Profiling a set of personality traits of text author: what our words reveal about us

Authorship profiling, i.e. revealing information about an unknown author by analyzing their text, is a task of growing importance. One of the most urgent problems of authorship profiling (AP) is selecting text parameters which may correlate to an author’s personality. Most researchers’ selection of these is not underpinned by any theory. This article proposes an approach to AP which applies neuroscience data. The aim of the study is to assess the probability of self-destructive behaviour of an individual via formal parameters of their texts. Here we have used the “Personality Corpus”, which consists of Russian-language texts. A set of correlations between scores on the Freiburg Personality Inventory scales that are known to be indicative of self-destructive behaviour (“Spontaneous Aggressiveness”, “Depressiveness”, “Emotional Lability”, and “Composedness”) and text variables (average sentence length, lexical diversity etc.) has been calculated. Further, a mathematical model which predicts the probability of self-destructive behaviour has been obtained

Impact of pion dynamics on nuclear shell structure

Spin-isospin response in exotic nuclear systems is investigated. It is found that in some nuclei excitations with pionic quantum numbers (0-, 1+, 2-, ...) appear at very low energies with large transition probabilities, which is an indication of the vicinity of the onset of pion condensation. As an example, 2- components of the spin-dipole resonance in 78-Ni and 132-Sn are considered. The existence of such modes points out to the necessity of taking into account their coupling to other elementary modes of excitation, e.g. single-quasiparticle ones. This coupling is introduced in the theory for the first time. Thereby, pion-exchange contribution to the nucleon-nucleon interaction is included in the relativistic framework beyond the Hartree-Fock approximation. Namely, classes of Feynman diagrams are selected according to their significance for nuclear spectroscopic characteristics, such as single-particle energies and strength functions, and included into the nucleonic self-energy in all orders of meson-exchange. As an illustration, the impact of these new contributions on the single-particle energies of 100-Sn is discussed.Comment: 5 pages, 3 figures; a Contribution to the Proceedings of the International Nuclear Physics Conference 'Nuclear Structure and Dynamics III

Nuclear response theory for spin-isospin excitations in a relativistic quasiparticle-phonon coupling framework

A new theoretical approach to spin-isospin excitations in open-shell nuclei is presented. The developed method is based on the relativistic meson-exchange nuclear Lagrangian of Quantum Hadrodynamics and extends the response theory for superfluid nuclear systems beyond relativistic quasiparticle random phase approximation in the proton-neutron channel (pn-RQRPA). The coupling between quasiparticle degrees of freedom and collective vibrations (phonons) introduces a time-dependent effective interaction, in addition to the exchange of pion and $\rho$-meson taken into account without retardation. The time-dependent contributions are treated in the resonant time-blocking approximation, in analogy to previously developed relativistic quasiparticle time blocking approximation (RQTBA) in the neutral (non-isospin-flip) channel. The new method is called proton-neutron RQTBA (pn-RQTBA) and applied to Gamow-Teller resonance in a chain of neutron-rich Nickel isotopes $^{68-78}$Ni. A strong fragmentation of the resonance along with quenching of the strength, as compared to pn-RQRPA, is obtained. Based on the calculated strength distribution, beta-decay half-lives of the considered isotopes are computed and compared to pn-RQRPA half-lives and to experimental data. It is shown that a considerable improvement of the half-life description is obtained in pn-RQTBA because of the spreading effects, which bring the lifetimes to a very good quantitative agreement with data.Comment: 14 pages, 11 figures. v3: convergence study added, other minor corrections and references added, version accepted for publication in The European Physical Journal A as part of the topical issue "Finite range effective interactions and associated many-body methods - A tribute to Daniel Gogny". The final publication is available at Springer via http://dx.doi.org/10.1140/epja/i2016-16205-

Microscopic description of nuclear vibrations: Relativistic QRPA and its extensions with quasiparticle-vibration coupling

The recent extensions of the covariant energy density functional theory with the quasiparticle-vibration coupling (QVC) are reviewed. Formulation of the Quasiparticle Random Phase Approximation (QRPA) in the relativistic framework is discussed. Self-consistent extensions of the relativistic QRPA imply the QVC which is implemented in two-body propagators in the nuclear medium. This provides fragmentation of the QRPA states describing the damping of the vibrational motion.Comment: Published in "50 Years of Nuclear BCS", edited by R. A. Broglia and V.G. Zelevinsky, World Scientific (2013

Quasiparticle-vibration coupling effects on nuclear transitions of astrophysical interest

The relativistic quasiparticle time-blocking approximation (RQTBA) is applied to the description of nuclear excitation modes of astrophysical interest. This method is based on the meson-nucleon Lagrangian and goes beyond the standard relativistic quasiparticle random-phase approximation (RQRPA) by treating the coupling between single quasiparticles and collective vibrations of the nucleus. We calculate electric dipole transitions and Gamow-Teller modes in the (p,n) direction in a few Sn isotopes and obtain the rates of (n,$\gamma$) reaction and $\beta^-$-decay processes, which govern the r-process nucleosynthesis, in a unified RQTBA framework. Gamow-Teller transitions in the (n,p) branch, which in principle can serve for the modeling of stellar evolution, are also investigated, and $^{90}$Zr is taken as a study case.Comment: 10 pages, 8 figures. Contribution to the proceedings of the Fifth Conference on Nuclei and Mesoscopic Physics (NMP17), East Lansing, USA, March 6-10, 201