Alain Romeyer - 04/06/2004 1

Alain Romeyer

2000 – 2003 : PhD Thesis on ANTARES (CEA Saclay DAPNIA/SPP)

Determination of the ANTARES diffuse neutrino flux sensitivity

2004 : Postdoc on CMS in the Mons-Hainaut university

Two activities : Computer farm installation dedicated to CMS

Final goal : included in the CMS grid structure

Study one particular SuperSYmmetric channel

Alain Romeyer - 04/06/2004 2

ANTARES

č

43°

Time, position, amplitude of the PM signals trajectory

Muons are detectedthrough their Cherenkov

light emissionp

AtmosphereSea

p,

TARGETshield

2400 m deep

• Background rejectionatm. µ discriminant variables atm. energy estimator

• Comparative study of diffuse neutrino flux models

ANALYSIS

Alain Romeyer - 04/06/2004 3

ANTARES Sensitivity

Optimal

Alain Romeyer - 04/06/2004 4

PhD Conclusion

ANTARES

km3

Alain Romeyer - 04/06/2004 5

CMS farm installation

Final goal : included in the GRID CMS framework To be involved in the CMS data processing scheme Run our own simulations and programs Develop easily and faster our analysis

Implications : install the CMS simulation and reconstruction software Make them available on all the computer of the farm

-> NFS Distribute the jobs in a “clever” way -> CONDOR Store the produced events -> RAID system disk space Connection to the GRID -> Globus

DONE

Alain Romeyer - 04/06/2004 6

Physic analysis

Preliminary studied in 1997 with fast simulation

Several benchmark MSUGRA points studied Signal can be rapidly extracted (less than 1 yr) Main bkg : SUSY combinatorial (S/B ~ 1)

h0

116 GeV

b86 %

72%

02χ

b

01χ LSP

missing energy

« B tagging »

q / g

CMS note 1997-7

0

MSUGRA (SM + 5 params)Benchmark point (Tan = 10; A0 = 0; µ > 0; M1/2 = 360 GeV; M0 = 230 GeV)

Alain Romeyer - 04/06/2004 7

Status and outlook Event production :

Pile-up events (10 000 evts - ~ 1 min/evt) SUSY events (10 000 evts - ~ 6 min/evt)

Mix pileup and SUSY events + digitisation (detector response)

(10 000 evts - ~ 25 s / evt)

Start to play with the event selection and reconstruction Trigger (HLT) -> efficiency…

Jet reconstruction (Iterative cone algorithm…) Missing Energy

B tagging