Study of Bc in CMSSW: status report Silvia Taroni Sandra Malvezzi Daniele Pedrini INFN Milano-Bicocca

Silvia Taroni - INFN Milano-Bicocca Bc @ CMS (CMSSW)‏ The feasibility of Bc physics in CMS has been already studied using ORCA. CMS TDR, Vol II, page 191-195 CMS NOTE-2006/118 CMS CR-2007/078 The Bc production is ~10-3 wrt the B production. In PHYTIA the production rate of Bc is 10-6. It is necessary to enhance the event generating efficiency A dedicated generator is valuable. BCVEGPY (Comput.Phys.Commun. 174 (2006) 241-251). 17th June 2008 Silvia Taroni - INFN Milano-Bicocca

Silvia Taroni - INFN Milano-Bicocca Working with Bc In CMSSW BCVEGPY was not implemented. Since the 20th May meeting on (http://indico.cern.ch/conferenceDisplay.py?conf Id=33720), when we expressed our interest in Bc Physics, we have worked in implementing BCVEGPY in CMSSW. The generator code (Fortran) is available at the author's site: http://www.itp.ac.cn/~zhangzx 17th June 2008 Silvia Taroni - INFN Milano-Bicocca

Silvia Taroni - INFN Milano-Bicocca BCVEGPY in CMSSW First step: Run the generator as stand alone to reproduce the significant distributions ( and ) reported in Comput.Phys.Commun. 174 (2006) 241-251 17th June 2008 Silvia Taroni - INFN Milano-Bicocca

Comparison at the TeV energy Comput.Phys.Commun. 174 (2006) 241-251 From BCVEGPY 17th June 2008 Silvia Taroni - INFN Milano-Bicocca GeV y

Silvia Taroni - INFN Milano-Bicocca BCVEGPY in CMSSW Second step interface BCVEGPY to CMSSW. local customized CMSSW version (which include the generator) with the option to call the generator via a modified PythiaSource.cc in PYTHIA6Interface. untracked bool UseExternalGenerators = true PSet ExternalGenerators = { vstring parameterSets = { "Bcvegpy" } untracked PSet Bcvegpy = { vstring InputCards = { "BCVEGPY" Call in .cfg file 17th June 2008 Silvia Taroni - INFN Milano-Bicocca

Pseudorapidity and Pt @ LHC from CMSSW pseudorapidity and transverse momentum distributions. dN/dη /Ntot dN/dpt /Ntot 17th June 2008 Silvia Taroni - INFN Milano-Bicocca GeV

Silvia Taroni - INFN Milano-Bicocca dN/dpt /Ntot Third step: double check CMSSW and the Stand Alone Generator @14 TeV GeV BCVEGPY stand alone dN/dη /Ntot 17th June 2008 Silvia Taroni - INFN Milano-Bicocca η

Conclusions and Outlook The BCVEGPY Generator (already used in ORCA, CDF and D0) is now working in CMSSW. We tested it in a local customized code and checked with reference distributions. We ask the B-Physics WG the green light to go to the Generator WG to implement it in the official generator interface. We are now ready to go to Bc Physics and enjoy ourselves ! 17th June 2008 Silvia Taroni - INFN Milano-Bicocca

Using the new Bc generator Full simulation chain for Track selection: more than 8 hits, pt > 2.5 GeV/c Global muons for muon candidates vertex (three tracks) C.L >0.01 Preliminary GeV 17th June 2008 Silvia Taroni - INFN Milano-Bicocca

Silvia Taroni - INFN Milano-Bicocca backup 17th June 2008 Silvia Taroni - INFN Milano-Bicocca

Silvia Taroni - INFN Milano-Bicocca BCEVGPY stand alone. Rapidity dN/dy/Ntot y 17th June 2008 Silvia Taroni - INFN Milano-Bicocca

Silvia Taroni - INFN Milano-Bicocca From BCVEGPY @ 1.96 TeV 17th June 2008 Silvia Taroni - INFN Milano-Bicocca