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Graviton production and decay in warped extra dimensions. V. Vassilakopoulos for the Hampton University ATLAS Group North American ATLAS Physics Workshop, Tucson, AZ, Dec 19-21, 2004. Objectives.
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Graviton production and decay in warped extra dimensions V. Vassilakopoulos for the Hampton University ATLAS Group North American ATLAS Physics Workshop, Tucson, AZ, Dec 19-21, 2004 1st North American Atlas Physics Workshop
Objectives Perform the full simulation in ATLAS of graviton production and decay in warped extra dimensions according to Randall & Sundrum model:Phys. Rev. Lett. 83, 3370 (1999) g+gG* l+l- or g+g G* Z0 Z0 f+fG* l+l- or f+f G* Z0 Z0 Using implemented branching ratios as in Pythia v6.221 Do analysis using Physics Analysis Tools. 1st North American Atlas Physics Workshop
Signal Issues Signal handles • Expect a narrow resonance (TeV scale) Maybe an isolated one… • Angular distribution for spin-2 particles • A displaced vertex ; it should suppress the background. Will not discuss on this talk. • Decay to SM particles. 1st North American Atlas Physics Workshop
Simulation Environment • Using Release 9.0.2 • Events generated with Pythia v6.221 • Graviton mass set to 1 TeV (pythia def.) • Checkout packages: • SimulationOptionsRome • Digitization-00-06-05 • AnalysisExamples-00-08-05 • RecExCommon-00-02-87 1st North American Atlas Physics Workshop
Full Simulation Flow • Event generation (evgen.root) • G4 simulation (g4sim.root) • Digitization (digit.root) • ESD creation from RDO (ESD.root) • AOD creation from ESD (AOD.root) • Root tree and Histos from AOD (Gee.hist.root, Gee.ntuple, etc.) 1st North American Atlas Physics Workshop
Event Generation (1) For G*e+e- Pythia.PythiaCommand += [ "pysubs msel 0", #sub processes must be explicitly switched on "pysubs msub 391 1", #graviton production ffbar, ggbar G* "pysubs msub 392 1", # acc to Randall-Sundrum model. "pysdat3 mdcy 347 1 1", # Graviton decays "pydat3 mdme 4158 1 0", #all graviton decay modes turned off but… … "pydat3 mdme 4166 1 1", # … the decay G*e+e- … "pydat3 mdme 4177 1 0" ] 1st North American Atlas Physics Workshop
Event Generation (2) For G*Z0Z0 e+e-m+m-or e+e- e+e-orm+m-m+m- Pythia.PythiaCommand += [ "pysubs msel 0", #sub processes must be explicitly switched on "pysubs msub 391 1", #graviton production ggbar, ffbar G* "pysubs msub 392 1", #acc to Randall-Sundrum model. "pydat3 mdme 4158 1 0", # all graviton decay modes turned off but… … "pydat3 mdme 4176 1 1", # … the decay G* Z0Z0 "pydat3 mdme 4177 1 0" ] 1st North American Atlas Physics Workshop
Event Generation (3) And then enable the Z0e+e- and Z0 m+m Pythia.PythiaCommand += [ "pydat3 mdcy 23 1 1", # Z0 decays "pydat3 mdme 174 1 0", #all Z0 decay modes turned off but .. "pydat3 mdme 182 1 1", # .. Z0 ee "pydat3 mdme 184 1 1", # and Z0 mm … "pydat3 mdme 189 1 0"] 1st North American Atlas Physics Workshop
G4 Simulation • Get the files (from SimulationOptionsRome) • RomeSimulationConfig.py (edit for input & output data file, events, DetDescrVersion) • RomeGeo2G4.py • RomeEnvelopes.mac, RomeEnvelopes.xml, RomeEtaPhiFilter.mac, RomeGeometry.mac, PDGTABLE.MeV • Additional lines added in job options for DB access: RDBAccessSvc = Service( "RDBAccessSvc" ) RDBAccessSvc.HostName = "pdb01“ 1st North American Atlas Physics Workshop
Digitization, ESD • Get files DigitizationConfig.py (edit for input & output data files, events, DetDescrVersion) AtlasDigitization.py • ESD production All misconfigurations in event generation, G4 simulation or digitization will result to a fatal crash here. In addition, problems have been observed with Release during last week. Many obscure explanations circulating in atlas-sw-dev list. 1st North American Atlas Physics Workshop
AOD and Analysis • To look the produced events we modified the very similar examples in the AnalysisExamples of Zll (for Gee) and H4l (for G ZZ 4l). Working to further customize the code to extract more detailed track information. • One of our objectives is to use the convienient Physics Analysis Tools. 1st North American Atlas Physics Workshop
Required Resources About 25 MB required for input data cards & job files. 1st North American Atlas Physics Workshop
A Bumpy Road…(1) • Successfully ran interactively at BNL; the number of events is limited. • Running in LSF batch is full of problems: • DB servers too busy => timeouts • There are continuous patches, modifications in the … released software. • Reaching CPU limitations even in the 1 week(?) queue at CERN for 100 evts! 1st North American Atlas Physics Workshop
A Bumpy Road…(2) And last but not least: • Corrupted(?) pool files produced when Nevt>24 ! “Error Severe problem while closing Database. Caught in infinite loop! - ABORT CLOSE.” (see POOL/POOL_1_3_1/src/StorageSvc/src/DbDatabaseObj.cpp) In BNL getting occasional errors “NFS stale file handle” Futile to move to a large scale production now. Need to wait until coming to a ‘stable’ Release ! 1st North American Atlas Physics Workshop
Initial Data Sample • One year of running (assume L= 1033cm-2s-1) yields ~ 100 events (s~ 10-14 from pythia) • Full simulation chain with Rome (initial) conditions • 100 evts of G*e+e- • 120 evts of G*Z0Z0 e+e- e+e- • Standard cuts were used: |h|<2.5 , Ptelec> 20 GeV, etc. 1st North American Atlas Physics Workshop
Reconstructed MassGee 1st North American Atlas Physics Workshop
Reconstructed MassGZZ 4e 1st North American Atlas Physics Workshop
Reconstructed Mass of Z0 1st North American Atlas Physics Workshop
Some Track quantities 1st North American Atlas Physics Workshop
Summary • Successfully fully simulated in ATLAS graviton decay events. • Fill ESDs, AODs start doing analysis using Physics Analysis Tools. • Start planning for Rome Physics workshop… 1st North American Atlas Physics Workshop
Columbia-Nevis Group • Dominik Dannheim dannheim@nevis.columbia.edu • Kamal Benslama benslama@nevis.columbia.edu • John Parsons parsons@nevis.columbia.edu http://www.nevis.columbia.edu/~dannheim/tucson/nevis_graviton_tucson_dec_2004.ppt 1st North American Atlas Physics Workshop
Columbia - Nevis RS graviton in full simulation gg G* e+e-, mG*=500 GeV, generated with PYTHIA including QED-FSR 860 events processed in full simulation, DC 2 layout, software release 9.0.2 Default reconstruction options, no further cuts Analysis on AODs Invariant mass distribution Angular distribution in e+e- CMS Mass resolution ~3x worse than in ATLFAST • Further studies needed to understand the cause of this 1st North American Atlas Physics Workshop
500 GeV G* e+e- in ATLANTIS event display 1st North American Atlas Physics Workshop
Plans for Rome Fully simulate more graviton decay events to study the kinematics and acceptances. Explore discovery potential for lower graviton masses. Modify standard cuts and apply additional cuts if necessary. 1st North American Atlas Physics Workshop
Rome Plans (2) Include background High mass SUSY, other exotics Understand calibrations, resolutions Explore the effect of pileup and how it will affect the background. Explore Graviton decays to other SM particles (specifically muons) Expect to proceed to full simulation production in January using GRID. 1st North American Atlas Physics Workshop
END 1st North American Atlas Physics Workshop
Gravitons in warped extra dimensions • Predictions for . . . • Dark energy • Higgless mass generation • Dark matter • Hierarchy problem • . . . 1st North American Atlas Physics Workshop
Graviton Decay Width Total decay width for each KK mode G~3*10-5*N*(k/M)3(mn/L)8(Dm) Lifetime, t of each KK mode: G-1~104*(M/k)3(L8/Dm9) Dm is the mass gap between KK modes. Chang and Yamaguchi, hep-ph/9909523(1999) Randall and Sundrum, Phy. Rev. Let. 83, 3370 (1999) 1st North American Atlas Physics Workshop
Dark Energy Signatures in ATLAS Looking for displaced vertex in TRT (R>56 cm) When rc has some intermediate value • Dm may get finite value • KK mode lifetime may be ~ fraction of second When Dm ~ 10-3 eV • get displaced vertex ~ 1 meter • correct scale to describe recently discovered dark energy 1st North American Atlas Physics Workshop
Angular Distribution Spin-2 particles 1st North American Atlas Physics Workshop