Combined measurements of the production and decay rates of the Higgs boson, as well as its couplings to vector bosons and fermions, are presented. The analysis uses the LHC proton–proton collision data set recorded with the CMS detector in 2016 at , corresponding to an integrated luminosity of 35.9 . The combination is based on analyses targeting the five main Higgs boson production mechanisms (gluon fusion, vector boson fusion, and associated production with a or boson, or a top quark-antiquark pair) and the following decay modes: , , , , , and . Searches for invisible Higgs boson decays are also considered. The best-fit ratio of the signal yield to the standard model expectation is measured to be , assuming a Higgs boson mass of . Additional results are given for various assumptions on the scaling behavior of the production and decay modes, including generic parametrizations based on ratios of cross sections and branching fractions or couplings. The results are compatible with the standard model predictions in all parametrizations considered. In addition, constraints are placed on various two Higgs doublet models.

The performance of missing transverse energy reconstruction algorithms is presented using √ s = 8 TeV proton-proton (pp) data collected with the CMS detector. Events with anomalous missing transverse energy are studied, and the performance of algorithms used to identify and remove these events is presented. The scale and resolution for missing transverse energy, including the effects of multiple pp interactions (pileup), are measured using events with an identified Z boson or isolated photon, and are found to be well described by the simulation. Novel missing transverse energy reconstruction algorithms developed specifically to mitigate the effects of large numbers of pileup interactions on the missing transverse energy resolution are presented. These algorithms significantly reduce the dependence of the missing transverse energy resolution on pileup interactions. Finally, an algorithm that provides an estimate of the significance of the missing transverse energy is presented, which is used to estimate the compatibility of the reconstructed missing transverse energy with a zero nominal value.

The performance of all subsystems of the CMS muon detector has been studied by using a sample of proton-proton collision data at √ s = 7 TeV collected at the LHC in 2010 that corresponds to an integrated luminosity of approximately 40 pb −1 . The measured distributions of the major operational parameters of the drift tube (DT), cathode strip chamber (CSC), and resistive plate chamber (RPC) systems met the design specifications. The spatial resolution per chamber was 80-120 µm in the DTs, 40-150 µm in the CSCs, and 0.8-1.2 cm in the RPCs. The time resolution achievable was 3 ns or better per chamber for all 3 systems. The efficiency for reconstructing hits and track segments originating from muons traversing the muon chambers was in the range 95-98%. The CSC and DT systems provided muon track segments for the CMS trigger with over 96% efficiency, and identified the correct triggering bunch crossing in over 99.5% of such events. The measured performance is well reproduced by Monte Carlo simulation of the muon system down to the level of individual channel response. The results confirm the high efficiency of the muon system, the robustness of the design against hardware failures, and its effectiveness in the discrimination of backgrounds. Overview of the muon system Overview of the muon systemThe basic detector process utilized in the CMS muon systems is gas ionization. For all the different technologies-drift tubes, cathode strip proportional planes, and resistive platesthe basic physical modules are called "chambers". The chambers are independently-operating units, which are assembled into the overall muon detector system of CMS. The chambers form part of a spectrometer in which the analyzing magnet is the central solenoid together with the flux return yoke of CMS. To match the cylindrical geometry of the solenoid, the barrel region is instrumented with drift tube chambers, and the 2 endcap regions with cathode strip chambers. Resistive plate chambers are interspersed in both the barrel and endcap regions. The muon chambers must detect the traversing track at several points along the track path to utilize the magnet to measure the deflection of muons as they pass through its field. In the barrel region, this requires chambers to be positioned at several different values of the radial distance R from the beam line, and in the endcap region at several different values of distance along the beam direction z. A "station" is an assembly of chambers around a fixed value of R (in the barrel) or z (in the endcap). There are 4 stations in the barrel and in each endcap (Fig. 1), labeled MB1-MB4 and ME1-ME4, respectively. Along z, the drift tubes and resistive plate chambers in the barrel are divided into 5 "wheels", with Wheel 0 centered at z = 0 and wheels W+1 and W+2 in the +z direction and W-1 and W-2 in the −z direction. Similarly in the R direction in the endcaps, there are "rings" of endcap resistive plate chambers and cathode strip chambers. The latter are labeled ME1/n-ME4/n, where integer n increases with the radia...

Abstract. The capabilities of the CMS experiment to study the low-x parton structure and QCD evolution in the proton and the nucleus at LHC energies are presented through four different measurements, to be carried out in Pb-Pb at √ s NN = 5.5 TeV: (i) the charged hadron rapidity density dN ch /dη and (ii) the ultraperipheral (photo)production of Υ; and in p-p at √ s = 14 TeV: (iii) inclusive forward jets and (iv) Mueller-Navelet dijets (separated by ∆η 8).

The CMS collaboration has developed a fast Monte Carlo simulation of the CMS detector with event production rates 100-1000 times faster than the GEANT4-based simulation, with comparable accuracy. This paper discusses the simulation of particle propagation in the CMS detector and the response of the different parts of the detector: the silicon tracker, the electromagnetic calorimeter, the hadronic calorimeter and the muon system.