Study of direct photon plus jet production in CMS experiment at $\sqrt{s}$ = 14 TeV

We present simulation results of $\gamma$ + Jet analysis using CMS (Compact Muon Solenoid) Object-Oriented software at the LHC center of mass energy ($\sqrt{s}$=14 TeV). The study of direct photon production helps in validating the perturbative quantum chromodynamics (pQCD) and constraining the gluon distribution of nucleons. Direct photon processes also represent a major contribution in estimating background to other Standard Model (SM) processes and signals of new physics. Thus these processes need to be understood precisely in the new energy regime mentioned above. In this work, we have done a detailed study of the complete GEANT4 simulated events of $\gamma$ + jet generated with Pythia and the related background processes at $\sqrt{s}$=14 TeV. Isolation cuts have been defined for the direct photon which improves the signal to background ratio by $\sim25%$ as compared to previous studies done in CMS. The inclusion of a $\Delta\phi$ cut at $40^0$ in the analysis leads to a further increase of $\sim15-17%$, thus giving an overall gain of $\sim42%$ in S/B ratio.