18 research outputs found

    On the cubic interactions of massive and partially-massless higher spins in (A)dS

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    Cubic interactions of massive and partially-massless totally-symmetric higher-spin fields in any constant-curvature background of dimension greater than three are investigated. Making use of the ambient-space formalism, the consistency condition for the traceless and transverse parts of the parity-invariant interactions is recast into a system of partial differential equations. The latter can be explicitly solved for given s_1-s_2-s_3 couplings and the 2-2-2 and 3-3-2 examples are provided in detail for general choices of the masses. On the other hand, the general solutions for the interactions involving massive and massless fields are expressed in a compact form as generating functions of all the consistent couplings. The St\"uckelberg formulation of the cubic interactions as well as their massless limits are also analyzed.Comment: 42 pages, 2 tables, LaTex. Comments on two-derivative couplings involving partially-massless spin-2 fields added, typos corrected, references added. v2: final version to appear in JHEP. v3: formulae (3.4) and (3.9) correcte

    Elliptic flow of charged particles in Pb-Pb collisions at 2.76 TeV

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    We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at 2.76 TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region (|η\eta|<0.8) and transverse momentum range 0.2< pTp_{\rm T}< 5.0 GeV/cc. The elliptic flow signal v2_2, measured using the 4-particle correlation method, averaged over transverse momentum and pseudorapidity is 0.087 ±\pm 0.002 (stat) ±\pm 0.004 (syst) in the 40-50% centrality class. The differential elliptic flow v2(pT)_2(p_{\rm T}) reaches a maximum of 0.2 near pTp_{\rm T} = 3 GeV/cc. Compared to RHIC Au-Au collisions at 200 GeV, the elliptic flow increases by about 30%. Some hydrodynamic model predictions which include viscous corrections are in agreement with the observed increase.Comment: 10 pages, 4 captioned figures, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/389

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∌99% of the euchromatic genome and is accurate to an error rate of ∌1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    Involvement of the recoverin C-terminal segment in recognition of the target enzyme rhodopsin kinase

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    NCS (neuronal Ca 2+ sensor) proteins belong to a family of calmodulin-related EF-hand Ca 2+-binding proteins which, in spite of a high degree of structural similarity, are able to selectively recognize and regulate individual effector enzymes in a Ca 2+-dependent manner. NCS proteins vary at their C-termini, which could therefore serve as structural control elements providing specific functions such as target recognition or Ca 2+ sensitivity. Recoverin, an NCS protein operating in vision, regulates the activity of rhodopsin kinase, GRK1, in a Ca 2+-dependent manner. In the present study, we investigated a series of recoverin forms that were mutated at the C-terminus. Using pull-down assays, surface plasmon resonance spectroscopy and rhodopsin phosphorylation assays, we demonstrated that truncation of recoverin at the C-terminus significantly reduced the affinity of recoverin for rhodopsin kinase. Site-directed mutagenesis of single amino acids in combination with structural analysis and computational modelling of the recoverin-kinase complex provided insight into the protein-protein interface between the kinase and the C-terminus of recoverin. Based on these results we suggest that Phe 3 from the N-terminal helix of rhodopsin kinase and Lys 192 from the C-terminal segment of recoverin form a cation-\u3c0 interaction pair which is essential for target recognition by recoverin. Taken together, the results of the present study reveal a novel rhodopsin-kinase-binding site within the C-terminal region of recoverin, and highlights its significance for target recognition and regulation

    Coherent single charged pion production by neutrinos

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    We report on a measurement of coherent single charged pion production in neutrino-nucleus scattering. The analysis is based on data taken with the CHARM II detector in beams of muon-neutrinos and -antineutrinos. The event numbers amount to N(ÎŒ-π) = 748 and N(ÎŒ+π) = 631. Cross sections and their dependence on the neutrino energy are determined. The results are in agreement with the predictions of models based on the PCAC hypothesis

    Search for Îœ_ÎŒ → Îœ_τ oscillation

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    The fine granularity of the CHARM-II detector has been exploited to search, in the CERN-SPS wide band neutrino beam, for quasi-elastic Μτ interactions followed by the decay τ → πΜτ. Since the sampling thickness of the target calorimeter corresponds to 1/9 of an interaction length, these events appear in the detector as a single track followed by a hadronic shower. The study of the “single pion” events is used to set limits on the ΜΌ → Μτ oscillation parameters. The maximum sensitivity to the mixing angle Ξ is reached for Δm^2 = 50 eV2 allowing to exclude values of sin^2(2Ξ) greater than 6.4 × 10^−3 at 90% CL

    Search For Nu(mu)-]nu(tau) Oscillation

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    The fine granularity of the CHARM-II detector has been exploited to search, in the CERN-SPS wide band neutrino beam, for quasi-elastic nu(tau) interactions followed by the decay tau --> pinu(tau). Since the sampling thickness of the target calorimeter corresponds to approximately 1/9 of an interaction length, these events appear in the detector as a single track followed by a hadronic shower. The study of the ''single pion'' events is used to set limits on the nu(mu) --> nu(tau) oscillation parameters. The maximum sensitivity to the mixing angle theta is reached for DELTAm2 = 50 eV2 allowing to exclude values of sin2 20 greater than 6.4 x 10(-3) at 90% CL
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