Measurements of the jet energy calibration and transverse momentum resolution in CMS are presented, performed with a data sample collected in proton-proton collisions at a centreof-mass energy of 7 TeV, corresponding to an integrated luminosity of 36 pb −1. The transverse momentum balance in dijet and γ/Z+jets events is used to measure the jet energy response in the CMS detector, as well as the transverse momentum resolution. The results are presented for three different methods to reconstruct jets: a calorimeter-based approach, the "Jet-Plus-Track" approach, which improves the measurement of calorimeter jets by exploiting the associated tracks, and the "Particle Flow" approach, which attempts to reconstruct individually each particle in the event, prior to the jet clustering, based on information from all relevant subdetectors. KEYWORDS: Si microstrip and pad detectors; Calorimeter methods; Detector modelling and simulations I (interaction of radiation with matter, interaction of photons with matter, interaction of hadrons with matter, etc) ARXIV EPRINT: 1107.4277

The ripple transport of fast (suprathermal) ions and electrons in tokamaks is investigated. This transport, which is due to the drift motion of particles blocked in the ripple of a magnetic field, is of the convective type for particles with an energy exceeding some value ℰd. For ions in real tokamaks, this energy region may be close to the bulk of ions having thermal energy. Kinetic equations for the particle distribution function are derived, the ripple drift motion through the magnetic surfaces being taken into account. In the low-energy (diffusive) limit, the results agree with the well-known ones. For more energetic particles convective transport dominates. In particular, a replacement, through the ripple channel, of fast electrons from the hot periphery is possible, resulting there in a considerable rise of the distribution function tail. The increase in the ripple depth from the chamber centre to the periphery is very important; it causes collisionless adiabatic capture of particles by ripples, which are held there, then drift and finally escape from the plasma. This process leads to the formation of a special type of trajectories (‘open’ trajectories) , which directly connect the chamber walls with the central position of the plasma column and may bring about considerable particle and energy losses. In addition, this phenomenon leads to a depletion of the particle distribution function.

The CMS collaborationAbstract: A measurement of the exclusive two-photon production of muon pairs in proton-proton collisions at √ s = 7 TeV, pp → pµ + µ − p, is reported using data corresponding to an integrated luminosity of 40 pb −1 . For muon pairs with invariant mass greater than 11.5 GeV, transverse momentum p T (µ) > 4 GeV and pseudorapidity |η(µ)| < 2.1, a fit to the dimuon p T (µ + µ − ) distribution results in a measured cross section of σ(p → pµ + µ − p) = 3.38 +0.58 −0.55 (stat.) ± 0.16 (syst.) ± 0.14 (lumi.) pb, consistent with the theoretical prediction evaluated with the event generator Lpair. The ratio to the predicted cross section is 0.83 +0.14 −0.13 (stat.) ± 0.04 (syst.) ± 0.03 (lumi.). The characteristic distributions of the muon pairs produced via γγ fusion, such as the muon acoplanarity, the muon pair invariant mass and transverse momentum agree with those from the theory.

We present an experimental and theoretical study of carrier-envelope-phase (CEP) effects on the population transfer between two bound atomic states interacting with pulses consisting of many cycles. Using intense radio-frequency pulse with Rabi frequency of the order of the atomic transition frequency, we investigate the influence of the CEP on the control of phase-dependent multiphoton transitions between the Zeeman sublevels of the ground state of 87 Rb. Our scheme has no limitation on the duration of the pulses. Extending the CEP control to longer pulses creates interesting possibilities to generate pulses with accuracy that is better than the period of optical oscillations.

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