On the q-deformation of the NJL model

Using a q-deformed fermionic algebra we perform explicitly a deformation of the Nambu-Jona-Lasinio (NJL) Hamiltonian. In the Bogoliubov-Valatin approach we obtain the deformed version of the functional for the total energy, which is minimized to obtain the corresponding gap equation. The breaking of chiral symmetry and its restoration in the limit $q \to 0$ are then discussed.Comment: 5 eps figure

Entanglement universality of two-qubit X-states

We demonstrate that for every two-qubit state there is a X-counterpart, i.e., a corresponding two-qubit X-state of same spectrum and entanglement, as measured by concurrence, negativity or relative entropy of entanglement. By parametrizing the set of two-qubit X-states and a family of unitary transformations that preserve the sparse structure of a two-qubit X-state density matrix, we obtain the parametric form of a unitary transformation that converts arbitrary two-qubit states into their X-counterparts. Moreover, we provide a semi-analytic prescription on how to set the parameters of this unitary transformation in order to preserve concurrence or negativity. We also explicitly construct a set of X-state density matrices, parametrized by their purity and concurrence, whose elements are in one-to-one correspondence with the points of the concurrence versus purity (CP) diagram for generic two-qubit states.Comment: 24 pages, 6 figures. v2 includes new references and minor changes (accepted version

Seed Dispersal Of Attalea Phalerata (palmae) By Crested Caracaras (caracara Plancus) In The Pantanal And A Review Of Frugivory By Raptors

We observed Crested caracaras (Caracara plancus) consuming and dispersing fruits of the palm Attalea phalerata at Pantanal, Brazil. We reviewed the literature of seed dispersal by raptors and suggest that raptors may affect seed dispersal by three different paths: secondary seed dispersal by preying on frugivorous birds, primary seed dispersal of ornithocoric fruits and primary seed dispersal of large, lipid-rich fruits. The latter path may be an important long-distance seed dispersal mechanism for large seeds.122133135Brown, L.H., Amadon, D., (1968) Eagles, Hawks & Falcons of the World, , Wellfleet Press, New JerseyBrown, L.H., Urban, E.K., Newman, K., (1982) The Birds of Africa, , Academic Press, LondonBuskirk, W.H., Lechner, M., Frugivory by swallow-tailed kites in Costa Rica (1978) Auk, 95, pp. 767-768Carciofi, A.C., Estudos sobre nutrição de psitacídeos em vida livre: O exemplo da Arara-Azul (Anodorhynchus hyacinthinus) (2002) Ecologia e conservação de psitacídeos no Brasil, , M. 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John Wiley & Sons: 119-144Fragoso, J.M.V., Silvius, K.M., Correa, J.A., Long-distance seed dispersal by tapirs increases seed survival and aggregates tropical trees (2003) Ecology, 84, pp. 1998-2006Gerhardt, R.P., Gerhardt, D.M., Vasquez, M.A., Food delivered to nests of Swallow-tailed Kites in Tikal National Park, Guatemala (2004) Condor, 106, pp. 177-181Guedes, N. M. R. and L. H. Harper (1995). Hyacinth macaws in the Pantanal. The Large Macaws. J. Abramson, B. L. Speer and J. B. Thomsen. 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