The compact muon solenoid (CMS) is one of the four experiments which is getting and analysing the results of the collision of protons at LHC. The CMS trigger system is divided into two stages, the level-1 trigger and high-level triggers, to handle the large stream of data produced in collision. The information transmitted from the three muon subsystems (DT, CSC and RPC) are collected by the Global Muon Trigger (GMT) Board and merged. A method for evaluating the RPC system trigger efficiency with data from $pp$ collision was developed using the features of GMT. The results of the study with the real data of 2011 are shown and discussed here along with the comparison of Monte Carlo results

A search is reported for the Higgs boson decaying to $W^{+} W^{−}$ in pp collisions at $\sqrt{s} = 7$ TeV. The analysis is performed using LHC data recorded by the CMS detector, corresponding to an integrated luminosity of 1.55 fb^-1. No significant excess above the Standard Model background expectation is observed, and upper limits on Higgs boson production are derived, excluding the presence of a Higgs boson with a mass in the range of 147–194 GeV/c² at the 95% confidence level (CL) using the CLs approach.

The measurements of the cross-sections are presented for the production of jets in association with 𝑊 and 𝑍 bosons reconstructed in their decays to electrons and muons. The results are based on 36 pb^-1 of $pp$ collisions at $\sqrt{s} = 7$ TeV collected by the CMS Collaboration. Jets are reconstructed with the CMS particle flow algorithm and must pass a transverse momentum threshold of 30 GeV. The study presents the ratios $\sigma (V + \geq n-{\text{jet}})/\sigma (V)$ and $\sigma (V + \geq n-{\text{jet}})/\sigma(V + \geq (n - 1)-{\text{jet}}).$ The comparison between the data and the Monte Carlo prediction is also showed.