1

Attivita’ su analisi dati cosmici(“CRAFT”: B=3.8 T & CRUZET(B=0)

Pd meeting, 10 Nov 2008

A.Branca, A.Calderon, A.Gresele, U.Gasparini, A.Meneguzzo(+ F. Cavallo, Bologna)

- Contributo alla DT “prompt analysis”

- Studio prestazioni della ricostruzione muoni di ‘alto livello’ (tracce muoni globali, matching con Tracker, risoluzione in momento, allineamenti…)

- Misura di fisica: rapporto mu+/mu-

- TOF per HSCP (non trattata qui)

- Piani e seggerimenti per possibili ulteriori sviluppi

Attivita’ strettamentecorrelate..

Prima esperienzadi una“end-to-endanalysis”(da P5 a Phys.Lett.)in CMS…

2

Intro

statistics is not an issue…

- while doing a physics measurement (e.g. mu+/mu- ratio in cosmics, differential spectrum, TeV muons flux…) may concentrate on many different aspects of reconstruction, trigger performance, sources of systematics errors…

examples: - perform different tracks selection, with loose/tight criteria on track topology/quality - study/keep control of momentum resolution, charge identification - Test stability of results against different runs, triggers, detector data quality…

CRAFT: ~300 M triggercollected so far…

http: //malgeril.web.cern.ch/malgeril/coll_stats/collcosm.html

3

Prompt DT analysis http: //cmsdoc.cern.ch/cms/MUON/dt/sx5/

DT detectorperformanceoverview

More detailedinfo by wheels

[ DPG joint effort…]

4

Example of DT-DQM certified good run

DT local trigger efficiencygood DT calibration,

Run 67838

Missing DDU-trigger data in Wheel+1; data availableanyway from trigger DCC

5

DT local reco: reco segments

Run 67838, B=3.8 T12,7 M triggers

12,35 M “good” segments in MB1(Nhit(rf)>5 & Nhit(rz)=3 or 4)

6

Muon reco

16,9 Millionof Tracks

7

Example of mu reco performance study:“2 legs” STA muons

Run 6783812.7 M eventsanalyzed (~ 45% of total triggers)

DT segmentmultiplicity

StandAlone muons

associatedhits to tracks

cut

4,1 M with Nlegs=2

difference inZ-impactparameter

z,both legswithNhit>30 z| < 20 cm

1,100,000STA pairs

pT/pT~36%

1st leg

2nd leg

8

Control of Mult.scattering & bending

B = 0(CRUZET4)

B = 3.8 T

?

?

(MB3)-(MB2)

(MB4)-(MB3)

(MB2)-(MB1)

(MB4)-(MB1)

9

Data vs MonteCarlo

Hit/segment/track resolution & efficiency to be x-checkedwith cosmic MontCarlo…

- “B ON” RECO production not yet available…

- First comparisons performed @ B=0 (CRUZET4 data) …

For more detail see e.g. Ambra’s talk @ muon POG, 13/10/08: http://indico.cern.ch/conferenceDisplay.py?confId=42597

10

1 leg STA tracks vs Tracker tracks

1 leg STATrack,Nhit > 60

Trackertrack

pT/pT~25%

pT/pT~22%

pT/pT~18%

11

Charge identification: 1 leg STA vs Tracker

880 out of27,700 tracks(3.2%)

12

Mu+/Mu- ratio

P.Garcia, CMS Phys.Plenary 6/11/08

http: //indico.cern.ch/conferenceDisplay.py?confId=44067

Florida,CIEMAT

Padova, Bologna

More info, today’s talk by Ambra @ Cosmic Muon Analysis meeting:http://indico.cern.ch/conferenceDisplay.py?confId=45080

[ I wish also to advertise Stefano’s talks on reco related topics @ todays’ muon POGhttp://indico.cern.ch/conferenceDisplay.py?confId=43177 ]

13

Mu+/mu- ratio: 1st look

Using“one leg” STATrackswith Nhit > 60 unphysical tail…

25,000 tracks(this correspondsto ~3% of totalCRAFT statistics)

uncorrectedfor chargemis-identification

14

Stability of result: another run ( 66783 )

15

Alignment checks (very preliminary)

Alicia

No alignment

Alignment tag inOfficial reco

16

Tools for analysis- CAF (Cern Analysis Facility) almost saturated from processing, prompt analysis…-Some long good run transferred to Legnaro-T2-See https://cmsweb.cern.ch/dbs_discovery/

66615,66783,67838

17

Tools for analysisAnalyzer code on:

/raid4/data/share/CRAFTanalysis/DAnalyzer.cc

Produced rootple on:/raid4/data/share/CRAFTanalysis/rootple

Rootples contains: - trigger info (local chamber & DTTF) - DT segment info - muon standalone 2 legs collection - muon standalone 1 leg collection - muon global 2 legs collection - muon global 1 leg collection

- Tracker tracks collection