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Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia1
Calorimetria di ATLASCalorimetria di ATLAS
HADRONIC TILECAL
EM ACCORDION ECA
Barrel
ECC
ECA
Barrel
ECC
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia2
Fasi del CommissioningFasi del Commissioning
• PreCommissioning on surface• Commissioning in the Pit:
– Fase 1: Calorimetria LAr & Tile testati come entita` independenti – da ora fino all’estate 2006
– Fase 2: • Integrazione di LAr e Tile con i servizi: cabling, DCS, DAQ,
trigger +• Integrazione di LAr e Tile for cosmic ray run – fine 2005 fino a
fine 2006 (also indicated as LArg phase 3 commissioning)– Fase 3: Run di cosmici con il rivelatore di ATLAS
completo – inizio 2007
In vari periodi le diverse fasi si sovrappongo
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia3
LAr and Tile Barrel installation in pit completed on 10/12/2004
LAr and Tile Barrel installation in pit completed on 10/12/2004
LAr and Cryostate
TileCal
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia4
• Commissioning Phase 1 is constitued by 13 WP (Cable & Module installation & QC, FE readout electronics test, Electronic for Calorimeter Trigger, Cesium, Laser, DCS, HV-LV, ROD) • Commissioning is being taken care of by all Institutes.• Iacopo Vivarelli is responsible for the DAQ tools -> coordinates the commissioning effort
Since then we have been working to the commissioning of TileCal in standalone (Phase 1):
• Install F/E electronics, LV-HV, cables/fibres
•Debug the individual elements
•Cosmic ray runs
Commissioning Fase 1 Barrel TileCalCommissioning Fase 1 Barrel TileCal
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia5
Commissioning Fase 1 - TileCalCommissioning Fase 1 - TileCal
Stability test for FE electronics for readout and trigger, HV ps with Mobile DAQ in the pit; long duration test is now at about 65% of Barrel, problems found are being fixed, most of them connected to HV that are tested for the first time; During summer 1 expert week on june, trigger signal from towers sent to special FPGA cards to trigger on projective muons. First cosmic ray run in the pit Next expert (long) week 19-28 September: 12 Modules (10% Barrel) with Real ROD, whole DAQ chain including all trigger levels with dummy algorithms, monitoring, LV ps test on 4 of the tested modules, DCS for LV-HV and cooling. On the critical side are the LV ps, however the situation is getting better and we are still on schedule (LV ps installed by end of November)
May
November
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia7
Commissioning Fase 1 - TileCalCommissioning Fase 1 - TileCal
26 Ottobre Barrel moved at interaction point z=0 → beginning of phase 2. This movement has been shifted by 7 weeks with respect to previous schedules for delayes related to installation of toroid and ID services; No major worries for this delay however the schedules are being adjuasted.
ALL THE DATES I AM SHOWING ARE ALREADY SHIFTED BY TWO MONTHS
Beginning of 2006 - Start of phase 1 for EBC and than for EBA, installation to pit & commissioning phase 1 2006 will see: commissioning of Barrel phase 2 + commissioning EBC phase 1 followed by commissiong of EBA phase 1 the experimental pit will start to be very crowded thus the work in the pit is very carefully planned.
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia8
PreCommissioning– EndCap LAr PreCommissioning– EndCap LAr @Building B180 cold tests:
EndCap A Start of cool down - June 13
Detector filled with Lar - August 16
Ready for cold tests - August 22
End of test 25/9: but might need a few more days
Milano involvement:– HV tests (all subdetectors: EMEC, FCAL, HEC)– Time Domain Reflectometer (TDR) measurements: characterization of calibration lines
(EMEC)
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia9
HV DCS Control – LAr HV DCS Control – LAr
First prototype of Finite State Machine DCS control: HV control for EMEC LAr in ATLAS
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia10
Set up al B180 e USA15Set up al B180 e USA15
B180
7 HV crates for cold test of ECA in B180
The end of the ECA cold test (end of warm-up by Mid november) will be the end of the activity in B180.
HV setup (crates & workstation) moved to USA15 for the cool down and for the test with cosmics of Barrel first and EndCap later.
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia11
Set up al B180 e USA15Set up al B180 e USA15
USA15
8 ISEG HV Modules
First HV crates already in USA15 to perform stability test of HV ISEG modules Loard simulators
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia12
Commissioning Fase 1 – LAr Commissioning Fase 1 – LAr
Barrel: 3/32 electronic crates installed and tested so far: a few more crates partially equipped not powered yet. Test procedure established after some experience. Set of measurements: pedestals, calibration (ramp, delay runs),... Monitoring uses Athena and root
Endcap C:– Ready to be transported in the pit – After the endcap is in the pit (by end of November) and extended tile is completed next step will be the installation of the services
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia13
Commissiong Fase 1 LAr – integrazione dei servizi
Commissiong Fase 1 LAr – integrazione dei servizi
Endcap Services (A and C) installation under Milano responsibility: Design started beginning of August (~200 drawings!) and is now completed. A few issues with Tiles services clarified in the meantime. Formal approval expected within days The Collaboration congratulates for the work done
Next Steps: Service material (responsibility of BNL) is available due to the complexity of the system and the tight installation
schedule → preassemble and test using a mock-up in Milano. This allows to reduce time and costs A wedge of the mock-up has been modified to have the possibility
to vary the position of the crate in order to simulate the various typologies of services
First assembly tests have started
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia15
Commissioning Fase 2 Tile – integrazione dei servizi
Commissioning Fase 2 Tile – integrazione dei servizi
Phase 2 will start when moving to interaction point z=0 → 26 Ottobre 2005.
Final Cabling to be completed to connect to USA15 2 Barrel partitions commissiong (4 ROS) central DAQ (~
5000 channels) with CIS, Laser (LED backup) – 1.4.06 Setting of EM scale: carry out complete Barrel Cesium
calibration Cosmic muon run with final DCS, DAQ, … stability
performance with calibration & cosmics Use Low level online monitoring for debugging Trigger will cover all range (<0.8) and partially in
(<1.2 top and bottom) Integration of Tile Barrels in final DAQ 5.2006
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia16
Commissiong Fase 2 Barrel LAr – integrazione dei servizi
Commissiong Fase 2 Barrel LAr – integrazione dei servizi
LArg Phase 2 Commissioning: (01/01/06-01/03/06) Should demonstrate stable data taking condition Integration in DAQ and DCS Check electronics beyond Phase 1 tests, noise over
whole calorimeter (and replace electronics if needed) Start barrel cool down
HV DCS is under Milano responsibility: In this phase DCS will play a crucial role in controlling
the system The goal is to provide by that time integration of the
system with the rest of the DCS, Alarm handling and output in the Condition Database (PVSS → COOL DataBase)
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia17
Commissiongin phase 2 LAr - operationCommissiongin phase 2 LAr - operation
Cold Calibration: (01/03/06-01/05/06) • fully qualify the electronics performances: stability
measurement over long period (FEC temperature), tuning of parameters (timing, …),
• Take calibration data to demonstrate performances (noise, electronics). Produce calibration (ramps, Optimal Filtering) to fill databases with best calibration gains and Optimal Filtering coefficients
• Milano will produce Optimal Filtering Coefficients using the RTM (“Milano”) method. Now working on the SW infrastructures to handle in Athena and in the DB all the calorimeter modules
• Set High Voltage ON
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia18
Commissiong Fase 2 – integrazione LAr & Tile Commissiong Fase 2 – integrazione LAr & Tile
Setup of LVL1 implemented with TileCal triggering signal - timing, readout sync. Trigger will cover all <0.8 <1.2 (top and bottom) . Rates measured by Tiles in June with 1/6 of trigger modules: ~1 Hz (single tower), few mHz (back to back) Combined cosmic run start: 1.6.06 LArg Test beam muons: S/N~7
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia19
Other ongoing activities – Pisa group Other ongoing activities – Pisa group • Laboratory test on PMTs and fibers at the Pisa laboratory :
Characterization of PMT aging @ 1-2 LHC years full luminosity
Study of light losses in bended fibers
• Physics analysis:– Higgs channels produced in VBF with H decay to b or tau’s,
Z+jet → bb jet, Single top production (with Trieste).
• CTB analysis. Single pion study comparison with G4 for E [20,300] GeV. Recently started study on low energy data E [1,10] GeV
• Jet Calibration at hadronic energy scale
• Tile Muon identification and tagging
• GNAM Online monitoring and OHP presenter
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia20
Other ongoing activites - MilanoOther ongoing activites - Milano
EM Calibration: – Study of a calibration scheme based on Geant 4– Achieve good resolution and linearity at the same time– Ongoing work (MC: no noise, single particle from z=0 at one h position):
• Fit calibration coefficients• Study energy and dependence• Study particle dependence (electron, photon)
Study of the channel H→:– Evaluate ATLAS performance on this channel– Test calorimeter performance, test EM calibration scheme
Study of Z lep+had+’s– Control sample for reconstruction of t’s and for calibration of ET
miss during commissioning: s(MZ) s(ET
miss)– Study finalized to the analysis of the H/A MSMM decay– Expected ~2000 events in mass bin (66-116 GeV ) ~5% (+/-5%) from
main background (W+jets ) for an integrated luminosity of 10 fb-1
– Next: Tune cuts, add other backgrounds (bb, tt)
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia21
Position of Pisa and Milano in ATLAS organization
Position of Pisa and Milano in ATLAS organization
Responsabilities for Pisa
Tile DAQ-tools (commissioning)
Tile Online Monitor
Tile G4 Simulation of Real Detector
Tile Physics Data Quality
Co-cordinator of JetETmiss group
Chair of Tile Institute Board
Responsabilities for Milano
Co-coordinator JetEtMiss and tau groups
LAr electronic coordinator
Responsabile ATLAS Italia
Member of LArg representative group and member of BarrelPhase3Commissioning and EndCapPhase3Commisiong steering group
• In RED we ask for integration of ME
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia22
Milestones Tile 2005Milestones Tile 200531/03/05 –
– Codifica algoritmi per il timing con impulsi laser OK– Implementazione del monitor on-line per test in UX15 OK
30/04/05 –– Studio identificazione globale dei mu (recupero perdita di energia ed
isolamento) OK
31/05/05 - identificazione dei mu di basso pt al LVL2 nel framework HLT OK
30/06/05 -Tests temporizzazione sul Barrel in UX15 solo con cosmici
31/10/05 - Completamento cablaggio Barrel (a Z=0) delayed Jan 2006
30/11/05 - – Integrazione del monitor nella DAQ provvisoria (MobiDAQ) per run di cosmici
OK – Implementazione degli algoritmi nella ricostruzione combinata dei mu (Offline
in ATHENA) OK – Temporizzazione del barrel con impulsi laser delayed Jan 2006
31/12/05 - Inizio installazione EBC in UX15
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia23
Milestones 2005 LAr Milestones 2005 LAr
31/08/05– Installazione SW e inizio tests HV in USA15 OK
31/08/05– Inizio misure HV sul Barrel a z=0 delayed to Nov/Dec– Completamento misure HV finished on 25.9 – TDR di ECA (in B180) finished on 18.9 – Analisi dei dati del test beam in via di finalizzazione
OK
31/10/05– Inizio integrazione dei servizi su EC-C in UX15
delayed to Jan 2006
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia24
Milestones LAr & Tile 2006 Milestones LAr & Tile 2006 31/03/06 LArg Delay runs, master waveforms per calcolo OFC nel DB del calorimetro e.m. barrelAprile/06 Tile Completamento Assemblaggio Tile EBA in UX15 31/05/06 LArg Completamento installazione dei servizi su LArg ECC e ECAGiugno 06 LArg + Tile Cosmic Run with Tile and LArg31/10/06 LArg Implementazione SW del controllo HV su tutto il LArg nello standard DCS di ATLAS Dicembre /06 Tile Commissioning Tile EBC e EBAGennaio/07 LArg + Tile Cosmic ray run su Tilecal+LArg Endcap
Le date delle milestone sono indicative, spostate di due mesi rispetto a quelle previste per il ritardo di 7 settimana dovuto al ritardo nello spostamento a z=0. Il nuovo programma con le date precise e` in via di definizione.
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia26
HV systemHV system
Software status:Iseg SW (OPC server)
– Good progress: V4.0 under use now pretty stable
Milano is responsible of the HV control SW (OPC client)
– Program used for barrel, ECC cold tests and test beams
– Current version under use now for the ECA cold test
Now working on the integration with the rest of the DCS system
– ATLAS DCS hierarchical system, FSM (Finite State Machine)
– FSM: main tool for the implementation of the full control hierarchy in ATLAS, handle the states and transitions of the different parts of the detector.
– In near future this activity will need increasing interaction with DCS at CERN
First prototype available for EMEC
Hardware status:Task force (three Milano people involved) to investigate past Iseg module failures still in actionNew repaired (optocoupler exchanged) modules under test8 modules (256 channels) under test on Milano load boxes (1.5 F and 150 k per chan) at max voltage since 7/7:
– 1 single channel failure (regulation problem)
51 modules in use for ECA cold test at nominal voltage:
– 1 single channel failure
Endurance test will continue at least up to 25/9
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia27
Group composition PisaGroup composition Pisa
Paolo Adragna (Dott) 100.
Vincenzo Cavasinni (PO) 80.
Tarcisio Del Prete (INFN) 100.
Andrea Dotti (Dott) 100.
Vincenzo Flaminio (PO) 20.
Francesca Sarri (Dott) 100.
Anna Lupi (Ass) 100.
Chiara Roda (RU) 80.
Giulio Usai (Ass) 100.
Iacopo Vivarelli (Ass) 100.
FE 8.8
Neolaureati 1 livello: Paolo Francavilla
Laureandi (spec.): M. Canneri, P. Francavilla, M. Cascella
Neo-Dottorato: Iacopo Vivarelli
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia28
Composizione del Gruppo MilanoComposizione del Gruppo MilanoRicercatori :
– D. Banfi (Dottorando, 100%)
– L. Carminati (Ass. Uni., 100%)
– D. Cavalli (Dir. Ric., 100%)
– G. Costa (Dir. Ric., 100%)
– M. Delmastro (CERN Fellow, 25%)
– M. Fanti (Ric. Uni., 100%)
– L. Mandelli (PO, 100%)
– M. Mazzanti (1° Ric., 100%)
– L. Perini (PA, 100%)
– F. Tartarelli (Ric., 100%)
Tecnologi:
– M. Citterio (1° Tec., 45%)
– S. Coelli (art. 23., 10%)
Tot: 10 fisici, 2 tecnol. (9,80 PE)
Laureandi:
– C. Paleari
Tecnici:
– G.Braga (100%), B.Monticelli (100%), F.Alberti (60%)
Coordinatrice WG Jet, e PTmiss Perf.
Membro LAr repres group; Membro BP3C e ECP3C steering groups
Responsabile ATLAS Italia
LAr electronic coordinator
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia29
EM Signal Reconstruction - CBTEM Signal Reconstruction - CBTOptimal Filtering Coefficents (Milano Method) ready for all EMB cells (all samplings) in database
– Default method for test-beam reconstruction in the offline
– Used by most of the on-going analysis in the Collaboration
LAr Optimal filtering coefficients standalone results are already comparable to previous testbeam for resolution and uniformity
– Uniformity measured on a smaller number of cells
2006 activity:– Prepare infrastructures and get
ready for cosmic ray run
Ene
rgy
(GeV
)
rms0.62%
0.45%
4.5‰0.49%
P13 module
P13 module > 7
P15 module > 7
preliminary
RMS<E> = 0.36%
Ebeam=245 GeV
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia30
Towards Data Taking Towards Data Taking
After the barrel cryostat has been cooled down, filled, sub-cooled and stabilized:– Checking LC at cold (1/2 crate)
• Some FEBs removed, need to be re-tested afterwards
– Ramp up HV (procedure used in B180 barrel), decide on HV sparking of some channels• Take care not to damage calibration resistors, re-measure Rcal after treatment• Some FEBs need to be removed, need to be re-tested afterwards
– Calibration runs at cold – compare with measurements from B180 and at warm
In February and beg. of March 1 week of solenoid mapping with the solenoid field on
– We consider some coherent noise measurements (pedestal runs)
Set-up trigger from tiles Rough timing adjustment between our detector and the LVL1 acceptAfter TDAQ integration with tiles check synchronisation with Tiles read-outDCS, interlocks installed and working
– Especially FEB temperatures of great importance
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia31
EM Energy reconstructionEM Energy reconstruction
Calibration scheme based on Geant 4 Montecarlo:– Calibration hits: energy lost in dead materials (upstream, downstream,
absorbers)– Also tested with test beam data 10-250 GeV
Achieve good resolution and linearity at the same timeOngoing work (no noise, single particle from z=0):
– Fit calibration coefficients– Study energy and dependence– Study particle dependence (electron, photon)
In future apply to H→analysis and evaluate performanceEM calibration activity (and H→performance studies) will
continue also in 2006
impactcellleaki
visi
sampl
visvisPS
visPS
rec fdepthfEf
EdEEEcEEbEaE 3,11 )(1
)()()()(
Energy lost upstreamof PS (cryo,…)
Energy lost betweenPS and calo
Inverse sampling fractionand lateral leakage
Longitudinalleakage
modulations
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia32
Parameter extraction Parameter extraction
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia33
Parameter extraction & resultsParameter extraction & results
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia34
Energy reconstructionEnergy reconstruction
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia35
ETmiss, reconstructionETmiss, reconstruction
Study of Z lep+had+s
Control sample for reconstruction of ’s and for calibration of ET
miss during commissioning:
(MZ) (ETmiss)
~ 40 k evts (Rome data)– Digitized with noise in calorimeter– Analysed from AOD and CBNT ROOT
ntuple
ETmiss reconstructed
from all calo cells in ||<5 with |Ecell|>2(noise) (H1-style weights)
or from cells in topoclusters (H1-style weights)
Muons contribution (muons reconstructed in spectrometer) Cryostat correction
Next:– Tune cuts– backgrounds (also bb,tt)
pt(jet) > 30 GeV, ||<2.5pt(lep) > 16 GeV, ||<2.5
1.8< < 2.7 or 3.6< <4.5 mT(lept-pTmiss)<25 GeVpTmiss>18 GeV
-likelihood > 8 (-eff ~ 30%)
No lepton isolation
Applied TDR cuts : No retuning
Expected ~ 2000 evts in mass bin (66-116 GeV ) ~ 5% (+/-5% !!) from main background (W+jets ) for an integrated luminosity of 10 fb -1
invariant mass for Signal and Background
<> ~ 91.8 ~ 13.9
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia36
Now in the pitNow in the pit
Ready to roll inside the toroids into the final position...
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia37
Status of BARREL commissioning (now!)
• Mechanics:
• installation OK, • movement of barrel tested OK,• geometry within envelope.
• Electronics:
• Drawers: some failures (10%), after burning; being fixed• LV PS: still on critical path but the first 20 units being delivered
this week• HV, work in progress, still some problem of stability (readout?).• RODs: units are almost ready, programming still in progress
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia38
Tests in Pisa: PMT long run tests (G. Usai, F.Sarri)
Test of stability of PMT operating in LHC
environement for 1-2 years at full luminosity.
We badly need air conditioning
system to have a stable and reliable
system
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia39
On the fiber setup we did not do much... And gave priority to PMT tests.
We recovered the old setup and checked results.
The Fic didn’t boot. Discovered a weared off backup battery... Which is out of production... After few months got a replace.
A VME crate started giving problems...
We planned some changes in the setup:– Modify the shutter and the light splitter
– Use different light source (more intense and pulsed). The pulsed light should improve on the stability
– Re-write the DAQ
To carry on the tests we need:– New light source, the same as needed for PMT tests
– A more modern DAQ
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia40
Physics analysis.Two analyis to check the possible use of a LVL2 “b-tagger” (FASTRACK a la CDF or battery of CPUs).
•pp->j+Z+X with Z->bb (b-tagged jets); if possible to trigger on this channel it would be the ideal way of calibrating the b-jets.
•pp->bb+A/H with A/H->bb (3/4 b-tagged Jets); this is a standard discovery channel of the supersymmetric Higgs.
In both studies the b is assumed to decay hadronically and be identified by impact parameter.
The advantage is the BR, the disadvantage is the tag efficiency, mistags.
•pp->Hqq +X with H->
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia41
Back
Energy in a cone around a tagged muon (G. Usai)
Cone radius
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia42
• Mean value for CIS signal as PMT function• Distribution (48 PMTs) of mean value for CIS signal• Distribution (48 PMTs) of rms for CIS signal• Signal Timing as PMT function (no corrections applied)
1
2
3
4
BackBack
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia43
Energy distribution Ebeam = 180 GeVEnergy distribution Ebeam = 180 GeV
180 GeV =0.35
LArg
TileCal
LArg + TileCal
E (MeV)
E (MeV)
E (MeV)
Ent
ries
(A
.U.)
Ent
ries
(A
.U.)
Ent
ries
(A
.U.)
Back
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia44
Mean reconstructed energyMean reconstructed energy
3%
Back
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia45
20 Gev 50 Gev
100 Gev 200 Gev
Using weighting techniques on CTB data (Chiara, Iacopo, Andrea)
i
iiii E
baEw )(
The energy of cell i is weighted:
a, b are obtained by minimizing:
e beam
beamii
E
EEw2
Linearity Resolution
RawCorrected
Back
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia46
This activity comes along with the Jet Energy reconstruction/calibration (Chiara, Iacopo).
Calibration of DC1 dijet (QCD) sample has been done, in progress the work on the “Rome-layout” production.
Few methods of jets reconstruction (cone, kt, topojet) and then recalibration.
Results of our method: linearity +-2% (0.02-4 TeV) resolution improves by 15%
The package is now one of the standard method in Athena.
Chiara is becoming the convener of the jet reconstruction and calibration for ATLAS group
Back
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia47
Signal QCD
LVL1 Rate
KHz
- 4.9
LVL2 Rate
Hz
- 98-10
Kin. Sel+2b
fb
1098 195000
80<Mbb<100
fb
551 21100
Jet+Z->bb (V. Cavasinni and I. Vivarelli)
S/B S/√B
30 fb-1
2.5% 20.6
Needs to lower the jet thresholds to have sidebands for bknd subtraction, hence reduce the rates at LVL2 by fast tagging b-quarks.
Back
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia48
pp-> bb+A/H->4b (3/4 tagged) (V. Cavasinni and I. Vivarelli)
Selection εS εB S
(30 fb-1)
B
(30 fb-1)
S/B S/√B
Official ATLAS HLT menu
0.11% 1.6 10-9 140 4630 3.0% 2.0
Improved multijet trigger
1.1% 1.3 10-8 1380 36850 3.7% 7.2
The proposed trigger allows to have a factor 10 more statistics.
To avoid too large QCD rate it needs fast b-tagging.
It is a counting experiment where the new scheme of triggering can improve the significance over the standard trigger menu.
Back
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia49
ATLAS light HIGGS discovery potential at 30 fb-1
• Vector boson fusion qqHat least one decaying leptonically) fundamental at masses 120-140 GeV.
Back
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia50
HVBF hhF.Sarri, V. Cavasinni, I.Vivarelli)
In this channel, comparing to the one with at least one tau leptonic decay, we have an additional
huge background from QCD:
fbhhBRHBRVBFsig 125)()(
11103.1)10(
GeVpTQCD
sig
The algorithm to identify ’s and reject QCD jets is the fundamental ingredient.
Use the results of the Milano,Freiburg groups: D. Cavalli, M. Heldmann
Back
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia51
“Soft” cuts: essentially lower pt thresholds
HVBF hh signal vs QCD backgroundpreliminary
Back
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia52
Analysis of VLE data
In the 2004 CTB we had a period of low energy beams (E=2-9 Gev)
• Important to check Calorimeter system performance at low energy:
• a Jet is made of low energy particles• Check recalibration methods at these energies
• A good exercise to exploit a complete ATLAS slice
Set upBack
Napoli, 21 Settembre 2005 C.Roda per Lar & Tile ATLAS Italia53
Analysis of VLE data (2)
Data are not easy to analyse:• Pions and electrons,• HE muons (primary beam),• LE Decay muons.
To remove HE muons and identify e, we need to exploit all the ATLAS slice: TRT for electrons, MDT and D-cell of Tile for HE muons.
e
The work has just started
Back