2,023 research outputs found

    Kinstate intervention in ethnic conflicts : Albania and Turkey compared

    Get PDF
    Albania and Turkey did not act in overtly irredentist ways towards their ethnic brethren in neighboring states after the end of communism. Why, nonetheless, did Albania facilitate the increase of ethnic conflict in Kosovo and Macedonia, while Turkey did not, with respect to the Turks of Bulgaria? I argue that kin-states undergoing transition are more prone to intervene in external conflicts than states that are not, regardless of the salience of minority demands in the host-state. The transition weakens the institutions of the kin-state. Experiencing limited institutional constraints, self-seeking state officials create alliances with secessionist and autonomist movements across borders alongside their own ideological, clan-based and particularistic interests. Such alliances are often utilized to advance radical domestic agendas. Unlike in Albania's transition environment, in Turkey there were no emerging elites that could potentially form alliances and use external movements to legitimize their own domestic existence or claims

    Quantum Storage of Photonic Entanglement in a Crystal

    Full text link
    Entanglement is the fundamental characteristic of quantum physics. Large experimental efforts are devoted to harness entanglement between various physical systems. In particular, entanglement between light and material systems is interesting due to their prospective roles as "flying" and stationary qubits in future quantum information technologies, such as quantum repeaters and quantum networks. Here we report the first demonstration of entanglement between a photon at telecommunication wavelength and a single collective atomic excitation stored in a crystal. One photon from an energy-time entangled pair is mapped onto a crystal and then released into a well-defined spatial mode after a predetermined storage time. The other photon is at telecommunication wavelength and is sent directly through a 50 m fiber link to an analyzer. Successful transfer of entanglement to the crystal and back is proven by a violation of the Clauser-Horne-Shimony-Holt (CHSH) inequality by almost three standard deviations (S=2.64+/-0.23). These results represent an important step towards quantum communication technologies based on solid-state devices. In particular, our resources pave the way for building efficient multiplexed quantum repeaters for long-distance quantum networks.Comment: 5 pages, 3 figures + supplementary information; fixed typo in ref. [36

    First Measurement of Coherent Elastic Neutrino-Nucleus Scattering on Argon

    Full text link
    We report the first measurement of coherent elastic neutrino-nucleus scattering (\cevns) on argon using a liquid argon detector at the Oak Ridge National Laboratory Spallation Neutron Source. Two independent analyses prefer \cevns over the background-only null hypothesis with greater than 3σ3\sigma significance. The measured cross section, averaged over the incident neutrino flux, is (2.2 ±\pm 0.7) ×\times1039^{-39} cm2^2 -- consistent with the standard model prediction. The neutron-number dependence of this result, together with that from our previous measurement on CsI, confirms the existence of the \cevns process and provides improved constraints on non-standard neutrino interactions.Comment: 8 pages, 5 figures with 2 pages, 6 figures supplementary material V3: fixes to figs 3,4 V4: fix typo in table 1, V5: replaced missing appendix, V6: fix Eq 1, new fig 3, V7 final version, updated with final revision

    ‘Stumbling through’? Relationship-based social work practice in austere times

    Get PDF
    In recent times relationship-based practice has become a familiar term in social work practice and education. Despite its widespread adoption, how relationship-based practice is understood varies widely. Drawing on contemporary conceptualisations of the child and family and individuals as psychosocial subjects experiencing social suffering, this paper explores how current social work practice can be understood in the context of neoliberalism and austerity. Setting these ideas in an historical context helps to inform our understanding as to why social work seems to be the focus of sustained political discontent and scrutiny, making it difficult to retain a balanced relationship-based professional stance. Contemporary responses to the current challenges of everyday practice are outlined and the contribution of psychodynamic and systemic ideas to promoting relationship-based practice is explored. The paper concludes by considering how the concept of social systems as defences against anxiety can inform our understanding of the resistance amongst practitioners to relationship-based practice and emphasises the importance of reflective spaces and places for developing and maintaining integrated, mature relational approaches to practice which impact on practice at both the individual casework and social structural level

    Evidence for Isospin Violation and Measurement of CPCP Asymmetries in BK(892)γB \to K^{\ast}(892) \gamma

    Full text link
    We report the first evidence for isospin violation in BKγB \to K^* \gamma and the first measurement of difference of CPCP asymmetries between B+K+γB^+ \to K^{*+} \gamma and B0K0γB^0 \to K^{*0} \gamma. This analysis is based on the data sample containing 772×106BBˉ772 \times 10^6 B\bar{B} pairs that was collected with the Belle detector at the KEKB energy-asymmetric e+ee^+ e^- collider. We find evidence for the isospin violation with a significance of 3.1σ\sigma, Δ0+=(+6.2±1.5(stat.)±0.6(syst.)±1.2(f+/f00))\Delta_{0+} = (+6.2 \pm 1.5 ({\rm stat.}) \pm 0.6 ({\rm syst.}) \pm 1.2 (f_{+-}/f_{00}))\%, where the third uncertainty is due to the uncertainty on the fraction of B+BB^+B^- to B0Bˉ0B^0\bar{B}^0 production in Υ(4S)\Upsilon(4S) decays. The measured value is consistent with predictions of the SM. The result for the difference of CPCP asymmetries is ΔACP=(+2.4±2.8(stat.)±0.5(syst.))\Delta A_{CP} = (+2.4 \pm 2.8({\rm stat.}) \pm 0.5({\rm syst.}))\%, consistent with zero. The measured branching fractions and CPCP asymmetries for charged and neutral BB meson decays are the most precise to date. We also calculate the ratio of branching fractions of B0K0γB^0 \to K^{*0} \gamma to Bs0ϕγB_s^0 \to \phi \gamma.Comment: 11 pages, 7 figures. shown at FPCP2017. accepted by PR

    Measurement of the τ\tau lepton polarization and R(D)R(D^*) in the decay BˉDτνˉτ\bar{B} \rightarrow D^* \tau^- \bar{\nu}_\tau with one-prong hadronic τ\tau decays at Belle

    Get PDF
    With the full data sample of 772×106772 \times 10^6 BBˉB{\bar B} pairs recorded by the Belle detector at the KEKB electron-positron collider, the decay BˉDτνˉτ\bar{B} \rightarrow D^* \tau^- \bar{\nu}_\tau is studied with the hadronic τ\tau decays τπντ\tau^- \rightarrow \pi^- \nu_\tau and τρντ\tau^- \rightarrow \rho^- \nu_\tau. The τ\tau polarization Pτ(D)P_\tau(D^*) in two-body hadronic τ\tau decays is measured, as well as the ratio of the branching fractions R(D)=B(BˉDτνˉτ)/B(BˉDνˉ)R(D^{*}) = \mathcal{B}(\bar {B} \rightarrow D^* \tau^- \bar{\nu}_\tau) / \mathcal{B}(\bar{B} \rightarrow D^* \ell^- \bar{\nu}_\ell), where \ell^- denotes an electron or a muon. Our results, Pτ(D)=0.38±0.51(stat)0.16+0.21(syst)P_\tau(D^*) = -0.38 \pm 0.51 {\rm (stat)} ^{+0.21}_{-0.16} {\rm (syst)} and R(D)=0.270±0.035(stat)0.025+0.028(syst)R(D^*) = 0.270 \pm 0.035{\rm (stat)} ^{+0.028}_{-0.025}{\rm (syst)}, are consistent with the theoretical predictions of the Standard Model. The polarization values of Pτ(D)>+0.5P_\tau(D^*) > +0.5 are excluded at the 90\% confidence level.Comment: 17 pages, 11 figures, submitted to Physical Review

    Photonic quantum state transfer between a cold atomic gas and a crystal

    Full text link
    Interfacing fundamentally different quantum systems is key to build future hybrid quantum networks. Such heterogeneous networks offer superior capabilities compared to their homogeneous counterparts as they merge individual advantages of disparate quantum nodes in a single network architecture. However, only very few investigations on optical hybrid-interconnections have been carried out due to the high fundamental and technological challenges, which involve e.g. wavelength and bandwidth matching of the interfacing photons. Here we report the first optical quantum interconnection between two disparate matter quantum systems with photon storage capabilities. We show that a quantum state can be faithfully transferred between a cold atomic ensemble and a rare-earth doped crystal via a single photon at telecommunication wavelength, using cascaded quantum frequency conversion. We first demonstrate that quantum correlations between a photon and a single collective spin excitation in the cold atomic ensemble can be transferred onto the solid-state system. We also show that single-photon time-bin qubits generated in the cold atomic ensemble can be converted, stored and retrieved from the crystal with a conditional qubit fidelity of more than 85%85\%. Our results open prospects to optically connect quantum nodes with different capabilities and represent an important step towards the realization of large-scale hybrid quantum networks

    Search for the 00^{--} Glueball in Υ(1S)\Upsilon(1S) and Υ(2S)\Upsilon(2S) decays

    Full text link
    We report the first search for the JPC=0J^{PC}=0^{--} glueball in Υ(1S)\Upsilon(1S) and Υ(2S)\Upsilon(2S) decays with data samples of (102±2)(102\pm2) million and (158±4)(158\pm4) million events, respectively, collected with the Belle detector. No significant signals are observed in any of the proposed production modes, and the 90\% credibility level upper limits on their branching fractions in Υ(1S)\Upsilon(1S) and Υ(2S)\Upsilon(2S) decays are obtained. The inclusive branching fractions of the Υ(1S)\Upsilon(1S) and Υ(2S)\Upsilon(2S) decays into final states with a χc1\chi_{c1} are measured to be \BR(\Upsilon(1S)\to \chi_{c1}+ anything) = (1.90\pm 0.43(stat.)\pm 0.14(syst.))\times 10^{-4} with an improved precision over prior measurements and \BR(\Upsilon(2S)\to \chi_{c1}+ anything) = (2.24\pm 0.44(stat.)\pm 0.20(syst.))\times 10^{-4} for the first time.Comment: 19 pages, 17 figures, Fig.10b was polished, but all the results unchanged. Paper was published in PR
    corecore