Kali Calo

progress report

Dasha Savrina (ITEP/Moscow), Vanya Belyaev

Vanya Belyaev 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)

17 Feb 2k+10

Irina

Vanya Belyaev 3

• 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

17 Feb 2k+10

Vanya Belyaev 4

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

17 Feb 2k+10

Vanya Belyaev 5

Data Flow for Kali-p0 (I)

17 Feb 2k+10

Kali-p0 Job

ROOT NTuple/TTreeDST or DAQ

fmDST

Vanya Belyaev 6

Data Flow for Kali-p0 (II)

17 Feb 2k+10

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

Vanya Belyaev 7

Data Flow for Kali-p0 (III)

The secondary iterations

17 Feb 2k+10

Kali-p0 Job

ROOT NTuple/TTree

fmDST

CondDB (?)

(optional)

Set of Calibration

constrants

Vanya Belyaev 8

Current status/Progress report

• Samples has been studied:• Monte Carlo, min-bias : 1000M

• Study cuts & fit stability

• Monte Carlo. min-bias, miscalibrated: 200M• Make the real large scale excersize

• 2k+9 collisions : Reco06, Reco07• Apply simplified version to data

• Combine cells into groups

17 Feb 2k+10

Many thanks to Albert for kind help!

Vanya Belyaev 9

MC: bad fits & small statistics

17 Feb 2k+10

Small Statistics <100

p0/cell

Bad Fit

Vanya Belyaev 10

MC: bad fits & small statistics

17 Feb 2k+10

Vanya Belyaev 11

Fit quality

• Some smartness has been introduced:• For small statistics the background shape is

fixed from “per-area” histogram• For “crazy mass, width”, skip the cell from

*current iteration*, …

• Still a lot of room for improvement

17 Feb 2k+10

5953 from

6016

Vanya Belyaev 12

How to improve fit quality?

• Better background parameterization, less degrees of freedom:

• e.g. sqrt(m)*p2(Dm) instead of p3(m)

• Better initial setting from “per-area” histos

• Some constraints against “crazy” values• Skip per iteration with hope to recover for next

iteration

• Release ePrs cuts for “problematic” cells

• Smart: Use Albert’s trick with fake p0 to fix the background shape

17 Feb 2k+10

Puzzle:

200M miscalibrated events: more stable fits…

Pure technical, but important…

Vanya Belyaev 13

200M miscalibrated events

• No more news today.• Calibration coefficients are obtained for the

first iteration• For improvement & stability, the local

reprocessing of fmDST is required (“secondary iteration”)• (Can also send the uncorrected coefficients to Olivier)

• Some pure technical problem with reprocessing of fmDST • It looks like something has been changed

recently in global DaVinci configuration (packing/unpacking/…)

• Should be easy to fix ~1-2 days… 17 Feb 2k+10

Vanya Belyaev 14

2k+9 Collision Data: Kali with 12 zones

• 5799&5800

• 4.2M events

• Mass: 139.3±0.3 →135.0±0.3

• Sigma: 13.5 ±0.5 →11.2± 0.4

• 5842 & 5845

• 0.5M events

• Mass: 139.0±0.2 →135.1±0.2

• Sigma: 13.1± 0.3 →10.9± 0.3

17 Feb 2k+10

Vanya Belyaev 15

Note: p0 mass by Victor

17 Feb 2k+10

Vanya Belyaev 16

Calibration

17 Feb 2k+10

Reco06

Reco07

Vanya Belyaev 17

Instead of summary

• Kali works with MC and real data• Final check with mis-calibrated MC samples

• (fix the reprocessing)

• Kali for Reco06 and Reco07 are in agreement• Some puzzle with PT(p0)-dependence

• Stability of fits need to be improved• It must work in automated regime!• A lot of ideas how to do it

• Selection cuts *must* be reoptimizedThere is some confidence that Kali is

does the job: Ecal calibration with p0

17 Feb 2k+10

Vanya Belyaev 18

BACKUP

17 Feb 2k+10

Vanya Belyaev (Nikhef & ITEP ) 19

Cuts

• Standard Recontruction

• No Spd hit (???)

• ET(g) > 300 MeV

• EPRS < 10 MeV

• PT (p0) > 800 MeV the most discussed cut...

6 Oct 2k+9

Vanya Belyaev 20

Kali-p0: Few plots

17 Feb 2k+10

all

min(Eprs

) > 10 MeV

min(Eprs

)< 10 MeV,

max(Eprs

)> 10 MeV

max(Eprs

) < 10 MeV

Vanya Belyaev 21

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

17 Feb 2k+10

Vanya Belyaev 22

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

17 Feb 2k+10

“Natural” input for Kali Job

Easy to (mis)Calibrate!

Vanya Belyaev 23

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

17 Feb 2k+10

Vanya Belyaev 24

Calibration

17 Feb 2k+10

No preshower cut• min Eprs>10 MeV• min Eprs<10 MeV max Eprs > 10 MeV• maxEprs<10 MeV

• Upper left outer• 0.935 • 0.936 • 0.937• Upper right outer• 0.956 • 0.962 • 0.963• Upper left middle• 0.979 • 0.989 • 0.961• Upper right middle• 0.992 • 0.986 • 0.982• Upper left inner• 1.037 • 1.050 • 1.002• Upper right inner• 1.041 • 1.047 • 1.036• Lower left outer• 0.934 • 0.939 • 0.948• Lower right outer• 0.945 • 0.951 • 0.918• Lower left middle• 0.977 • 0.979 • 0.966• Lower right middle• 0.993 • 0.988 • 0.970• Lower left inner• 1.065 • 1.062 • 1.153• Lower right inner• 1.098 • 1.096 • 1.065