5,310 research outputs found

    Omega_{ccc} production via fragmentation at LHC

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    In the framework of the leading order of perturbative QCD and the nonrelativistic quark-diquark model of baryons we have obtained fragmentation function for c-quark to split into Omega_{ccc} baryon. It is shown that at LHC one can expect 3.5 10^3 events with Omega_{ccc} at p_t>5 GeV/c and -1<y<1 per year.Comment: LaTex, 5 pages and 2 figures. Talk presented at XIV Workshop on High Energy Physics and Quantum Field Theory, Moscow, May 27 - June 4, 199

    One-loop counterterms in the Yang-Mills theory with gauge invariant ghost field Lagrangian

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    One-loop calculations of renormalization constants in the model with gauge invariant ghost field Lagrangian are performed. It is shown that the model is asymptotically free and the renormalization constants satisfy the same equation as in the ordinary Yang-Mills theory.Comment: 11 pages, 6 figure

    Critical temperature and Ginzburg-Landau equation for a trapped Fermi gas

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    We discuss a superfluid phase transition in a trapped neutral-atom Fermi gas. We consider the case where the critical temperature greatly exceeds the spacing between the trap levels and derive the corresponding Ginzburg-Landau equation. The latter turns out to be analogous to the equation for the condensate wave function in a trapped Bose gas. The analysis of its solution provides us with the value of the critical temperature TcT_{c} and with the spatial and temperature dependence of the order parameter in the vicinity of the phase transition point.Comment: 6 pages, 1 figure, REVTeX. The figure improved. Misprints corrected. More discussion adde

    Topology by dissipation

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    Topological states of fermionic matter can be induced by means of a suitably engineered dissipative dynamics. Dissipation then does not occur as a perturbation, but rather as the main resource for many-body dynamics, providing a targeted cooling into a topological phase starting from an arbitrary initial state. We explore the concept of topological order in this setting, developing and applying a general theoretical framework based on the system density matrix which replaces the wave function appropriate for the discussion of Hamiltonian ground-state physics. We identify key analogies and differences to the more conventional Hamiltonian scenario. Differences mainly arise from the fact that the properties of the spectrum and of the state of the system are not as tightly related as in a Hamiltonian context. We provide a symmetry-based topological classification of bulk steady states and identify the classes that are achievable by means of quasi-local dissipative processes driving into superfluid paired states. We also explore the fate of the bulk-edge correspondence in the dissipative setting, and demonstrate the emergence of Majorana edge modes. We illustrate our findings in one- and two-dimensional models that are experimentally realistic in the context of cold atoms.Comment: 61 pages, 8 figure
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