HOW TO EXPAND THE PHYSICS REACH WHILE SAVING MONEY

FAST-TRACK COLLABORATION

Start at Pisa in 1999, funded by Gruppo V: INFN, Dip. Fisica, Dip. Ing. Informatica, SNS - Pisa:A. Annovi, R. Carosi, M. Dell’Orso, P. Giannetti,G. Iannaccone, G. Punzi Offline-quality tracks @LHC Level 1 output rate

Joined in 2002:INFN, Dip. Fisica, Dip. Ing. Informatica, SNS - Pisa:P. Catastini, V. Cavasinni, V. Flaminio, T. Del Prete,C. Roda, G. Usai, I. VivarelliINFN, Dip. Fisica Roma: S. Giagu, M. Rescigno, L. ZanelloUniversity of Chicago: M. Shochet

Interested to join:University of Geneva: X. WuArgonne National Laboratory: J. Proudfoot

Co-operating on software algorithms:INFN-Dip. Fisica - Genova: F. Parodi

Co-operating on standard cell chip:Dip. Fisica - Ferrara: R. Tripiccione

P. Giannetti CSN1 3/2/2003

SVT Collaborators

Fast-Track Offline-quality tracks made

available to LHC L2 triggers, @L1 output rate.

Outline:

• Fitting FTK in the DAQ

• Working principles

• Physics reach and trigger strategies

• QCD multi-jet background

• Size and performance

Fullresolution

hits

Lowresolutionsuper bins

Tracking in 2 steps: find Roads,

then find Tracks inside Roads

Road

Super Bin

Road =Pattern

Road

PIPELINE

LVL1LVL1

Fast Track +(Road Finder) Fast Track +(Road Finder)

EVENT BUILDEREVENT BUILDER

CPU FARMCPU FARM

CALO MUON TRACKER CALO MUON TRACKER

BufferMemory

ROD

BufferMemory ROB ROBROB

offlinequalityTracks:Pt >1 GeV

Ev/sec = 50~100 kHz

L2 Algorithms

fewCPUs

FEFE

CMSinner detector

1000 tracks||< 2.5

Reconstructed tracks Pt> 2.0 GeV

30 minimum bias events +H->ZZ->4

Htt events: 1000 tracks in barrel 120 tracks Pt> 2.0

GeV

AM = BINGO PLAYERS

HIT # 1447

PATTERN NPATTERN 1PATTERN 2

PATTERN 3

PATTERN 5

PATTERN 4

Dedicated device - maximum parallelism:• Each pattern with private comparator• Road search during detector readout

The Event...

The Pattern Bank

TRACKING WITH PATTERN MATCHING

AM the Associative Memory

Bingo scorecard

ASSOCIATIVE MEMORY: CHIP ARCHITECTURE

ONE PATTERN

FF FF FF FF

FF FF FF FF

FF FF FF FF

FF FF FF FF

word word word word

Layer 1 Layer 2 Layer 3 Layer 4

HIT

Patt 0

Patt 1

Patt 2

Patt 3

Ou

tpu

t Bu

s

HIT HIT HIT

1/4

A

M 1/4

A

MDivide into sectors

6 buses

6 buses

Pixels barrel SCT barrel Pixels disks

Barrel + Disks to build full coverage

AM input bandwidth = 40 MHz cluster/bus

AM input buses = 6 <cluster/event> cluster rate

Pix 0 1300 64 MHzPix 2 + extra 1200 57 MHzSC0 + extra 980 49 MHzSC1 + extra 1000 52 MHzSC2 + extra 980 49 MHzSC3 + extra 980 49 MHz

Ev/sec 50KHz

2 AM partitionsfor the whole Pix+Si tracker

More partitions as a backup option

Less partitions Less hardware

conservative estimates from inner-detector & pixel TDRs

20 9U VME boards – 3 types

SUPER BINSDATA

ORGANIZERROADS

ROADS + HITS

EVENT # N

PIPELINED AM

HITS

FASTRACK

BUFFERMEMORY

BUFFERMEMORY

FrontEnd

Tracker

DO-board

EVENT # 1AM

-board

50~100 KHzevent rate

GB

Few CPUs

Offline quality Track parameters

The AM board

• Track confined to a road, fit is simple

• Linear expansion in the hit positions xi: – = k (cik xi)2 final cut

– d = d0+ai xi = 0+ bi xi Pt = …

• Fit reduces to a few scalar products fast

• Constants from detector geometry– Calculate in advance– Correction of mechanical alignments via linear

algorithm • fast and stable• A tough problem made easy !

Test of the linear fit using a fast simulation of the ATLAS Silicon Tracker Genova group: M. Cervetto, P. Morettini, F. Parodi, C. Schiavi, presented on 20-Nov-2002 at PESA

(d0) = 17 m

Track parameterresidulas

Track parameters:fit value vs. true

/N

Z bb

bbH/A bbbb

tt qqqq-bb

ttH qqqq-bbbb

H/A tt qqqq-bb

H hh bbbb

H+-

tb qqbb

Offline-quality b-tagging:Hadronic or soft-lepton

events reach of b’s

ATLAS with pixel only b-tag @LVL2 is less efficient

with FASTRACK offline b-tag performances @LVL2

ATL-

DA

Q-2

000

-03

3

ATLA

S T

P

31/3

/2000

0.6

100

10

1000

b

Ru

ATLAS: Staging of Trigger/DAQ system

-- Deferrals limit mainly available networking and computing for HLT-- Large uncertainties on LVL1 affordable rate vs money (component cost, software performance, etc.)

No room for safety factor

LVL1 LVL1 rate LVL1 rate HLT HLTselections (kHz) (kHz) selections Rate(examples …) L= 1 x 1033 L= 2 x 1033 (Hz) no deferrals extrem deferral

(2/3 of CORE)

MU6,8,20 23 0.8 20 2MU6 --- 0.2 210 ~40

EM20i,25,30 11 4.4 e25i 2EM15i,15,20 2 1 2e15i ~40 60i 220i ~40 J180,200,200 0.2 0.2 j400 3J75,90,90 0.2 0.2 3j165 4J55,65,65 0.2 0.2 4j110 ~25

J50+xE50,60,60 0.4 0.4 j70+xE70 ~20

Tau20,25,25+xE30 2 2 35+xE45 ~5

MU10+EM15i --- 0.1Others 5 5 others ~30(pre-scaled, etc.)

Total ~ 44 ~ 15 ~200

From Fabiola Gianotti, LHCC, 01/07/2002

CMS: Trigger Table @ 2x1033 cm-2s-1

Trigger Level-1 HLT Thresh. Rate Thresh. Rate (GeV) (kHz) (GeV) (Hz)

Inclusive iso e 29 29 33Inclusive iso 29 3.3 80 4Di-e 17 17 1Di-17 1.3 40,25 5

Inclusive iso 14 2.7 19 25Di-3 0.9 7 4

Inclusive -jet 86 2.2 86 3Di--jet 59 1.0 59 1

Jet*Etmiss 88*46 2.3 180*123 5

1-, 3-, 4-jets 177,86,70 3.0 657,247,113 9Inclusive b-jet 237 5

e*jet 21*45 0.8 19*45 2

Other 0.9 10

TOTAL 16.0 105

From CMS TDR 6, 15/12/2002

ATLAS+FTK: Trigger @ 2x1033 cm-2s-1

Level 1

soft : + very soft jets: ~ 2 kHz PT> 6 GeVjet1 PT > 25 GeV + || < 2.5jet2 PT > 10 GeV + || < 2.5

hadron: 3 soft jets: ~ 4 kHzjet1 PT > 70 GeV + || < 2.5jet2 PT > 50 GeV + || < 2.5jet3 PT > 15 GeV + || < 2.5

ET > 200 GeV

Level 2

Mbb50: 2 b-jets + Mbb > 50 GeV 3-b: 3 b-jets

Mbb50 on level-1 soft : ~ 160 HzMbb50 on level-1 hadron: ~ 50 Hz3-b on level-1 soft : ~ 10 Hz3-b on level-1 hadron: ~ 10 Hz

Even

ts

Z b-bbar Important b-jet calibration tool

Mbb(GeV)

Level 1: soft or hadron

Level 2: Mbb50

significances:(soft ) S/B 60(hadron) S/B 20

CDF Run II

(S/B = 35)

Cdf/anal/top/cdfr/4158

Even

ts

Mbb(GeV)

2fb-1

ATLAS + FTK 20fb-1

Title:/afs/cern.ch/user/t/tdrhiggs/public/HIGGS-TDR/contrCreator:HIGZ Version 1.25/05Preview:This EPS picture was not savedwith a preview included in it.Comment:This EPS picture will print to aPostScript printer, but not toother types of printers.

bbH/A bbbb

Analysis:4 b-jets |j|<2.5 PT

j > 70, 50, 30, 30 GeV efficiency 10%

L1: hadron (70,50,15) efficiency 25%L1: soft- efficiency 19%

L2: 3-b efficiency on hadron sample 18% L2: 3-b efficiency on soft- sample 8%

ATLA

S-T

DR

-15

(1999)

Effect of jet PT cuts is even worse with deferrals

MA (Gev)

tan

200

Pythia vs CDF RUN I data

Physics background Pythia Xsec study sample Data Xsec

pp bbbbbb 4 bjet+X 30 pp VH bbqq 2bjet+2jet 10 tt bbqqqq 2bjet+4jet 15

Multijet QCD backgroundShower Monte Carlos expected to underestimate data cross-sections.

IN CDF WE OBSERVE THE OPPOSITE ?

We are studying this background:

Different Monte Carlos: 1) Herwig vs Pythia2) matrix element calculations vs shower Monte Carlos

Hqq+HV 10 pb

6 + hadron 0.1 pb on tape2000 H/year

Hbb+Htt 1 pb

6 + hadron 0.05 pb on tape1000 H/year

gg H 30 pb

61 pb on tape20000 H/year

bb

bb

bbqq

bbbbqqqq

bbqqbb

bbbb

bbH/Abbbb

CDF

ATLAS

More examples

qqH, VH bb+njets

L1: hadronL2: Mbb50

qqH

WH ttH Z0H

Efficiency % ~25

~25

~ 90

~35

ttH bbbb+njets, H+Z0 bb+bb

L1: hadronL2: 3-b

Electron Identification

Swapping trigger algorithms can reduce the trigger rate while increasing efficiency!

The sooner offline quality tracks are included in the trigger the greater is the final efficiency.C

ER

N/L

HC

C/2

00

0-1

7

The efficiency & jet rejection could be enhanced by using tracks before calorimeters.

With FTK tracks are ready on the shelf: using tracks is even faster than using calorimeter raw data!

0.4

0.5

0.6

0.7

0.8

0.9

1.

0 0.02 0.06 0.1 0.14

(QCD 50-170 GeV)

(H

(20

0,5

00

GeV

)

1

,3h+

X) L=2x1033 cm-2 sec-1

mH=500mH=200

TRK tau on first calo jets

Pix tau on first calo jet

Staged-Pix tau on first calo jet

0.007

0.004

TRK tau on both calo jets

Calo+TRK: (QCD)=10-3 (mH=500)=0.49 (mH=200)=0.45 T=170 ms

Calo+PXL: (QCD)=10-3 (mH=500)=0.42 (mH=200)=0.41 T=59 ms

HLT selection @ CMS H(200,500 GeV) 1,3h± + X) CERN/LHCC 02-26 CMS TDR 6 December 15, 2002

Calo tau on first jet

Thin Road Width: pix 1mm x 6.5cm Si 3mm x

12.5cm

Medium Road Width: pix 2mm x 6.5cm Si 5mm x

12.5cm

Large Road Width: pix 5mm x 6.4cm Si 10mm x

12.5cm

ATLAS Barrel (~CERN/LHCC97-16)

7 layers: 3 Pixel + 4 micro-strip (no stereo)

Cylindrical Luminosity Region: R = 1mm, z = ±15cm

Generate tracks (Pt>1 GeV) & store NEW patterns

1/4BARREL

10M

patterns

ATLAS configuration:12 detector layers – 5 •105 SB/layer128 chips/board PQ208 die: 16.32 mm2

What chips do we have now ?

Config. Technology Status Density(patt/chip)

CDF old full custom on-line 128 CDF old FPGA working 64CDF current FPGA designed 1000~ATLAS old FPGA under test 32ATLAS stand. cell 0.18 estimate (now) 11000ATLAS stand. cell 0.1 estimate (1999) 40000

International Technology Roadmap for Semiconductor 1998

2005: patt / 9U-board

XCS40XL (.13) 64x103

Virtex (.1) 330x103

Stand. Cell (.1) 5000x103

AM

-B1

AM

-B0

DO

5D

O4

DO

3D

O2

DO

1D

O0

CUSTOM BACKPLANE FOR SBS & ROADSIN THE PIPELINE

RO

AD

BU

S

on

P2

Gh

ost

Bu

ster

DO - DAQCONNECTION

The FTK CRATEC

PU

0C

PU

1

1/2 Barrel +

Disks

30M patterns

AM

-B2

AM

-B3

CPU

2C

PU

3{

AM

-B4

AM

-B5

Standalone program to produce hits from tracks, it includes:• multiple scattering• ionization energy losses• detector inefficiencies• resolution smearing• primary vertex smearing: xy=1mm z=6cm

Detector hits generated from (Pythia): • QCD10 sample: QCD Pt>10 GeV • QCD40 sample: QCD Pt>40 GeV • QCD100 sample: QCD Pt>100 GeV • QCD200 sample: QCD Pt>200 GeV

all samples + noise + <5 MB>.

Road finding 6 layers/7 (FTK simulation)

Fullresolution

hits

Lowresolutionsuper bins

Tracking in 2 steps: find Roads,

then find Tracks inside Roads

Road

Super Bin

Road =Pattern

Road

Nfits <Ncomb/road>x<Nroad/track>

13 comb x 34 roads = ~440 comb/track

1.4 comb x 4 roads = 6 comb/track QCD Pt102.3 comb x 6 roads = 14 comb/track QCD Pt407.8 comb x 9.5 roads = 74 comb/track QCD Pt10027 comb x 25 roads = 658 comb/track QCD Pt200

thin

thin

large

large

Pt 200

Pt 100

Pt 40

Pt 10

Step 2: Software Linear Fit Ncomb

/trk

658

74

14

6

Ntrk

/ev

17

16

10

8

L1 Trig

jet

jet

soft jet

soft

L1 Rate

200Hz

<2KHz

~5KHz

~20KHz

Fits/sec

2.2MHz

<3MHz

750kHz

1.5MHz

<8MHz

Full 3D fit

fit/s 0.6 MHz

2D Fit

fit/s 2.2 MHz

PIII 800MHz

2.5D Fit

fit/s 1.1 MHz

Htt 4400 fit/ev <latency> =

1ms max latency =

100ms

Pt 200 11200 fit/ev. <latency> =

3ms

only 8 CPUs (barrel)

Latency Test

Nfit

/ev

11186

1184

140

48

FTK finds roads with event rates up to 100 KHz.

FTK data organization/reduction allows full resolution track fitting with Pt>~1 GeV with low CPU usage.

More efficient LVL2 triggers:Lower LVL1 & LVL2 thresholds and CPU power saved!

FTK is very compact: 2 crates + connection to experimentb-jet tagging at rates 10-20 KHz:more Higgs physics !

FTK as a possible strategy for hadron collider triggers:offline-quality tracks at LVL2

Backup slides

SVT TDR ’96

Impact parameter

SVT simulated on real data superimposed to real offline

SVT just started

Real dataCDF run 127844

No alignment corrections

~ 45 m

~ 48 m

Independent Tests of QCD Production

Channels

• Direct production

• Flavor excitation

• Gluon splitting

• CDF ok• LEP ok

• CDF ? not ok ?• LEP not applic.

• CDF ? not ok ?• LEP F.S.R. only

Init. State Rad. 75%Fin. State Rad. 25%Phys. Rev. D 50, 5562 (1994)

CDF: Pythia compared to Herwig

6pb/GeV

30pb/GeV

PythiaHerwig

Direct production

g - splitting

Flavor excitation

Only Direct productiondoesn’t show differences!

Pythia is well tested at LEP, but only Direct Production can be well tested at LEP!

6jet of which 2b-jet PT>250 GeV: Pythia & Herwig

Direct production is negligible

Pythia Herwig

D,Ds

D0D0KK

BD0

BhhBsDs

*

• The natural implementation of the linear fit is coupled with hits selection made by dedicated hardware (Pisa group proposal). But could be also an important tool for the online software selection.

• The importance of the size of (assumed) linearity region has been studied in the cases:

– Large region (0</6, ||<0.5, |z0|<10cm): the

detector geometry gives the dominant contribution to track resolution ((d0) = 90

m).

– Smallest region (each possible pattern of modules has different tuning): good results ((d0) = 17 m), but big effort is requested to

tune all the detector. The memory needed in this case could be large: N possible patterns X 95 tuning constants (considering six layers) X 4 bytes (variables in float precision).

Conclusions (by M.Cervetto on linear fit)

Calorimet. LVL2 algorithm for Tau selectionEfficiency for H vs. output rateCMS-IN 2000-033

Tau Identification

0.4

0.5

0.6

0.7

0.8

0.9

1.

0 0.01-0.04-0.06-0.08-0.1 0.12 0.14 0.16

(QCD 50-170 GeV)

(H

(20

0,5

00

GeV

)

1

,3h+

X)

0.0070.003

L=1034 cm-2 sec-1

TRK tau on first calo jets

Pix tau on first calo jet

Staged-Pix tau on first calo jet

TRK tau on both calo jets

0.

0.2

0.4

0.6

0.8

1

0 25 50 75 100 125 150 175 200

Calibrated jet Et

Sele

ctio

n e

ffici

ency

Htt

bar

L=1033 cm-2 sec-1

1 jet

2 jet

3 jet

4 jet

25%

10 Hz

||< 2.5

Hadronic Htt selection @ CMS

Level 1

Level2: 4 jets Et>50 GeV

1 bjet: 10-15 Hz 50% efficiency

Composition of LVL1 soft sample

26% of the events have no b-quarks inside

74% of the events have at least a b-jet:13% direct production27.5% flavor excitation33.3% g splitting

23% of the events have at least 2 b-jet:13% direct production 3% flavor excitation 7% g splitting

===========================================

no-btagging:mjj>70 GeV Rate=1.2 ± 15% kHz

double b-tagging:mbb>70 GeV Rate=110 Hz

Level 2 rates: Pythia+ATLfastIdeal: b=100% c =0% u,d =0%

Real: b=60% c =10% u,d =1%

Mis-tag: b=100% c =10% u,d =1%

ATL-DAQ-99-014

# RODS # RODS 360O in 180O in

Pix 0 36 18Pix 2 32 16Pixdisk 16 8 SC0-3 44 22 SCdisk 48 24

TOT 176 88

Now: CDF-like configuration: 0.45 Gbit/s6 layers - 48000 250 wide SB/Layer

• full custom (.7) - 128 patt/chip- 16x103 patt/9U board

• XCS30XL (.35) - 128 patt/chip - 16x103 patt/9U board• XC2S200E (0. 186 lay) 50 euro/chip

- 300 patt/chip - 38x103 patt/9U board

• XC2V1000 (0.158 lay – 0.12 transistors)

- 1200 patt/chip- 153x103patt/9Uboard

• EP1C20F324C8 (0.1350 euro/chip- 1100 patt/chip

- 141x103patt/9Uboard• Stand.Cell (.35) - 1000 patt/40 mm2

• Stand.Cell (.18) - 4000 patt/40 mm2

• Stand.Cell (.13) - 16000 patt/40 mm2

The Associative Memory CHIP128 chips/board PQ208 (die:16.32 mm2 )

2005: LHC-like configuration: 4.Gbit/s 12 layers - 500000 SB/Layer

• XCS40XL (.13)- 64x103 patt/9U board

• Virtex (.1) -330x103 patt/9U board

• Stand.Cell (.1) - 5x106 patt/9U

boardInternational Technology Roadmap for Semiconductor 1998

CDF AM = 400 k pat. 4 milioni di pat.XC2S200E55 $/chip;14000 chips: 1.4 GLXC2V1000 200$/chip; 3500 chips: 1.4 GLStandard Cell 1000 chips; 200 + 200 ML