The WZ production cross section in proton-proton collisions at √ s = 13 TeV is measured with the CMS experiment at the LHC using a data sample corresponding to an integrated luminosity of 2.3 fb −1 . The measurement is performed in the leptonic decay modes WZ → ν , where , = e, µ. The measured cross section for the range 60 < m < 120 GeV is σ(pp → WZ) = 39.9 ± 3.2 (stat) +2.9 −3.1 (syst) ± 0.4 (theo) ± 1.3 (lumi) pb, consistent with the standard model prediction.The CMS detector is described in detail elsewhere [8]. The key components for this analysis are summarized here. The central feature of the CMS apparatus is a superconducting solenoid of 6 m internal diameter, providing a magnetic field of 3.8 T. Within the superconducting solenoid volume are a silicon pixel and strip tracker, a lead tungstate crystal electromagnetic calorimeter (ECAL), and a brass and scintillator hadron calorimeter, which provide the pseudorapidity coverage |η| < 1.479 in a barrel section and 1.479 < |η| < 3.0 in two endcap sections. Forward calorimeters extend the coverage to |η| < 5.0. Muons are measured in gas-ionization detectors embedded in the steel flux-return yoke outside the solenoid.The first level of the CMS trigger system, composed of custom hardware processors, is designed to select the most interesting events in less than 4 µs using information from the calorimeters and muon detectors. The high-level-trigger processor farm decreases the event rate from almost 100 kHz to around 1 kHz, before data storage. Data and Monte Carlo samplesThis measurement uses a sample of proton-proton collisions collected in 2015 at √ s = 13 TeV. The integrated luminosity of the sample is 2.3 fb −1 . Several Monte Carlo (MC) event generators are used to simulate the signal and background processes.The WZ signal is generated at NLO in perturbative QCD with POWHEG 2.0 [9][10][11][12]. The ZZ production via qq annihilation is generated at NLO using POWHEG 2.0, while the gg → ZZ 2 4 Event reconstruction process is simulated at leading-order with MCFM 7.0 [13]. The Zγ, ttV (ttW, ttZ), tZ, and triboson events VVV (WWZ, WZZ, ZZZ) are generated at NLO with MADGRAPH5 AMC@NLO [14]. The ZZ samples are scaled to the cross section calculated at NNLO for qq → ZZ [15] (scaling k factor 1.1) and at NLO for gg → ZZ [16] (scaling k factor 1.7). The PYTHIA 8.175 [17] program is used for parton showering, hadronization, and underlying event simulation using the CUETP8M1 tune [18]. The NNPDF3.0 [19] set of parton distribution functions (PDFs) is used, unless otherwise specified.For all processes, the detector response is simulated using a detailed description of the CMS detector, based on the GEANT4 package [20], and the event reconstruction is performed with the same algorithms used for data. The simulated samples include additional interactions per bunch crossing (pileup) taken from minimum-bias events generated with PYTHIA. The simulated events are weighted so that the pileup distribution matches the measured one, with an average of about 11 pileup interactions p...

Measurements of strange hadron (View the MathML sourceKS0, View the MathML sourceΛ+Λ‾, and View the MathML sourceΞ−+Ξ‾+) transverse momentum spectra in pppp, pPbpPb, and PbPb collisions are presented over a wide range of rapidity and event charged-particle multiplicity. The data were collected with the CMS detector at the CERN LHC in pppp collisions at View the MathML sources=7TeV, pPbpPb collisions at View the MathML sourcesNN=5.02TeV, and PbPb collisions at View the MathML sourcesNN=2.76TeV. The average transverse kinetic energy is found to increase with multiplicity, at a faster rate for heavier strange particle species in all systems. At similar multiplicities, the difference in average transverse kinetic energy between different particle species is observed to be larger for pppp and pPbpPb events than for PbPb events. In pPbpPb collisions, the average transverse kinetic energy is found to be slightly larger in the Pb-going direction than in the p-going direction for events with large multiplicity. The spectra are compared to models motivated by hydrodynamics

Amorphous sulfur (a-S) with excellent stability is obtained by rapid compression method. The prepared a-S has a single glassy phase and exhibits a wide supercooled liquid region of 112 K and much high thermal and kinetic stability at room temperature compared to that of conventional a-S fabricated by quenched method. The substantial improved thermal and kinetic stability is attributed to low energy state induced by rapid compressing process. The stable a-S is a model system for facilitating the studies of the nature of glasses and supercooled liquids.

The CMS tracker consists of 206 m 2 of silicon strip sensors assembled on carbon fibre composite structures and is designed for operation in the temperature range from −25 to +25 • C. The mechanical stability of tracker components during physics operation was monitored with a few µm resolution using a dedicated laser alignment system as well as particle tracks from cosmic rays and hadron-hadron collisions. During the LHC operational period of 2011-2013 at stable temperatures, the components of the tracker were observed to experience relative movements of less than 30 µm. In addition, temperature variations were found to cause displacements of tracker structures of about 2 µm/ • C, which largely revert to their initial positions when the temperature is restored to its original value.