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.

Measurements of the fine-structure constant α require methods from across subfields and are thus powerful tests of the consistency of theory and experiment in physics. Using the recoil frequency of cesium-133 atoms in a matter-wave interferometer, we recorded the most accurate measurement of the fine-structure constant to date: α = 1/137.035999046(27) at 2.0 × 10 accuracy. Using multiphoton interactions (Bragg diffraction and Bloch oscillations), we demonstrate the largest phase (12 million radians) of any Ramsey-Bordé interferometer and control systematic effects at a level of 0.12 part per billion. Comparison with Penning trap measurements of the electron gyromagnetic anomaly - 2 via the Standard Model of particle physics is now limited by the uncertainty in - 2; a 2.5σ tension rejects dark photons as the reason for the unexplained part of the muon's magnetic moment at a 99% confidence level. Implications for dark-sector candidates and electron substructure may be a sign of physics beyond the Standard Model that warrants further investigation.

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We experimentally and theoretically study the diffraction phase of large-momentum transfer beam splitters in atom interferometers based on Bragg diffraction. We null the diffraction phase and increase the sensitivity of the interferometer by combining Bragg diffraction with Bloch oscillations. We demonstrate agreement between experiment and theory, and a 1500-fold reduction of the diffraction phase, limited by measurement noise. In addition to reduced systematic effects, our interferometer has high contrast with up to 4.4 million radians of phase difference, and a resolution in the fine structure constant of δα/α = 0.25 ppb in 25 hours of integration time.PACS numbers: 03.75. Dg, 37.25.+k, 06.20.Jr, 06.30.Dr Atom interferometers are a direct analogy to optical interferometers, where beam splitters and mirrors send a wave along two different trajectories. When the waves are recombined, they can interfere constructively or destructively, depending upon the phase difference ∆φ accumulated between the paths. In light-pulse atom interferometers, atomic matter waves are coherently split and reflected using atom-photon interactions, which impart photon momenta k to the atoms.In a Ramsey Bordé interferometer, for example, the atom (of mass m) moves away and back along one path while remaining in constant inertial motion along the other path. The phase difference ∆φ = 8ω r T (T is the pulse separation time) is proportional to the kinetic energy, and thus to the recoil frequency ω r = k 2 /(2m). This enables state-of-the-art measurements of the fine structure constant α [1] and will help realize the expected new definition of the kilogram in terms of the Planck constant [2,3]. Using multiphoton Bragg diffraction [4,5] and simultaneous operation of conjugate interferometers [6], the phase difference has been increased to Φ = 16n 2 ω r T (where the factor of 16 arises from taking the phase difference of the two interferometers), and Earth's gravity and vibrations have been canceled. Unfortunately, however, Bragg diffraction causes a diffraction phase [2, 7-9], which has been the largest systematic effect in high-sensitivity atom interferometers using this technique [2]. Here, we study the diffraction phase in detail and show that it can be suppressed and even nulled by introducing Bloch oscillations as shown in Fig. 1 A, B. Bloch oscillations also increase the measured phase shift towhere n > 1. We decrease the influence of diffraction phases by an amount that is considerably larger than the increase in sensitivity and are in fact able to null them by feedback to the laser pulse intensity. With this increase in signal and suppression of diffraction phase systematics, we expect to see improvements in many applications of atom interferometry, such as measuring gravity and inertial effects [10][11][12][13]