05 TDWG
talk: JET trigger long term issues
L2 JETs should drop significantly by ROF removal so far, JET90 means ~ 90% junk at high luminosity (Junk Enhanced Trigger) As luminosity increases, do we need to worry about the other
region (plug)? What could happen at, say, L > 2E32? * if happens to plug, could “eat/swallow” central jets alive at L2 Do your study early, as long as we understand any potential
problem early enough, we know we can take care of it !…
We warned people last June… turns out it is true…
example
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L2 Jet15_PS25
L2 Jet40
L2 Jet60 L2 Jet90 (now driven by Jet20 at L1)
Where we are now (table 4_00)…
Tip of iceberg?
w/ and w/o ROFTakes off again
nb Hz ovl nb Hz
Central Electron CEM8_PT8 3259 978 1 CEM18_PT8_A_R 96 29
Central Muon CMUP6_PT4 7437 2231 1 CMUP6_PT16 285 86
Muon Extension CMX6_PT8_CSX 3272 982 1 CMX6_PT15_JET10 200 60
Single Jet/Electron-70 JET20 2800 840 0.37 JET90_NOROF 40 12
Single Isolated Photon EM12 5000 1500 1 PHOTON_25 123 37
Missing Et MET25 8045 2414 1 MET35_JET5 79 24
e-central e-central TWO_CEM4_PT4 3855 1157 1 CEM4_CEM8 50 15
e-central mu-central CEM4_PT4_&_CMU1.5_PT4 2000 600 1 CEM8_CMUP4+CEM4_CMUP8 8 2
e-central mu-extension CEM4_PT4_&_CMX1.5_PT4_CSX 450 135 1 CEM8_CMX4+CEM4_CMX8 16 5
e-central e-plug TWO_EM8 3400 1020 1 CEM4_PEM8 137 41
mu-central mu-central TWO_CMU1.5_PT4 2000 600 1 CMUP4_CMUP8 4 1
mu-central mu-extension CMU1.5_PT_4_CMX1.5_PT4_CSX 700 210 1 CMUP4_CMX4 6 2
e-plug mu-central EM8_&_CMU1.5_PT4 700 210 1 CMUP4_PEM8 13 4
e-plug mu-extension EM8_&_CMX1.5_PT4_CSX 160 48 1 CMX4_PEM8 20 6
Tau+electron CEM8_PT8 3259 978 0 CEM+TAU 158 47
Tau+muon central CMUP6_PT4 7437 2231 0 CMUP+TAU 106 32
Tau+muon extension CMX6_PT8_CSX 3272 982 0 CMX+TAU 122 37
Plug e + Missing Et EM12 5000 1500 0 MET15_PEM20 50 15
Super Photon-70 JET20 2800 840 0 EM70 60 18
Di-Gamma/Z-notrack EM12 5000 1500 0 TWO_EM_16 17 5
Top Multijet JEY20 2800 840 0 FOUR_JET15_SUMET175 57 17
TOTAL 12395.8 TOTAL 495
Level 1 Level 2
Run IIb main Physics TriggersSt
raw
Tab
le @
3E
32
Was estimated 40 nb for JET90 at 300E30.likely higher
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Examples of other triggers using JET at L2
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BJET15_D120_JET10_ETA1.8
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CJET10_JET10_L1_MET25(MET+2JET HIGGs trigger)
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CJET15_L1_BMU10_BSUR_TSU0 FOUR_JET15_SUMET175
Why we need to think about improving L2 clustering?
Important MET/JET related triggers have high L2 growth terms at high luminosity with fake clusters …
Large fake clusters will reduce eff for triggers require multi-jets (such as top_multi-jets) at higher luminosity
Current MET threshold is already hurting HIGGs physics Need to improve tau triggers at L2 for HIGGs physics Can we improve isolation triggers at L2? The bandwidth we gain helps other triggers
…
Is there an easy way to upgrade L2CAL?
With Pulsar system, it is possible… Pulsar was designed as universal interface board To interface with DIRAC output (or DCAS input), just need a new
mezzanine card design… The idea is to send all the raw 10-bit trigger tower energy (LSB: 0.125
GeV) information into L2 CPU via Pulsars, then let CPU do the actual clustering (“offline-like”)…
Clustering much more robust against high occupancy
(large fake clusters can be avoid easily) MET calculation can be done at L2 with 10-bit info. (currently directly
from L1, based on only 8-bit info) Would be the first time making all trigger tower energy info available
to L2 CPU: a big step forward for L2 triggering at CDF
Proposal for L2CAL upgrade
Goals Significantly improve JET/MET trigger purity Enhance Higgs/exotics search sensitivity…
How Develop a parallel L2CAL path using Pulsars Send raw full 10-bit resolution trigger tower
energy information directly into L2 CPU Do software clustering inside the CPU Full resolution MET/SUMET at L2 Commission done in pure parasitic mode
Details see May 12th workshop talks.
•This proposal will be reviewed by end of June, along with a few other ideas. Review committee chair is Nigel. Decision will be made by 4th of July.
L2CAL
“Young man, if cross section is so low, increase the luminosity” -- Hans Bethe
After ~ 20 years hard work by many great people, CDF as an experiment has just reached its peak performance… the best is yet to come !
Triggering at ~300E30 will be still tough, but we can do it if we are willing to
Strategy to get there: First push current table performance up to ~200E30 Once XFT upgrade is done, can go beyond 200E30 with RunIIb triggers L2CAL upgrade may take us beyond 250E30 Reaching 300E30: may depend on how to handle backup triggers Other possible improvements could allow us to further optimize physics
triggers at different luminosities (see Alberto’s talk next, and trigger workshop talks)
Please come to Trigger Mini-workshop tomorrow morning!
Trigger mini-workshop tomorrow: First, Larry will tell us the history of CDF trigger: how did we get here?
Trigger mini-workshop tomorrow: At the end, Luciano will tell us his new thoughts on RunIIb trigger table…
Agenda for trigger mini-workshop tomorrow (9am-noon)
Introduction Ted Historical Perspective Larry Muon Trigger Eric SVT status and future Paola Isolation Trigger: status and future Bob OCD triggers at high lumi Regis Exotics triggers at high lumi Ming New thoughts on High Lumi Table Luciano Discussion ALL
Backup materials
For those who are interested in the details of the May 12th trigger workshop, please look at web talk.
More will be discussed at tomorrow mini-workshop Please respond to the Trigger Survey… you don’t
have to be an trigger expert to do it ! As long as you are doing analysis, your comment will be useful to us.
The rest are some slides on technical details for L2CAL upgrade… from May 12th workshop.
Improving L2 ClusteringPaola & Ted --Trigger Workshop, May 12th, 2006
Limitations of the existing L2CAL and how to
improve it? Is it possible? -- current L2 system is flexible enough What’s involved at technical level? Can we justify it? -- motivations Summary
What’s involved?-- only CAL related shown: concept
L1CAL
L2CAL
Calorimeter10 bits tower energy
10 bits tower energy
288 LVDS cables
Only 8 bits tower energy used by L1CAL
L2CPU
L2 Pulsar crate
L2CAL Pulsar crate
L2 CPU for commission
(1) A copy of input signal(2) New mezzanine: 4 cable/card(3) 18 Pulsars/AUX with new input firmware(4) 6 Pulsar/AUX SLINK mergers(5) Some simple online code(6) New clustering algorithm code
How to copy the input signal?-- for parasitic running,
crucial for commissioning
In principle, one could design a special splitter board. Or can use LVDS multi-drop property to get a copy:
DIRACdriver
DCAS
receiver
Pulsar mezzanine Receiver (no termination)
100 ohm
Need to make longer LVDS cablesActual cabling needs to be clean: with help from JDL
DS90C031
New mezzanine card design
Could use one small FPGA on mezzanine, to receive 4 cable inputs: 4 x 40 input signals (input is running at cdf clock). Simple firmware to push the data (40 bits wide) into Pulsar DataIO FPGA.
How to have 4 cable inputs per mezzanine (w/ option to
enable or disable termination)
Mezzanine card design concept
FPGA
LVDS/TTL chips
Cable connector
Pulsarside
Rack door
Cost estimate:
72 needed ~ 100
< $300 per card
(dominated by FPGA)
< $30K for mezzanine
~2 weeks engineer time
25 AUX cards
+ long cables
Total cost of the project:
< ~ $50K
Have just enough spare Pulsars to do this job
40
EM HAD EM HAD
10bits x4 =40 @ cdfclkinput data per cable
JTAG
Pulsar
front panel
Pulsar Cluster (1 Pulsar: 4 mezzanine x 4 cable = 16) x 18 = 288 input cables total
Pulsar x9
Pulsar x9
Pulsar Crate 1
Pulsar Crate 2
144 cablesfrom DIRAC
one 40-bit word/cable
144 cablesfrom DIRAC
9 slink outputs
9 slink outputs
Pulsar Slink merger x6 PC
Latency after L1A: ~ 4 to10 us, range depends on detail implementationNote: unlike other L2 paths, CAL data already available at L2 input upon L1A
Raw data size w/o suppression: 288x40/8 ~1.5KB per evt. With some overhead, < ~ 600 slink words maximum
w/ suppression, data size should be much less.
New Cabling at trigger room
L2 CAL crates
L1CAL crates
Under the floor
Not terminatedon pulsar mezzanine
Possible new pulsar crate locations
L2 Decision
crate
Commissioning can be done in pure parasitic mode, using the spare decision CPU,along with a copy of all other L2 data paths information
Above the racks
What it takes?-- need a few good men/women
To do it right and fast (~ half year), need ~ 4 young people full time for half year. Postdocs/students.
New mezzanine card design/firmware: ~ 2 months work including design, PCB turn around time, firmware, and testing Pulsar DataIO input firmware: ~ 1-2 months work Online code: ~ 1-2 month work Clustering algorithm optimization: ~ 1-2 months work with the goal of < ~20-30 microseconds algorithm time on average…
All can be done in parallel. The rest work is the actual commissioning…ALL can be done in pure parasitic mode, no down-time needed. This is my estimate, based on the experience in the past n years,assume ~ 4 good young people, FULL time for half year
Manpower on hardware/software assumption: anyone interested contact usMezzanine card design: Ted/Mircea (UC engineer), firmware: Marco Piendibene from PisaPulsar DataIO firmware: Marco PiendibeneOnline code and hardware testing: one Ph.D student (from Pisa or UC)Clustering algorithm optimization: one Ph.D student (from Pisa or UC)Overall: one ~postdoc level person to lead the project and overall commissioning
Some comments on hardware/software/manpower
Pulsar based L2 system is more flexible than people know
-- it is a LEGO game Perfect project to attract good new students and postdocs Have tons of experience on Pulsar hardware/firmware/online software/CPU
software/commissioning. Many experts still around to help There are faster PCs out there now… (current one is > 2 years old) Pulsar can do pre-processing (ET sorting, thresholds, SUMET/MET…) if
needed. Can do even more… hope there is no need. Will need to order more Pulsar AUX cards (simple PCB)… used for L2
decision upgrade, SVT upgrade, and XFT upgrade… Algorithm code performance is the key: work started! see Gene’s talk…
If needed, some can be implemented in Pulsar firmware. Currently, entire L2 algorithm time is only < ~ 1 microsecond. If more
performance is needed for clustering, can order faster PCs. we have just enough spare Pulsars for this job. keep this in mind: we may
not be able to do all of the other new ideas ... unless we order more.
Comments on Motivation
First and simplest, probably the strongest reason:
To survive!With new cluster upgrade at L2, many
Jet/Met related trigger rates should be reduced significantly (closer to the rates at L3) …
“But my triggers don’t use JET/MET, why should I care?” ---
You really should. Your analysis may have nothing to do with clustering, but your triggers are: the saved bandwidth from Jet/Met triggers will be used by your triggers.
(e.g. with less prescale or deadtime)
Second, to improve our physics sensitivity “beyond baseline”
Higgs Exotics Top: top_multi-jets will benefit
from this (better signal eff at higher lumi)
…
Hard to get solid estimate on final sensitivity gains in short time…as real sensitivity is a complicated thing for complicated analysis.
This is where we encourage people to do thinking/study… see next
More comments on Physics motivations
Higgs/exotics physics triggers should benefit from this, by how much? Is it really possible to improve Higgs sensitivity by new clustering? Top mulit-jets trigger should benefit from this, by how much? MET turn on should be improved …how much? (see Viktor’s talk) JET efficiency turn on should be improved … how much? (Gene’s talk) Clustering inside CPU should improve the location of the center of jets --- better Bjets matching (with SVT)…. By how much? Combined with ~3-d tracking info, can we improve tau triggers at L2? Can we do better for Isolation this way? By how much? … add your ideas /comments/questions here…
Chicken and egg issue: Hardware folks want to see if this is really worth doing from physics point of view,Physics groups want to see if hardware folks are really serious about this…Let’s work together!
Jet related L2 triggers L2_BJET15_D120_DPS L2_BJET15_D120_JET10_ETA1.8 L2_CEM12_ISO_&SUMET20_&_TWO_JET3_ETA1.8 L2_CJET10_JET10_L1_MET25 L2_CJET15_L1_BMU10_BSUR_TSUO L2_CJET15_PS24 L2_FOUR_JET15_SUMET175 L2_JET15_PS25 L2_JET40 L2_JET60 L2_JET90 L2_TWO_JET15_ETA1.5_&_TWO_TRK2_D100_DPS L2_TWO_TRK2_D100_&_BJET15_&_MET15_DPS L2_TWO_TRK2_D120_&_THREE_JET10_SUMET90_DPS L2_Z_BB_BJET_OS L2_Z_BB_BJET_SS In the future: MET35 --> MET35_JET5
Summary Pulsar-based L2 system is more flexible than we know We only have ~1fb-1 data now, much more yet to come Let’s be prepared for higher luminosity running and push real hard now to
improve our Higgs/exotic triggers (even luck favors those who are prepared) We may still have a chance! This is the nature of this game in HEP Perfect time for young people to get deeply involved, to have big impact on a
big mature experiment --- the sense of “playing with the experiment”
This should be reviewed by a committee of course… to see whether it is really worth doing…
Can a decision be made on this before end of June. ?
Four important related talks: (0) Monica’s talk on current L2CAL capability & limitations (1) Mary’s talk on threshold study (2) Gene’s initial results on clustering algorithm in CPU (3) Viktor’s results on L2 MET calculation and impact on Higgs triggers