Can translation invariant systems exhibit a Many-Body Localized phase?

This note is based on a talk by one of us, F. H., at the conference PSPDE II, Minho 2013. We review some of our recent works related to (the possibility of) Many-Body Localization in the absence of quenched disorder (in particular arXiv:1305.5127,arXiv:1308.6263,arXiv:1405.3279). In these works, we provide arguments why systems without quenched disorder can exhibit `asymptotic' localization, but not genuine localization.Comment: To appear in the Proceedings of the conference Particle systems and PDE's - II, held at the Center of Mathematics of the University of Minho in December 201

Synthesis and characterisation of lamellar ZnS nanosheets containing intercalated diamines

A solvothermal method has been used to preparehybrid inorganic-organic composites with a lamellar structure in which layers of wurtzite ZnS are separated by intercalated diamine molecules. A hybrid composite prepared with diethylenetriamine has been isolated and characterisedand its structure and properties compared with those of the composite prepared using ethylenediamine. Comparative structural and morphological studies of the two lamellar hybrid composites are described on the basis of powder XRD, electron and scanning probe microscopies and thermal analysis of the materials

Behavioral Inhibition and Attentional Control in Adolescents: Robust Relationships with Anxiety and Depression

Behavioral inhibition (BI) has been associated with the development of internalizing disorders in children and adolescents. It has further been shown that attentional control (AC) is negatively associated with internalizing problems. The combination of high BI and low AC may particularly lead to elevated symptomatology of internalizing behavior. This study broadens existing knowledge by investigating the additive and interacting effects of BI and AC on the various DSM-IV based internalizing dimensions. A sample of non-clinical adolescents (N = 1806, age M = 13.6 years), completed the Behavioral Inhibition System/Behavioral Activation System Scales (BIS/BAS), the attentional control subscale of the Adult Temperament Questionnaire (ATQ) and the Revised Child Anxiety and Depression Scale (RCADS). As expected, BI was positively, and AC was negatively related to internalizing dimensions, with stronger associations of BI than of AC with anxiety symptoms, and a stronger association of AC than of BI with depressive symptoms. AC moderated the association between BI and all measured internalizing dimensions (i.e., symptoms of generalized anxiety disorder, social phobia, separation anxiety disorder, panic disorder, obsessive–compulsive disorder, and major depressive disorder). Since high AC may reduce the impact of high BI on the generation of internalizing symptoms, an intervention focused on changing AC may have potential for prevention and treatment of internalizing disorders

First Observation of τ→3πηντ\tau\to 3\pi\eta\nu_{\tau} and τ→f1πντ\tau\to f_{1}\pi\nu_{\tau} Decays

We have observed new channels for $\tau$ decays with an $\eta$ in the final state. We study 3-prong tau decays, using the $\eta\to\gamma\gamma$ and \eta\to 3\piz decay modes and 1-prong decays with two \piz's using the $\eta\to\gamma\gamma$ channel. The measured branching fractions are \B(\tau^{-}\to \pi^{-}\pi^{-}\pi^{+}\eta\nu_{\tau}) =(3.4^{+0.6}_{-0.5}\pm0.6)\times10^{-4} and \B(\tau^{-}\to \pi^{-}2\piz\eta\nu_{\tau} =(1.4\pm0.6\pm0.3)\times10^{-4}. We observe clear evidence for $f_1\to\eta\pi\pi$ substructure and measure \B(\tau^{-}\to f_1\pi^{-}\nu_{\tau})=(5.8^{+1.4}_{-1.3}\pm1.8)\times10^{-4}. We have also searched for $\eta'(958)$ production and obtain 90% CL upper limits \B(\tau^{-}\to \pi^{-}\eta'\nu_\tau)<7.4\times10^{-5} and \B(\tau^{-}\to \pi^{-}\piz\eta'\nu_\tau)<8.0\times10^{-5}.Comment: 11 page postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN

Search for the Decays B^0 -> D^{(*)+} D^{(*)-}

Using the CLEO-II data set we have searched for the Cabibbo-suppressed decays B^0 -> D^{(*)+} D^{(*)-}. For the decay B^0 -> D^{*+} D^{*-}, we observe one candidate signal event, with an expected background of 0.022 +/- 0.011 events. This yield corresponds to a branching fraction of Br(B^0 -> D^{*+} D^{*-}) = (5.3^{+7.1}_{-3.7}(stat) +/- 1.0(syst)) x 10^{-4} and an upper limit of Br(B^0 -> D^{*+} D^{*-}) D^{*\pm} D^\mp and B^0 -> D^+ D^-, no significant excess of signal above the expected background level is seen, and we calculate the 90% CL upper limits on the branching fractions to be Br(B^0 -> D^{*\pm} D^\mp) D^+ D^-) < 1.2 x 10^{-3}.Comment: 12 page postscript file also available through http://w4.lns.cornell.edu/public/CLNS, submitted to Physical Review Letter

Hadronic Mass Moments in Inclusive Semileptonic B Meson Decays

We have measured the first and second moments of the hadronic mass-squared distribution in B -> X_c l nu, for P(lepton) > 1.5 GeV/c. We find <M_X^2 - M_D[Bar]^2> = 0.251 +- 0.066 GeV^2, )^2 > = 0.576 +- 0.170 GeV^4, where M_D[Bar] is the spin-averaged D meson mass. From that first moment and the first moment of the photon energy spectrum in b -> s gamma, we find the HQET parameter lambda_1 (MS[Bar], to order 1/M^3 and beta_0 alpha_s^2) to be -0.24 +- 0.11 GeV^2. Using these first moments and the B semileptonic width, and assuming parton-hadron duality, we obtain |V_cb| = 0.0404 +- 0.0013.Comment: 11 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS, submitted to PR

ΛΛˉ\Lambda\bar{\Lambda} Production in Two-Photon Interactions at CLEO

Using the CLEO detector at the Cornell $e^+e^-$ storage ring, CESR, we study the two-photon production of $\Lambda \bar{\Lambda}$, making the first observation of $\gamma \gamma \to \Lambda \bar{\Lambda}$. We present the cross-section for $\gamma \gamma \to \Lambda \bar{\Lambda}$ as a function of the $\gamma \gamma$ center of mass energy and compare it to that predicted by the quark-diquark model.Comment: 10 pages, postscript file also available through http://w4.lns.cornell.edu/public/CLN