Recent results of the searches for Supersymmetry in final states with one or two leptons at CMS are presented. Many Supersymmetry scenarios, including the Constrained Minimal Supersymmetric extension of the Standard Model (CMSSM), predict a substantial amount of events containing leptons, while the largest fraction of Standard Model background events -which are QCD interactions -gets strongly reduced by requiring isolated leptons. The analyzed data was taken in 2011 and corresponds to an integrated luminosity of approximately L = 1 fb −1 . The center-of-mass energy of the pp collisions was √ s = 7 TeV.

Optical links are being developed to transfer analogue tracking data and digital timing and control signals in the future Compact Muon Solenoid (CMS) experiment at CERN. The radiation environment inside the CMS tracker will be extreme, with hadron fluences up to -10i4/cm2 and ionising doses of -100kGy over the experimental lifetime. Prototype link elements, consisting of commercially available 13 lOnm multi-quantum-well InGaAsP lasers and InGaAs p-i-n photodiodes, have been irradiated in a fully packaged form with -6MeV neutrons to 10'5n/~m2, 24GeV protons to 4x10i4p/cm2 and '"Co-gammas to 100kGy. Three types of single-mode optical fiber, two pure-silica core and one Gedoped core, were irradiated in several stages with 6oCo-gammas to a total dose of -90kGy.Neutron and proton damage induced large increases in laser threshold and significant decreases in light output efficiency. P-i-n leakage current increased by up to 6-7 orders of magnitude for neutron and proton damage. P-i-n response was relatively unaffected until -2x 10'4n/cm2, or -4~1 0~~p / c m~, after which the photocurrent decreased rapidly. Gamma damage after lOOkGy was minor in comparison to hadron damage in both the lasers and p-i-n photodiodes. The radiation induced attenuation at 1300nm in the optical fibers was dependent upon the fiber type, with losses of O.OBdB/m for the pure-silica core fiber and 0.12dBIm in the Ge-doped core fiber, after -90kGy. The annealing in one of the pure-silica core fibers was found to be temporary in nature.

Charmed-meson production by 350 GeV/c particles incident on copper and tungsten targets has been studied in the WA92 experiment, performed at the CERN 0 spectrometer. Results obtained are reported and discussed. Reconstruction of decays from the set D 0 ! K + , D 0 ! K + + , D + ! K + + , D s + ! + and charge conjugates has yielded a sample of 7280 108 charmed mesons, produced with X F > 0, hX F i = 0:18 and hp T 2 i = 1:86 (GeV=c) 2 . Assuming a relationship = 0 A between the cross-section, , per nucleus of mass A and the nucleonic cross-section, 0 , the value found for the detected charmed particles is 0:95 0:06 0:03. Taking = 1 , the measured cross-sections per nucleon for X F > 0 production are 7:780:140:52 barn for D 0 / D 0 , 3 : 280:080:29 barn for D + /D and 1:29 0:16 0:33 barn for D s + /D s . Dierential cross-sections with respect to X F and p T 2 have been determined for the various types of charmed meson, and particle-antiparticle asymmetries have been analysed.

Optical data links are being developed at CERN for use in the tracking system of the Compact Muon Solenoid (CMS) experiment to be operated at the future CERN Large Hadron Collider. The radiation environment will be severe in the CMS tracker; simulations predict hadronic fluences >10 14 /cm 2 over an experimental lifetime of ten years, consisting of a mixture of neutrons, pions and protons over a wide energy spectrum, plus an ionizing dose of ~100kGy. Candidate optical link components must therefore be qualified for sufficient radiation hardness. Results are presented for commercially available InGaAsP lasers and InGaAs p-i-n photodiodes irradiated with 330MeV pions up to 5.4x10 14 π/cm 2 . The evolution of the laser threshold and efficiency with fluence is presented, in addition to the leakage current and photocurrent in the photodiodes. Comparisons are drawn with previous irradiation tests on identical devices using 6MeV neutrons and 24GeV protons, and ionizing damage due to 60 Co gamma rays.

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