Liang HAN University of Manchester
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Transcript of Liang HAN University of Manchester
December 31th, 2002 Liang HAN 1
Liang HANUniversity of Manchester
Central Fiber Track Trigger System
I. CFT & CTTT
II. Simulator: l1ft2b
III. First real L1CTT
IV. Run2a
V. Run2b
VI. Summary
December 31th, 2002 Liang HAN 5
I. Central Fiber Track Trigger
a) 8 cylinders: Layer A,H
b) Axial doublet fibers per Layer
c)
d) in rphi: 80 Sectors, 10 Octants
Provide pT Track Trigger in xy-plane
December 31th, 2002 Liang HAN 6
Alignment cylinders: Fibers of 1 super Layer/sector:
Pictures of CFT Pictures of CFT
December 31th, 2002 Liang HAN 8
DDoublet[k] = oublet[k] = { !inner(k-1) & outer(k) } ||{ !inner(k-1) & outer(k) } || innerinner((k)k)
CFT axial doublets are formed using two interleaved CFT fiber layers as follows:
k+1
k
k
k+1
k-1
k-1
increasing phi(looking NORTH at SOUTH face of detector)
CFT Axial Doublet
December 31th, 2002 Liang HAN 9
CTTT Algorithm
Stable charged from (0,0) in 2T Bz
where in Dzero, in cm and pT in GeV
ii rpT
kQ
0
0 5.0
ir006.00 k
pTNiFiber Fibersi 2
][
December 31th, 2002 Liang HAN 10
Pre-programmed Trigger lookup table: 8 Doublet Equation
(A,B,C,D,E,F,G,H)
Ptmin
(GeV)
Ptmax
(GeV)
Intacc relacc
0 1 1 1 1 1 1 0 -.161E+02-.119E+02 25160 0.357E-02
5 5 5 5 4 3 1 0 -.351E+01-.307E+01 92610 0.132E-01
-2 -2 -1 -1 -1 -1 0 0 0.18E+02 0.525E+02
57220 0.813E-02
11 12 12 11 10 7 4 1 -.169E+01-.162E+01 19890 0.283E-02
… … … … …
Hit Paten )/1/1(
2
maxmin ptptpT
“Equation”
December 31th, 2002 Liang HAN 11
1) Exclusive pTbin:
2) Inclusive Terms:
PT1 pT>10PT2 10>pT>5PT3 5>pT>3PT4 3>pT>1.5
TTK10 >=1 PT102TTK10 >=2 PT10
TTK5 >=1 PT52TTK5 >=2 PT5
… …
Trigger pTbin & AndOr Terms:
December 31th, 2002 Liang HAN 13
Simulate CTTT system, follows Trigger framework as close as possible, aim to Run2b Algorithm study:
1) CFT axial hits(ADC cut)2) Trigger Cluster, i.e. Doublet/Singlet (Algorithm)3) different Equations (Algorithm)4) Equation-Cluster match5) matched tracks reported
II. Simulator: lft2b
CTTTCTTTframeworkframework
SimulatorSimulator
l1ft2bl1ft2bOnlineOnline
platformplatform
December 31th, 2002 Liang HAN 14
III. First real L1CTT
L1CTT started working this November, many strange of online Platform have been observed.
l1ft2b is considered as close to the frameworkas possible, so a good tool to understand what’swrong. Focus on highest pTbin PT1
December 31th, 2002 Liang HAN 15
Phi distribution of online TTK10 triggered events:Phi distribution of online TTK10 triggered events:
Octant 2&7 screwed upOctant 2&7 screwed up!!!!
what understood
December 31th, 2002 Liang HAN 16
MaxpT distribution of MaxpT distribution of l1ft2bl1ft2b for for 37473747 events triggered by events triggered by online TTK10online TTK10
20492049 out of out of 37473747, why?, why?
what not understood yet
December 31th, 2002 Liang HAN 17
IV. Run2a Doublet EquationIV. Run2a Doublet Equation
PT1 eff of current online on single muon from(0,0)PT1 eff of current online on single muon from(0,0)
December 31th, 2002 Liang HAN 18
Problem of current EquationProblem of current Equation
Current online(Current online(nominalnominal):):• 80 sectors: 80 sectors: identicalidentical• designed Layer position: designed Layer position: eg HX eg HX 51.5cm51.5cm• tracks from (tracks from (0,00,0) )
As-builtAs-built::• sectors: sectors: individualindividual!!!!!!• Layer shift: eg HX Layer shift: eg HX 52.0cm52.0cm• beam-spot: eg beam-spot: eg (-0.3,0.339)mm(-0.3,0.339)mm
problem:PT1 eff of problem:PT1 eff of nominalnominal on pT=15 single muonon pT=15 single muon99.199.1% % 61.161.1% % (+20.7% PT2)(+20.7% PT2)
answer: new answer: new as-builtas-built equations(Graham Wilsom) equations(Graham Wilsom)
December 31th, 2002 Liang HAN 19
New as-built EquationNew as-built Equation
check check as-builtas-built with data: 143 recod dimuon(pT>15) with data: 143 recod dimuon(pT>15)
216
202
)60,(#
)01.0,1(#
M
PTPT1 effPT1 eff 93.593.5%%
December 31th, 2002 Liang HAN 20
Sample Equation PT1 efficiencyMC mu(15),mb0,
no ADC cutnominal ~99.5%
MC mu(15),mb7.5,
no ADC cutnominal 98.5+/-0.19%
MC mu(15),mb7.5,
1.5pe cutnominal 97.6+/-0.24%
Dimu Data (pT>15) as-built 93.5+/-1.7%
MCMC expect ~ expect ~9999% PT1 eff with current luminosity, % PT1 eff with current luminosity, but but as-builtas-built only gives ~ only gives ~9393% on data, i.e. % on data, i.e. 66% ineff % ineff
December 31th, 2002 Liang HAN 23
Causes of ineff:Causes of ineff:• multiple scattering: multiple scattering: unlikelyunlikely, ineff independent with track pT, ineff independent with track pT• Doublet Veto: Doublet Veto: unlikelyunlikely, 1D-shift mostly occur at D Layer, 1D-shift mostly occur at D Layer• beam shift: beam shift: unlikelyunlikely, include 250micron smearing , include 250micron smearing • inperfect CFT geometry: inperfect CFT geometry: possiblepossible, some fibers are not parellel to z, some fibers are not parellel to z
Risk: the number of equations increase, eg Risk: the number of equations increase, eg
nominal 16k nominal 16k to current to current as-built 18kas-built 18k fake ratefake rate
December 31th, 2002 Liang HAN 24
V. Run2b developmentV. Run2b development
Run2a Run2b
Luminosity 2E30 2E31
Bench(ns) 396 132
No of mb ~2 ~6-7
Bad news: we may never come to 132ns in Run2bBad news: we may never come to 132ns in Run2b
December 31th, 2002 Liang HAN 25
Weakness of Doublet AlgorithmWeakness of Doublet Algorithm
A) A) Veto:Veto: pT=15 muons in Pythia mb7.5, Doublet PT1 eff ispT=15 muons in Pythia mb7.5, Doublet PT1 eff is
97.697.6%% (~99% in mb0) (~99% in mb0)
B)B) Fake: Fake: pure Pythia mb7.5 events, from random noise Doublet will havepure Pythia mb7.5 events, from random noise Doublet will have
11%% triggered by fake PT1triggered by fake PT1
L1 can only survive with greater than L1 can only survive with greater than 0.20.2% fake in % fake in Run2b luminosityRun2b luminosity
Doublet can’t survive in Run2b luminosity!!
December 31th, 2002 Liang HAN 26
Worst-case scenario:Isajet
A)A) Eff lost due to Veto: Eff lost due to Veto:
B)B) Fake rate: Fake rate:
December 31th, 2002 Liang HAN 29
16 Singlet
Advantage:A) no Veto: efficiency unchanged with mb
B) reject fake: finer Trigger Bin
Problem: PT1 part, with nominal+1.5pe fiber efficiency cut
4800k!!! 300 times FPGA resources of current online Run2a
December 31th, 2002 Liang HAN 30
Trim Equations
Tried and tested 13 different algorithms, kill most of themand come to the “final” choice :
A) Mixed Algorithm: pT>5 part, pure 16 Singlet, i.e. “abcdefgh” pT<5 part, Singlet-Doublet mixture, i.e. “ABCDefgh”
B) tricky pruning: to get rid of low acceptance ones
December 31th, 2002 Liang HAN 31
Tricky pruning
1) Remove equations with Doublet missing2) Cut on “intacc”(MC hits)3) Remove/combine redundancy
Come to “16v5PT12_acc200rr” and “12v4PT34_acc10rr”
December 31th, 2002 Liang HAN 32
Result of latest Run2b Algorithm
“abcdefgh”
“ABCDefgh”
• 98% PT1 eff, and 0.031% fake in pmb7.5
• Total come to 31k, risk of overflow FPGA
December 31th, 2002 Liang HAN 35
VI. SummaryVI. Summary
CTTT simulator:
online CTTT: start to work, but
Run2a: real as-built equation is under development, need more Zmumu data for calibration
Run2b: new algorithm is suggested; need Run2a inform to make Run2b real
CTTTCTTTframeworkframework
SimulatorSimulator
l1ft2bl1ft2b
SimulatorSimulator
l1ft2bl1ft2bOnlineOnline
platformplatform why?why?