2,535 research outputs found

    Rare kaon decays in SUSY with non-universal A terms

    Full text link
    We study the rare kaon decays in the framework of general SUSY models. Unlike the results in the literature, we find the contributions from the gluino exchange to the branching ratio of K+π+ννˉK^+\to \pi^+ \nu \bar{\nu} can reach the central value (1.5×1010\sim 1.5 \times 10^{-10}) of the new E787 data while the predicted value of standard model is less than 101010^{-10}. We also find that the same effects also enhance the decays of KLπ0ννˉK_{L}\to \pi^0 \nu \bar{\nu}, KLπ0e+eK_L\to\pi^0e^{+} e^{-} and KLμ+μK_L\to\mu^+ \mu^-.Comment: 9 pages, references added, revised version to appear in J. Phys.

    Comment on "Quantum key distribution without alternative measurements"

    Full text link
    In a recent paper [A. Cabello, Phys. Rev. A 61, 052312 (2000)], a quantum key distribution protocol based on entanglement swapping was proposed. However, in this comment, it is shown that this protocol is insecure if Eve use a special strategy to attack.Comment: 2 Pages, 1 Figur

    Solvable Systems of Linear Differential Equations

    Full text link
    The asymptotic iteration method (AIM) is an iterative technique used to find exact and approximate solutions to second-order linear differential equations. In this work, we employed AIM to solve systems of two first-order linear differential equations. The termination criteria of AIM will be re-examined and the whole theory is re-worked in order to fit this new application. As a result of our investigation, an interesting connection between the solution of linear systems and the solution of Riccati equations is established. Further, new classes of exactly solvable systems of linear differential equations with variable coefficients are obtained. The method discussed allow to construct many solvable classes through a simple procedure.Comment: 13 page

    BU10038 as a safe opioid analgesic with fewer side-effects after systemic and intrathecal administration in primates

    Get PDF
    © 2019 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.Background: The marked increase in mis-use of prescription opioids has greatly affected our society. One potential solution is to develop improved analgesics which have agonist action at both mu opioid peptide (MOP) and nociceptin/orphanin FQ peptide (NOP) receptors. BU10038 is a recently identified bifunctional MOP/NOP partial agonist. The aim of this study was to determine the functional profile of systemic or spinal delivery of BU10038 in primates after acute and chronic administration. Methods: A series of behavioural and physiological assays have been established specifically to reflect the therapeutic (analgesia) and side-effects (abuse potential, respiratory depression, itch, physical dependence, and tolerance) of opioid analgesics in rhesus monkeys. Results: After systemic administration, BU10038 (0.001–0.01 mg kg −1 ) dose-dependently produced long-lasting antinociceptive and antihypersensitive effects. Unlike the MOP agonist oxycodone, BU10038 lacked reinforcing effects (i.e. little or no abuse liability), and BU10038 did not compromise the physiological functions of primates including respiration, cardiovascular activities, and body temperature at antinociceptive doses and a 10–30-fold higher dose (0.01–0.1 mg kg −1 ). After intrathecal administration, BU10038 (3 μg) exerted morphine-comparable antinociception and antihypersensitivity without itch scratching responses. Unlike morphine, BU10038 did not cause the development of physical dependence and tolerance after repeated and chronic administration. Conclusions: These in vivo findings demonstrate the translational potential of bifunctional MOP/NOP receptor agonists such as BU10038 as a safe, non-addictive analgesic with fewer side-effects in primates. This study strongly supports that bifunctional MOP/NOP agonists may provide improved analgesics and an alternative solution for the ongoing prescription opioid crisis.Peer reviewedFinal Published versio

    Probabilistic quantum cloning via Greenberger-Horne-Zeilinger states

    Full text link
    We propose a probabilistic quantum cloning scheme using Greenberger-Horne-Zeilinger states, Bell basis measurements, single-qubit unitary operations and generalized measurements, all of which are within the reach of current technology. Compared to another possible scheme via Tele-CNOT gate [D. Gottesman and I. L. Chuang, Nature 402, 390 (1999)], the present scheme may be used in experiment to clone the states of one particle to those of two different particles with higher probability and less GHZ resources.Comment: 8 Pages, 4 Figures, final version to appear in PR

    A Unified Quantum NOT Gate

    Full text link
    We study the feasibility of implementing a quantum NOT gate (approximate) when the quantum state lies between two latitudes on the Bloch's sphere and present an analytical formula for the optimized 1-to-MM quantum NOT gate. Our result generalizes previous results concerning quantum NOT gate for a quantum state distributed uniformly on the whole Bloch sphere as well as the phase covariant quantum state. We have also shown that such 1-to-MM optimized NOT gate can be implemented using a sequential generation scheme via matrix product states (MPS)

    Repeat-Until-Success quantum computing using stationary and flying qubits

    Full text link
    We introduce an architecture for robust and scalable quantum computation using both stationary qubits (e.g. single photon sources made out of trapped atoms, molecules, ions, quantum dots, or defect centers in solids) and flying qubits (e.g. photons). Our scheme solves some of the most pressing problems in existing non-hybrid proposals, which include the difficulty of scaling conventional stationary qubit approaches, and the lack of practical means for storing single photons in linear optics setups. We combine elements of two previous proposals for distributed quantum computing, namely the efficient photon-loss tolerant build up of cluster states by Barrett and Kok [Phys. Rev. A 71, 060310(R) (2005)] with the idea of Repeat-Until-Success (RUS) quantum computing by Lim et al. [Phys. Rev. Lett. 95, 030505 (2005)]. This idea can be used to perform eventually deterministic two-qubit logic gates on spatially separated stationary qubits via photon pair measurements. Under non-ideal conditions, where photon loss is a possibility, the resulting gates can still be used to build graph states for one-way quantum computing. In this paper, we describe the RUS method, present possible experimental realizations, and analyse the generation of graph states.Comment: 14 pages, 7 figures, minor changes, references and a discussion on the effect of photon dark counts adde

    SUSY QCD impact on top-pair production associated with a Z0Z^0-boson at a photon-photon collider

    Full text link
    The top-pair production in association with a Z0Z^0-boson at a photon-photon collider is an important process in probing the coupling between top-quarks and vector boson and discovering the signature of possible new physics. We describe the impact of the complete supersymmetric QCD(SQCD) next-to-leading order(NLO) radiative corrections on this process at a polarized or unpolarized photon collider, and make a comparison between the effects of the SQCD and the standard model(SM) QCD. We investigate the dependence of the lowest-order(LO) and QCD NLO corrected cross sections in both the SM and minimal supersymmetric standard model(MSSM) on colliding energy s\sqrt{s} in different polarized photon collision modes. The LO, SM NLO and SQCD NLO corrected distributions of the invariant mass of ttˉt\bar t-pair and the transverse momenta of final Z0Z^0-boson are presented. Our numerical results show that the pure SQCD effects in \ggttz process can be more significant in the +++ + polarized photon collision mode than in other collision modes, and the relative SQCD radiative correction in unpolarized photon collision mode varies from 32.09% to 1.89-1.89 % when s\sqrt{s} goes up from 500GeV500 GeV to 1.5TeV1.5 TeV.Comment: 22 pages and 13 figure

    Cosmic rays from Leptonic Dark Matter

    Full text link
    If dark matter possesses a lepton number, it is natural to expect the dark-matter annihilation and/or decay mainly produces the standard model leptons, while negligible amount of the antiproton is produced. To illustrate such a simple idea, we consider a scenario that a right-handed sneutrino dark matter decays into the standard model particles through tiny R-parity violating interactions. Interestingly enough, charged leptons as well as neutrinos are directly produced, and they can lead to a sharp peak in the predicted positron fraction. Moreover, the decay of the right-handed sneutrino also generates diffuse continuum gamma rays which may account for the excess observed by EGRET, while the primary antiproton flux can be suppressed. Those predictions on the cosmic-ray fluxes of the positrons, gamma rays and antiprotons will be tested by the PAMELA and FGST observatories.Comment: 21 pages, 4 figures, 2 tables, updated plots including PAMELA dat
    corecore