Observation of the diphoton decay mode of the recently discovered Higgs boson and measurement of some of its properties are reported. The analysis uses the entire dataset collected by the CMS experiment in proton-proton collisions during the 2011 and 2012 LHC running periods. The data samples correspond to integrated luminosities of 5.1at and 19.7at 8 . A clear signal is observed in the diphoton channel at a mass close to 125 with a local significance of , where a significance of is expected for the standard model Higgs boson. The mass is measured to be , and the best-fit signal strength relative to the standard model prediction is . Additional measurements include the signal strength modifiers associated with different production mechanisms, and hypothesis tests between spin-0 and spin-2 models.

The transverse momentum spectra of charged particles have been measured in pp and PbPb collisions at √ s NN = 2.76 TeV by the CMS experiment at the LHC. In the transverse momentum range p T = 5-10 GeV/c, the charged particle yield in the most central PbPb collisions is suppressed by up to a factor of 7 compared to the pp yield scaled by the number of incoherent nucleon-nucleon collisions. At higher p T , this suppression is significantly reduced, approaching roughly a factor of 2 for particles with p T in the range p T = 40-100 GeV/c.

Searches for the direct electroweak production of supersymmetric charginos, neutralinos, and sleptons in a variety of signatures with leptons and , , and Higgs bosons are presented. Results are based on a sample of proton-proton collision data collected at center-of-mass energy with the CMS detector in 2012, corresponding to an integrated luminosity of 19.5 . The observed event rates are in agreement with expectations from the standard model. These results probe charginos and neutralinos with masses up to 720 , and sleptons up to 260 , depending on the model details.

A search for a standard model Higgs boson decaying into a pair of tau leptons is performed using events recorded by the CMS experiment at the LHC in 2011 and 2012. The dataset corresponds to an integrated luminosity of 4.9 inverse-femtobarns at a centre-of-mass energy of 7 TeV, and 19.7 inverse-femtobarns at 8 TeV. Each tau lepton decays hadronically or leptonically to an electron or a muon, leading to six different final states for the tau-lepton pair, all considered in this analysis. An excess of events is observed over the expected background contributions, with a local significance larger than 3 standard deviations for mH values between 115 and 130 GeV. The best fit of the observed H→τ−τ signal cross section for mH = 125 GeV is 0.78 +/- 0.27 times the standard model expectation. These observations constitute evidence for the 125 GeV Higgs boson decaying to a pair of tau leptons

A search for new physics is performed in multijet events with large missing transverse momentum produced in proton-proton collisions at √ s = 8 TeV using a data sample corresponding to an integrated luminosity of 19.5 fb −1 collected with the CMS detector at the LHC. The data sample is divided into three jet multiplicity categories (3-5, 6-7, and ≥8 jets), and studied further in bins of two variables: the scalar sum of jet transverse momenta and the missing transverse momentum. The observed numbers of events in various categories are consistent with backgrounds expected from standard model processes. Exclusion limits are presented for several simplified supersymmetric models of squark or gluino pair production. 3 Sample selectionAll these backgrounds are determined using the data, with as little reliance on simulation as possible. The CMS detector and event reconstructionThe CMS detector is a multipurpose apparatus, described in detail in Ref. [5]. The CMS coordinate system is defined with the origin at the centre of the detector and the z axis along the anticlockwise beam direction. The polar angle θ is measured with respect to the z axis, and the azimuthal angle φ (measured in radians) in the plane perpendicular to that axis. Chargedparticle trajectories are measured with a silicon pixel and strip tracker, covering |η| < 2.5, where the pseudorapidity η is defined as η = − ln[tan(θ/2)]. Immersed in the 3.8 T magnetic field provided by a 6 m diameter superconducting solenoid, which also encircles the calorimeters, the tracking system provides transverse momentum (p T ) resolution of approximately 1.5% for charged particles with p T ∼ 100 GeV. A lead-tungstate crystal electromagnetic calorimeter and a brass-and-scintillator hadron calorimeter surround the tracking volume and cover the region |η| < 3. Steel and quartz-fibre hadron forward calorimeters extend the coverage to |η| ≤ 5. Muons are identified in gas ionization detectors embedded in the steel flux return yoke of the magnet. The events used for this search are recorded using a two-level trigger system described in Ref. [5].The recorded events are required to have at least one well-identified interaction vertex with z position within 24 cm from the nominal centre of the detector and transverse distance from the z axis less than 2 cm. The primary vertex is the one with the largest sum of p T -squared of all the associated tracks, and is assumed to correspond to the hard-scattering process. The events are reconstructed using a particle-flow (PF) algorithm [23]. This algorithm reconstructs a list of particles in each event, namely charged and neutral hadrons, photons, muons, and electrons, combining the information from the tracker, the calorimeters, and the muon system. These particles are then clustered into jets using the anti-k T clustering algorithm [24] with a size parameter of 0.5. Contributions from additional pp collisions overlapping with the event of interest (pileup) are mitigated by discarding charged particles not associated with the primary vert...