6,189 research outputs found

    Bell inequality for pairs of particle-number-superselection-rule restricted states

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    Proposals for Bell inequality tests on systems restricted by superselection rules often require operations that are difficult to implement in practice. In this paper, we derive a new Bell inequality, where pairs of states are used to by-pass the superselection rule. In particular, we focus on mode entanglement of an arbitrary number of massive particles and show that our Bell inequality detects the entanglement in the pair when other inequalities fail. However, as the number of particles in the system increases, the violation of our Bell inequality decreases due to the restriction in the measurement space caused by the superselection rule. This Bell test can be implemented using techniques that are routinely used in current experiments.Comment: 9 pages, 6 figures; v2 is the published versio

    ¿El tamaño y la orientación del grupo intruso afecta a la distancia de iniciación al vuelo en aves?

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    Wildlife managers use flight initiation distance (FID), the distance animals flee an approaching predator, to determine set back distances to minimize human impacts on wildlife. FID is typically estimated by a single person; this study examined the effects of intruder number and orientation on FID. Three different group size treatments (solitary person, two people side–by–side, two people one–behind–the–other) were applied to Pied Currawongs (Strepera graculina) and to Crimson Rosellas (Platycerus elegans). Rosellas flushed at significantly greater distances when approached by two people compared to a single person. This effect was not seen in currawongs. Intruder orientation did not influence the FID of either species. Results suggest that intruder number should be better integrated into estimates of set back distance to manage human visitation around sensitive species.Los gestores de la fauna utilizan la distancia de iniciación al vuelo (FID), la distancia a la que los animales huyen cuando se les acerca un depredador, para determinar las distancias de respuesta a fin de minimizar el impacto humano en la fauna. La FID es estimada típicamente por una sola persona; este estudio examinó los efectos del número y de la orientación del intruso en la FID. Se aplicaron tres tratamientos distintos de tamaño del grupo (persona solitaria, dos personas una al lado de la otra, dos personas una detras de la otra) a currawongs cálidos (Strepera graculina) y a pericos elegantes (Platycerus elegans). Los pericos elegantes huían a distancias perceptiblemente mayores cuando se le acercaban dos personas que cuando se le acercaba una sola. Este efecto no fue observado en los currawongs pálidos. La orientación del intruso no influenció en la FID de ninguna especie. Los resultados sugieren que el número de intrusos debería ser considerado en las estimaciones de las distancias de respuesta, para poder gestionar las visitas de personas cerca de especies sensibles

    First determination of the CPCP content of Dπ+ππ+πD \to \pi^+\pi^-\pi^+\pi^- and updated determination of the CPCP contents of Dπ+ππ0D \to \pi^+\pi^-\pi^0 and DK+Kπ0D \to K^+K^-\pi^0

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    Quantum-correlated ψ(3770)DDˉ\psi(3770) \to D\bar{D} decays collected by the CLEO-c experiment are used to perform a first measurement of F+4πF_+^{4\pi}, the fractional CPCP-even content of the self-conjugate decay Dπ+ππ+πD \to \pi^+\pi^-\pi^+\pi^-, obtaining a value of 0.737±0.0280.737 \pm 0.028. An important input to the measurement comes from the use of DKS0π+πD \to K^0_{\rm S}\pi^+\pi^- and DKL0π+πD \to K^0_{\rm L}\pi^+\pi^- decays to tag the signal mode. This same technique is applied to the channels Dπ+ππ0D \to\pi^+\pi^-\pi^0 and DK+Kπ0D \to K^+K^-\pi^0, yielding F+πππ0=1.014±0.045±0.022F_+^{\pi\pi\pi^0} = 1.014 \pm 0.045 \pm 0.022 and F+KKπ0=0.734±0.106±0.054F_+^{KK\pi^0} = 0.734 \pm 0.106 \pm 0.054, where the first uncertainty is statistical and the second systematic. These measurements are consistent with those of an earlier analysis, based on CPCP-eigenstate tags, and can be combined to give values of F+πππ0=0.973±0.017F_+^{\pi\pi\pi^0} = 0.973 \pm 0.017 and F+KKπ0=0.732±0.055F_+^{KK\pi^0} = 0.732 \pm 0.055. The results will enable the three modes to be included in a model-independent manner in measurements of the unitarity triangle angle γ\gamma using BDKB^\mp \to DK^\mp decays, and in time-dependent studies of CPCP violation and mixing in the DDˉD\bar{D} system.Comment: Minor revisions following journal acceptanc

    Coefficient Functions and Open Charm Production in Deep Inelastic Scattering

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    It is shown that the problem of double counting in open charm production in DIS can be solved by using the expression for DIS coefficient functions in terms of 2PI diagramsComment: 11 pages, REVTeX, no figure

    Branching of the Falkner-Skan solutions for λ < 0

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    The Falkner-Skan equation f'" + ff" + λ(1 - f'^2) = 0, f(0) = f'(0) = 0, is discussed for λ < 0. Two types of problems, one with f'(∞) = 1 and another with f'(∞) = -1, are considered. For λ = 0- a close relation between these two types is found. For λ < -1 both types of problem allow multiple solutions which may be distinguished by an integer N denoting the number of zeros of f' - 1. The numerical results indicate that the solution branches with f'(∞) = 1 and those with f'(∞) = -1 tend towards a common limit curve as N increases indefinitely. Finally a periodic solution, existing for λ < -1, is presented.

    First determination of the CP content of D->pi+pi-pi0 and D->K+K-pi0

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    Quantum-correlated psi(3770)->DDbar decays collected by the CLEO-c experiment are used to perform first measurements of F+, the fractional CP-even content of the self-conjugate decays D->pi+pi-pi0 and D->K+K-pi0. Values of 0.968 +/- 0.017 +/- 0.006 and 0.731 +/- 0.058 +/- 0.021 are obtained for pi+pi-pi0 and K+K-pi0, respectively. It is demonstrated how modes of this sort can be cleanly included in measurements of the unitarity triangle angle gamma using B+/- -> D K+/- decays. The high CP-even content of D -> pi+pi-pi0, in particular, makes this a promising mode for improving the precision on gamma.Comment: 18 pages, 4 figures, submitted to Phys. Lett.

    KLF9 and JNK3 Interact to Suppress Axon Regeneration in the Adult CNS

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    Neurons in the adult mammalian CNS decrease in intrinsic axon growth capacity during development in concert with changes in Krüppel-like transcription factors (KLFs). KLFs regulate axon growth in CNS neurons including retinal ganglion cells (RGCs). Here, we found that knock-down of KLF9, an axon growth suppressor that is normally upregulated 250-fold in RGC development, promotes long-distance optic nerve regeneration in adult rats of both sexes. We identified a novel binding partner, MAPK10/JNK3 kinase, and found that JNK3 (c-Jun N-terminal kinase 3) is critical for KLF9\u27s axon-growth-suppressive activity. Interfering with a JNK3-binding domain or mutating two newly discovered serine phosphorylation acceptor sites, Ser106 and Ser110, effectively abolished KLF9\u27s neurite growth suppression in vitro and promoted axon regeneration in vivo. These findings demonstrate a novel, physiologic role for the interaction of KLF9 and JNK3 in regenerative failure in the optic nerve and suggest new therapeutic strategies to promote axon regeneration in the adult CNS
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