Hampton Univ. Group1 st North American Atlas Physics Workshop 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

Hampton Univ. Group1 st 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+g  G *  l + l - or g+g  G*  Z 0 Z 0 f+f  G *  l + l - or f+f  G*  Z 0 Z 0 Using implemented branching ratios as in Pythia v6.221 Do analysis using Physics Analysis Tools.

Hampton Univ. Group1 st 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.

Hampton Univ. Group1 st North American Atlas Physics Workshop Simulation Environment Using Release Events generated with Pythia v6.221 Graviton mass set to 1 TeV (pythia def.) Checkout packages: –SimulationOptionsRome –Digitization –AnalysisExamples –RecExCommon

Hampton Univ. Group1 st 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.)

Hampton Univ. Group1 st 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 ", # Graviton decays "pydat3 mdme ", #all graviton decay modes turned off but… … "pydat3 mdme ", # … the decay G*  e + e - … "pydat3 mdme " ]

Hampton Univ. Group1 st North American Atlas Physics Workshop Event Generation (2) For G*  Z 0 Z 0  e + e -     or e + e - e + e - or         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 ", # all graviton decay modes turned off but… … "pydat3 mdme ", # … the decay G*  Z 0 Z 0 "pydat3 mdme " ]

Hampton Univ. Group1 st North American Atlas Physics Workshop Event Generation (3) And then enable the Z 0  e + e - and Z 0     Pythia.PythiaCommand += [ "pydat3 mdcy ", # Z 0 decays "pydat3 mdme ", #all Z 0 decay modes turned off but.. "pydat3 mdme ", #.. Z 0  ee "pydat3 mdme ", # and Z 0   … "pydat3 mdme "]

Hampton Univ. Group1 st 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“

Hampton Univ. Group1 st 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.

Hampton Univ. Group1 st 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 G  ee) 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.

Hampton Univ. Group1 st North American Atlas Physics Workshop Required Resources About 25 MB required for input data cards & job files. Step G  eeG  ZZ  4e evgen~ 22 kB/evt~ 23 kB/evt g4sim~830 kB/evt ~ 16 min/evt ~950 kB/evt ~ 17 min/evt digit~1.6 MB/evt ESD~ 440 kB/evt~500 kB/evt AOD~ 11 kB/evt~ 12 kB/evt

Hampton Univ. Group1 st 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!

Hampton Univ. Group1 st North American Atlas Physics Workshop A Bumpy Road…(2) And last but not least: –Corrupted(?) pool files produced when N evt >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 !

Hampton Univ. Group1 st North American Atlas Physics Workshop Initial Data Sample One year of running (assume L= cm -2 s -1 ) yields ~ 100 events (  ~ from pythia) Full simulation chain with Rome (initial) conditions –100 evts of G *  e + e - –120 evts of G *  Z 0 Z 0  e + e - e + e - Standard cuts were used: |  | 20 GeV, etc.

Hampton Univ. Group1 st North American Atlas Physics Workshop Reconstructed Mass G  ee

Hampton Univ. Group1 st North American Atlas Physics Workshop Reconstructed Mass G  ZZ  4e

Hampton Univ. Group1 st North American Atlas Physics Workshop Reconstructed Mass of Z 0

Hampton Univ. Group1 st North American Atlas Physics Workshop Some Track quantities

Hampton Univ. Group1 st 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…

Hampton Univ. Group1 st North American Atlas Physics Workshop Columbia-Nevis Group Dominik Dannheim Kamal Benslama John Parsons ton_tucson_dec_2004.ppt

Hampton Univ. Group1 st North American Atlas Physics Workshop RS graviton in full simulation Invariant mass distributionAngular distribution in e + e - CMS gg  G*  e + e -, m G* =500 GeV, generated with PYTHIA including QED-FSR 860 events processed in full simulation, DC 2 layout, software release Default reconstruction options, no further cuts Analysis on AODs Mass resolution ~3x worse than in ATLFAST  Further studies needed to understand the cause of this Columbia - Nevis

Hampton Univ. Group1 st North American Atlas Physics Workshop 500 GeV G*  e + e - in ATLANTIS event display

Hampton Univ. Group1 st 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.

Hampton Univ. Group1 st 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.

Hampton Univ. Group1 st North American Atlas Physics Workshop END

Hampton Univ. Group1 st North American Atlas Physics Workshop Gravitons in warped extra dimensions Predictions for... –Dark energy –Higgless mass generation –Dark matter –Hierarchy problem –...

Hampton Univ. Group1 st North American Atlas Physics Workshop Graviton Decay Width Total decay width for each KK mode  ~3*10 -5* N*(k/M) 3 (m n /  ) 8 (  m) Lifetime,  of each KK mode:   ~10 4* (M/k) 3 (  8 /  m 9 )  m is the mass gap between KK modes. Chang and Yamaguchi, hep-ph/ (1999) Randall and Sundrum, Phy. Rev. Let. 83, 3370 (1999)

Hampton Univ. Group1 st North American Atlas Physics Workshop Dark Energy Signatures in ATLAS Looking for displaced vertex in TRT (R>56 cm) When r c has some intermediate value  m may get finite value KK mode lifetime may be ~ fraction of second When  m ~ eV get displaced vertex ~ 1 meter correct scale to describe recently discovered dark energy

Hampton Univ. Group1 st North American Atlas Physics Workshop Angular Distribution Spin-2 particles