1. Generation of Radiative B-Decays Decay Channels Bs  Phi + Gamma Bd  K * + Gamma Gareth Brown, RAL PPD5/10/06 Thanks to, Bill, John, Monica and Julie K at RAL, and also J.Catmore and M.Smizanska for their help

2. Decay Channels Bs  Phi +Gamma PT cut on gamma of 4GeV PT cut on muon of 6GeV Phi  K + + K - Bd  K* + Gamma PT cut on gamma of 4GeV PT cut on muon of 6GeV K*  K + + pi -

3. Generation Process 1. Set up to run Pythia B 2. cmt co Generators/PythiaB 3. Edit files uf_Bsphigamma.F, PythiaB.cxx, and user_finsel.F from src/ 4. Recompile the code 5. Edit the Signal file (.py) 6. Run using Job Transforms on either Lxplus or Grid.

4. Setting up for Pythia B Zsh Mkdir workdir cd workdir # create a requiremenst file that uses this workdir set CMTSITE CERN set SITEROOT /afs/cern.ch macro ATLAS_DIST_AREA ${SITEROOT}/atlas/software/dist macro ATLAS_TEST_AREA workdir use AtlasLogin AtlasLogin-* $(ATLAS_DIST_AREA) # set up the environment source /afs/cern.ch/sw/contrib/CMT/v1r18p20060301/mgr/setup.sh cmt config mkdir -p AtlasOffline-12.0.0/run source setup.sh -tag=12.0.0,opt source /afs/cern.ch/atlas/software/builds/AtlasOffline/12.0.0/AtlasOfflineRunTime/cmt/setup.sh cd AtlasOffline-12.0.0/run source /afs/cern.ch/atlas/software/releases/AtlasSimulation/2.0.0/AtlasSimulationRunTime/cmt/setup.sh cp /afs/cern.ch/atlas/software/releases/AtlasSimulation/2.0.0/Generators/PythiaB/share/*. get_files PDGTABLE get_files PDGTABLE.MeV athena PythiaB_Signal.py > log.txt

5. Editing files In Generators/PythiaB/src/ uf_Bsphigamma.F if(name_selv(I).eq.22.and. + name_father(I).eq.531.) then PT = SQRT(P(I,1)**2+P(I,2)**2) TH = ACOS(P(I,3)/SQRT(PT**2+P(I,3)**2)) ETA = -LOG(MAX(.0001,ABS(TAN(.5*TH)))) print *,'Ptgamma: ',PT,' eta: ',ETA if(PT.gt.4.and.abs(ETA).lt.2.5) then iret2=0. print *,'After cut Ptgamma: ',PT,' eta: ',ETA endif

6. PythiaB.cxx else if ( m_forceDecayChannel == "Bsphigamma" ) { idc = 6; } user_finsel.F c 6: Bsphigamma (RAL) if ( iufdc.eq. 6) call uf_Bsphigamma(iret)

7. Recompiling the code in../cmt “cmt config” “gmake” Edit the Signal file (.py) PythiaB.PythiaCommand += ["pydat3 mdme 977 1 1", "pydat3 kfdp 977 1 333", "pydat3 kfdp 977 2 22" ] PythiaB.ForceDecayChannel = "Bsphigamma"

8. Generated Events Pt Distribution of gamma with a 4GeV cut

9. Data Sets Generated data sets are: /castor/cern.ch/user/s/scottw/gjab02/csc.018201.Bs_phi_Kplus_Kminus_gamma4.evgen._00001.pool.root /castor/cern.ch/user/s/scottw/gjab02/csc.018201.Bs_phi_Kplus_Kminus_gamma4.evgen._00002.pool.root /castor/cern.ch/user/s/scottw/gjab02/csc.018201.Bs_phi_Kplus_Kminus_gamma4.evgen._00003.pool.root /castor/cern.ch/user/s/scottw/gjab02/csc.018201.Bs_phi_Kplus_Kminus_gamma4.evgen._00004.pool.root /castor/cern.ch/user/s/scottw/gjab02/csc.018201.Bs_phi_Kplus_Kminus_gamma4.evgen._00005.pool.root /castor/cern.ch/user/s/scottw/gjab02/csc.018201.Bs_phi_Kplus_Kminus_gamma4.evgen._00006.pool.root /castor/cern.ch/user/s/scottw/gjab02/csc.018201.Bs_phi_Kplus_Kminus_gamma4.evgen._00007.pool.root /castor/cern.ch/user/s/scottw/gjab02/csc.018201.Bs_phi_Kplus_Kminus_gamma4.evgen._00008.pool.root /castor/cern.ch/user/s/scottw/gjab02/csc.018201.Bs_phi_Kplus_Kminus_gamma4.evgen._00009.pool.root /castor/cern.ch/user/s/scottw/gjab02/csc.018201.Bs_phi_Kplus_Kminus_gamma4.evgen._00010.pool.root

10. Graphs showing the eta and phi difference between the daughter particles and the >4GeV Gamma

11. Graph showing the eta difference between daughter particles and gamma against the phi difference between daughter particles and gamma

12. Graph showing the eta difference between daughter particles and gamma against the eta difference between daughter particles and muon

13. Graph showing the eta difference between daughter particles and muon against the phi difference between daughter particles and muon

14. Graph showing the phi difference between daughter particles and gamma against the phi difference between daughter particles and muon

15. Summary We can now generate any B-decay channel, adding cuts on kinematics quantities etc. Currently Super symmetry isn’t involved in the generation process, and will need to be added. We have generated10,000 events that are currently available in Castor, but still need to be simulated, digitized and reconstructed.