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The cross sections of Z-boson and b-quark(jet) is experimentally measured by CMS and ATLAS at the Large Hadron Collider (LHC) in proton-proton col- lisions at various center of mass energies. Theoretically predicted cross sec- tion of the Z-boson and b-quark(jet) production in proton-proton collisions at $\sqrt{s}$= 13TeV , $\sqrt{s}$= 13.6TeV and $\sqrt{s}$= 14TeV are presented in this thesis. The Z-boson and b-quark(jet) production cross section measurement at hadron collision provides a deep understanding of quantum chromodynamics (QCD) and electroweak (EW) processes. The production of Z-bosons and b-quarks(jet) are best examples of hard scattering processes at Large Hadron Collider. The- oretical predictions in perturbative chromodynamics are available at next-to- Leading order (NLO). Theoretically predicted cross-sections are compared with the measured re- sults at various center of mass energies. Kinematics of b-quarks are also pre- sented. Measured cross-sections are compared to predictions from the Monte Carlo gen- erator (MADGRAPH5) based on leading-order (LO) or next-to-leading-order (NLO) matrix elements interfaced with pythia parton-shower simulation and evaluating several flavour approaches for the choice of initial-state partons. At NLO accuracy,The 5-flavour number scheme predictions accord better with data than 4-flavour number scheme predictions. In occurrences involving at least one b-quark(jet), the 4-flavour number method underpredicts data. |
