simulation for cms hi
DESCRIPTION
Simulation for CMS HI. Dipanwita Dutta Nuclear Physics Division Bhabha Atomic Research centre Mumbai, India. Outline. Part I. Cross-section of Z 0 (PYTHIA). Simulation and Reconstruction of Z 0 with CMKIN+OSCAR+ORCA. Muon Reconstruction with CMSSW. Part II. - PowerPoint PPT PresentationTRANSCRIPT
Dipanwita Dutta 5-6 April,2007, India-CMS Meet, Chandigarh
Simulation for CMS HI
Dipanwita Dutta
Nuclear Physics Division
Bhabha Atomic Research centre
Mumbai, India
Dipanwita Dutta 5-6 April,2007, India-CMS Meet, Chandigarh
Outline
•Cross-section of Z0 (PYTHIA)
•Future Plan: Simulation for Small mass dimuon / Real Photon with CMS
•Simulation and Reconstruction of Z0
with CMKIN+OSCAR+ORCA
Part I
•Muon Reconstruction with CMSSWPart II
Dipanwita Dutta 5-6 April,2007, India-CMS Meet, Chandigarh
Cross-Section of Z0 (PYTHIA)
0Zqq
0Z)q(qg)q(q
Total
pp(Z
0)
(nb/
GeV
)
Z0 pT (GeV)
For Pb-Pb minbias collision at 5.5 TeV
(Z0+-)
B A2pp(Z0)
68 b
Dipanwita Dutta 5-6 April,2007, India-CMS Meet, Chandigarh
Cross-section and No. of Z0 for Pb+Pb collision s=5.5 TeV for Lint=0.5 nb-1
ProcessesCross-section from PYTHIA pp (Z
0)
PDF CTEQ5M
Cross-section from PYTHIA pp (Z0) PDF
CTEQ5ML
No. of Z0 for central collision (CTEQ5M)
AA=TAA(0)NNpp (Z0)
No. of Z0 for minbias collisionAA=A2 pp (Z
0)
Z0, Z0+jet 48 nb 54 nb 4.3104 1.03106
Z0 16 nb 17.5 nb 1.4104 3.4105
For CMSpT>3.5 GeV
<2.4
Z0, Z0+jet
8.910-1 nb 9.510-1 nb 800 1.9104
mZ-5<M<
mZ+5
6.910-1 nb 7.710-1 nb 621 1.4104
Z0 2.810-1 nb 257 6020
Dipanwita Dutta 5-6 April,2007, India-CMS Meet, Chandigarh
Differential and Integrated Rate of Z0 inPb+Pb collision , s=5.5 TeV for Lint=0.5 nb-1
Barrel+Endcap
│
Barrel only
Dipanwita Dutta 5-6 April,2007, India-CMS Meet, Chandigarh
●
Muon Reconstruction
•Local Muon Reconstruction (L1)
•Stand-Alone Muon Reconstruction (L2)
•Global Muon Reconstruction (L3)
(Combined with Tracker)
•Tag from Muon chambers•Momentum resolution from Silicon Tracker
Dipanwita Dutta 5-6 April,2007, India-CMS Meet, Chandigarh
Simulation of Z0 +- channel
Gen. vs. Rec. Muon from ORCA
pT (GeV)
GenRec
Dipanwita Dutta 5-6 April,2007, India-CMS Meet, Chandigarh
Reconstruction without backgroundStand Alone Muon Reconstruction
Dipanwita Dutta 5-6 April,2007, India-CMS Meet, Chandigarh
Reconstruction with HI BackgroundStand Alone Muon Reconstruction
Dipanwita Dutta 5-6 April,2007, India-CMS Meet, Chandigarh
Summary : CMKIN-OSCAR-ORCA
• Generation, Simulation and Reconstruction of Z0 performed with HI background using full CMS simulation package CMKIN, OSCAR, ORCA
• Stand Alone Muon Reconstruction show poor mass resolution, Mass width~ 18 GeV at Z0 mass (m/m~0.2)
• Global Muon Reconstruction with Tracker: Mass Resolution with HI background to be studied --- No further Support for ORCA
• Mass Resolution remains unaltered with HI background using Stand Alone Muon Reconstruction
Dipanwita Dutta 5-6 April,2007, India-CMS Meet, Chandigarh
Reconstruction with CMSSW
• CMSSW_1_2_2 downloaded and installed locally at BARC
• Muon Reconstruction using CMSSW: Software available for pp, Reconstruction algorithms for HI under development
• Involvement of BARC for HI Software transportation to CMSSW is required --Olga
• Reconstruction using pp algorithm: Z0 Generation with PYTHIA using CMSSW Generator Interface -- Simulation+ Digitization--Local + Stand Alone Muon Reconstruction
Dipanwita Dutta 5-6 April,2007, India-CMS Meet, Chandigarh
Muon Reconstruction with CMSSW
PT distribution of Generated and Reconstructed muons
Dipanwita Dutta 5-6 April,2007, India-CMS Meet, Chandigarh
Generated and Reconstructed Invariant Mass
m ~ 14 GeV
Dipanwita Dutta 5-6 April,2007, India-CMS Meet, Chandigarh
Direct Photons at Low pT – RHIC Result
QM 2005: Data consistent with thermal+ NLO pQCD
pQCD uncertain at low pT
Gordon and Vogelsang Phys. Rev. D48, 3136 (1993)
Thermal d’Enterria, Perresounko Eur.Phys.J.C46:451-464,2006
(a) New experimental method for the measurement of
.. / incldirectincl
Dipanwita Dutta 5-6 April,2007, India-CMS Meet, Chandigarh
Future Plan
• Simulation for low mass Dimuon/Photon channel-- Background muons – (DY and open charm and bottom)
• Study the Thermal Dilepton signal (theoretical prediction) and possibility to see the effect of Chemical unsaturation
• Involvement in transportation as well as improvement of reconstruction HI softwares from OSCAR, ORCA to CMSSW
• Global Muon Reconstruction with Tracker information included in CMSSW for
Z0 +-