Abstract
We present simulation results of γ+jet analysis using CMS (compact muon solenoid) object-oriented software at the large hadron collider (LHC) center of mass energy \(\sqrt{s}\) = 14 TeV. The study of direct photon production helps in validating the perturbative quantum chromodynamics (pQCD) and providing information on the gluon distribution in the nucleons. Direct photon processes also constitute a major background to several other standard model (SM) processes and signals of new physics. Thus these processes need to be understood precisely in the new energy regime. In this work, we have done a detailed study of the GEANT4 simulated γ+jet events generated with Pythia, and the related background processes. Isolation cuts have been optimized for direct photon which improves the signal over background ratio by ∼25% as compared to previous studies done in CMS. The inclusion of a large Δφ cut between the photon and the leading jet at 40° in the analysis leads to a further increase of ∼15% in S/B, thus giving an overall gain of ∼42% in S/B ratio.
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References
P. Aurenche et al., Phys. Rev. D 42, 1440 (1990)
E.C. Reid at al., “Direct Photon in CMS”, CMS NOTE-2000/063
D.V. Bandourin, V.F. Konoplyanikov, hep-ex/0207028
D.V. Bandourin, N.B. Skachkov, “On the Possibilities of Measuring the Gluon Distribution Using photon/Z0+jet Events at Tevatron Run II and LHC”, Contributed to Proc. of XI International Workshop on Deep Inelastic Scattering “DIS 2003”, St. Petersburg, April 23–27, 2003, hep-ex/0403024
M. Pieri et al., “Inclusive search for the Higgs Boson in the H→γγ channel”, CMS NOTE-2006/112
F. Abe et al., Phys. Rev. Lett. 76, 2852 (1996)
N. Arkani-Hamed et al., Phys. Lett. B 429, 263 (1998)
J. Weng et al., “Search for ADD direct graviton emission in photon plus missing transverse energy final state at CMS”, CMS NOTE-2006/129
CDF Collaboration, A. Abulencia et al., Phys. Rev. Lett. 99, 1217801 (2007)
L. Apanasevich et al., Phys. Rev. Lett. 81, 2642 (1998)
V.M. Abazov et al., Phys. Lett. B 639, 151 (2006)
B. Abbott et al., Phys. Rev. Lett. 84, 2786 (2000)
D. Ascota et al., Phys. Rev. D 65, 112003 (2002)
D. Ascota et al., Phys. Rev. Lett. 87, 251807 (2001)
D. Ascota et al., Phys. Rev. D 70, 074008 (2004)
D0 Collaboration, contributed to the Proc. of 2007 Europhysics Conference on High Energy Physics, Manchester, UK, arXiv:0710.0415v1[hep-ex]
T. Binoth at al., Eur. Phys. J. C 16, 311 (2000)
S. Catani at al., JHEP 0205, 028 (2002)
J. Pumplin et al., JHEP 0207, 012 (2002)
D. Stump et al., JHEP 0310, 046 (2003)
A. Kumar et al., Phys. Rev. D 68, 014017 (2003)
L. Apanasevich et al., Phys. Rev. D 59, 074007 (1999)
L. Agostino, M. Pieri, “High Level Trigger Selection of Electrons and Photons”, CMS NOTE-2006/078
CMKIN, “CMS Interface for Event Generator”, http://cmsdoc.cern.ch/cmsoo/projects/CMKIN
OSCAR, “Object-oriented Simulation for CMS Analysis and Reconstruction”, http://cmsdoc.cern.ch/OSCAR
ORCA, “Object-oriented Reconstruction for CMS Analysis”, http://cmsdoc.cern.ch/orca
J.P. Ralston, Phys. Lett. B 172, 430 (1986)
CMS Collaboration, “CMS Tracker Technical Design Report”, CERN/LHCC 98-6
CMS Collaboration, “Addendum to the CMS Tracker TDR”, CERN/LHCC 2000-016
CMS Collaboration, “CMS Physics Technical Design Report Volume I”, CERN/LHCC 2006-001
CMS Collaboration, “CMS ECAL Technical Design Report”, CERN/LHCC 97-33
CMS Collaboration, “CMS HCAL Technical Design Report”, CERN/LHCC 97-31
CMS Collaboration, “CMS Muon Technical Design Report”, CERN/LHCC 97-32
E. Meschi et al., “Electron Reconstruction at CMS Electromagnetic Calorimeter”, CMS NOTE-2001/034
T. Sjostrand, P.Z. Skands, Eur. Phys. J. C 39, 129 (2005)
H. Baer at al., Phys. Rev. D 42, 61 (1990)
J. Owens, private communications
CMS Collaboration, “The Tridas Project Design Report, Volume II: Data Acquisition and High-Level Trigger”, CERN/LHCC 2002-26
S. Baffioni et al., “Discovery potential for the SM Higgs boson in the H→ZZ→e+e-e+e- decay channel”, CMS NOTE-2005/115
CMS Collaboration, G.L. Bayatian et al., J. Phys. G 34, 995 (2007)
H1 Collaboration, A. Akläs et al., Eur. Phys. J. C 38, 437 (2005)
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Gupta, P., Choudhary, B., Chatterji, S. et al. Study of direct photon plus jet production in CMS experiment at \(\sqrt{s}\) = 14 TeV. Eur. Phys. J. C 53, 49–58 (2008). https://doi.org/10.1140/epjc/s10052-007-0460-y
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DOI: https://doi.org/10.1140/epjc/s10052-007-0460-y