Kali Calo

Kali Calo

Vanya BELYAEV

mailto:[email protected]?subject=Bender%20Tutorial%20v7r0

Vanya Belyaev (Nikhef & ITEP ) 2

Iterative p0 calibration

• The “standard” procedure• HERA-B

• Robust (as soon as p0 peak is vizible)• “Millipede-like” algorithms are fragile

• Rely only on “standard” reconstruction technique• No “dedicated” reconstruction

• Can be done “track-independent”

• Requires only limited information

• Can be rather fast ( “on-line” mode)

6 Oct 2k+9


• Rely on “multiplicative” calibration• 0 ~ Eprs <<Eecal, • the best contribution from Eseed ~ Eecal

• simultaneous Ecal/Prs calibration is difficult• Needed? Sensitivity to Prs is not large

• For physics: Eprs > E0 , for calibration Eprs < E1

• Contradiction?

Eprs > E0 : small background + large statistics

Eprs < E1 : large background + small statistics

6 Oct 2k+9


Eprs

Eprs > E0 : small background + large statistics

- fast convergency to “wrong” constantsEprs < E1 : large background + small statistics

- slower convergency to “correct” constants Combine!

• Few iterations with Eprs > E0

• Then switch to Eprs < E1

• (Intermediate scenario ? ) g1: Eprs < E1

g2: Eprs > E0

6 Oct 2k+9


Data Flow for Kali-p0 (I)

6 Oct 2k+9

Kali-p0 Job

ROOT NTuple/TTreeDST or DAQ

fmDST


Data Flow for Kali-p0 (II)

6 Oct 2k+9

ROOT NTuple/TTree

•Make histos using the current estimate for calibration

constants

• Fit histograms

• Get corrections for calibration constants

Iterate up to convergency

• produce the final set of calibration constants

Set of Calibration

constrants CondDB (?)

(optional)

• 2k+(4-5): 3-5 iterations are OK

• 2k+9 : 2-3 iterations are OK


Data Flow for Kali-p0 (III)

The secondary iterations

6 Oct 2k+9

Kali-p0 Job

ROOT NTuple/TTree

fmDST

CondDB (?)

(optional)

Set of Calibration

constrants


Kali-p0 Job

• Regular Gaudi-based job• Actually “stripped-down” version of DaVinci• (optionally) apply constants to Ecal digits

• Calibrate/re-calibrate/mis-calibrate

• (re-recontruct) Calorimeter objectsClusters, Hypos, Neutral ProtoParticles, Photons

• LoKi-based algorithm that acts on LHCb::Particles• StdLooseAllPhotons• Find good p0→gg candidates with loose cuts• Fill n-tuple• (optionally) Destroy TES!

• Write femto-DST

6 Oct 2k+9


Kali-p0: fmDST

• Write only Spd/Prs/Ecal/Hcal digits that make contributions into “good” photons from “good” p0-candidates

• Write in TES-format:Raw/Ecal/DigitsRaw/Spd/DigitsRaw/Prs/DigitsRaw/Hcal/Digits

• 500k minimum bias MC09 events on input:• 380k evens with “good” p0 : 150MB of fmDST

• ~ 330 bytes/event, mainly due to Gaudi overhead• ~ 300GB for 109 available MC09 statistics

6 Oct 2k+9

“Natural” input for Kali Job

Easy to (mis)Calibrate!


Kali-p0: Calo(re-)Reco

• Defines the rules (using only the standard stuff) for Calo (re)-reconstruction

•Mainly definition of neutrality criteria: Use Tracks (only for DST of DAQ/farm input Use Spd Use both (.OR. mode) ( DST/DAQ/farm) Use None (all clusters are “neutral”)

Clearly the definition for the first pass is the most important for the subsequent

processing6 Oct 2k+9


Kali-p0: NTuple/TTree

• Very simple structure: p0 : mass, energy, ET

g1,g2 : energy, ET, Eprs, Espd, seed-cell-id

• 13 variables: more compression is possible (x2?)

• Pre-cuts (rather loose to allow the refinement): m(p0) < 250 MeV/c2,

ET(p0) > 800 MeV

• Photons are ordered according to Eprs: • Easier to apply Eprs cuts & choose the proper

photon

• 500k minimum bias events: 30 MB• 30 GB for available 109 MC09 statistics

6 Oct 2k+9

$LHCBHOME/group/calo/ecal/vol10/Pi0/KaliPi0_Tuples.root


Kali-p0: analysis utilities

• Project histograms with constants:• C++ (T)Projector-based : ../root/Kali_Pi0.C

• Not flexible enough But it works…

• Python’(TPy)Selector meets some problems

• Fit histograms: KaliCalo/Pi0HistoFit.py• fitPi0Histo:

• primitive: gaussian + 3rd order polynom • can (& should!) be improved e..g using Albert’s trick • Initial values, background shape, re-iterate, fir stability &

fit-quality: We need to fit in automatic regime 6k histograms!

• Steering: not ready yet.. • Monday afternoon: news from Dasha: steering is OK

6 Oct 2k+9

translate from calib.f and calibr.kumac Choice

Use Python & PyROOT


Kali-p0: current status

• Up to last Thursday was OK with lhcb3 nightly• CVS HEAD

• C++ Selector need to be fixed

• Python Selector to be fixed

• p0-fit to be improved

• Analysis steering from Dasha to be integrated

• But for all components we have something working! • “Ready” for full scale test with GRID

6 Oct 2k+9


Kali-p0: Few plots

6 Oct 2k+9

all

min(Eprs

) > 10 MeV

min(Eprs

)< 10 MeV,

max(Eprs

)> 10 MeV

max(Eprs

) < 10 MeV


Kali-p0 steering from Dasha

6 Oct 2k+9


Kali-p0 steering from Dasha

6 Oct 2k+9


Short-term plans:

• Run Kali-p0 (using GRID) for all available 109 events• Get the estimate of Ecal calibration

• #events?

• Run various mis-calibration scenarios on fmDST• robust?

• Refine p0 selection• Define the optimal treatment of Eprs cuts for

different steps• Define the working scenario for “off-line”

calibration• Optionally:

• refine Calo(re-)Reco settings, next slide

6 Oct 2k+9

18

Medium –term plans

• (Complete with short-term plans)

• Make estimate of CPU in ‘on-line’-like scenario• Currently totally dominated by technical overhead:

read/unpack (2000/40000)

• Find Calo(re-)Reco configuration acceptable for “on-line” settings ”UseTracks” ?• Special Kali-p0-runs for EFF

• possibly with slightly prescaled input event rate? • Is it possible to run Kali at f >> 2kHz ?• It is possible to run Kali at O(1MHz)

• New data instead of secondary iterations!!

• Ask for some Kali-p0-FEST at EFF6 Oct 2k+9 Vanya Belyaev (Nikhef & ITEP )


“Kali-p0 Reference manual”

from Gaudi.Configuration import * from Configurables import KaliPi0Conf

KaliPi0Conf(FirstPass = True , UseTracks = True ,UseSpd = False , FemtoDst = ‘output.fmDST’ )

6 Oct 2k+9

$KALICALOROOT/python/KaliCalo/KaliPi0.py

gaudirun.py KaliPi0.py DATA.py

python KaliPi0.py

./KaliPi0.py


Kali-p0: Summary

• (Some) progress in Kali(-p0) framework• Resurrect 2k+(4/5) code

• “Ready” for full-scale test with 109 events

• Few tiny (pure technical) aspects to be solved

• GRID is essential

• fmDST are very useful

My dream: on-line Kali-p0

6 Oct 2k+9

Documents

Kali Calo