Production of positronium chloride: A study of the charge exchange reaction between Ps and Cl−^{-}

We present cross sections for the formation of positronium chloride (PsCl) in its ground state from the charge exchange between positronium (Ps) and chloride (Cl$^-$) in the range of 10 meV - 100 eV Ps energy. We have used theoretical models based on the first Born approximation in its three-body formulation. We simulated the collisions between Ps and Cl$^-$ using ab-initio methods at both mean-field and correlated levels extrapolated to the complete basis set limit. We have investigated Ps excited states up to ${n=4}$. The results suggest that the channel Ps(${n=2}$) is of particular interest for the production of PsCl in the ground state, and shows that an accurate treatment of the electronic correlation leads to a significant change in the global shape of the PsCl production cross section with respect to the mean-field level.Comment: 13 Pages, 7 Figures, 3 Table

Measurements of the Higgs boson production and decay rates and constraints on its couplings from a combined ATLAS and CMS analysis of the LHC pp collision data at root s=7 and 8 TeV

70 pages plus author lists + cover page (104 pages total), 32 figures, 22 tables, submitted to JHEP. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HIGG-2015-07/ and at http://cms-results.web.cern.ch/cms-results/public-results/publications/HIG-15-002/Combined ATLAS and CMS measurements of the Higgs boson production and decay rates, as well as constraints on its couplings to vector bosons and fermions, are presented. The combination is based on the analysis of five production processes, namely gluon fusion, vector boson fusion, and associated production with a $W$ or a $Z$ boson or a pair of top quarks, and of the six decay modes $H \to ZZ, WW$, $\gamma\gamma, \tau\tau, bb$, and $\mu\mu$. All results are reported assuming a value of 125.09 GeV for the Higgs boson mass, the result of the combined measurement by the ATLAS and CMS experiments. The analysis uses the CERN LHC proton--proton collision data recorded by the ATLAS and CMS experiments in 2011 and 2012, corresponding to integrated luminosities per experiment of approximately 5 fb$^{-1}$ at $\sqrt{s}=7$ TeV and 20 fb$^{-1}$ at $\sqrt{s} = 8$ TeV. The Higgs boson production and decay rates measured by the two experiments are combined within the context of three generic parameterisations: two based on cross sections and branching fractions, and one on ratios of coupling modifiers. Several interpretations of the measurements with more model-dependent parameterisations are also given. The combined signal yield relative to the Standard Model prediction is measured to be 1.09 $\pm$ 0.11. The combined measurements lead to observed significances for the vector boson fusion production process and for the $H \to \tau\tau$ decay of $5.4$ and $5.5$ standard deviations, respectively. The data are consistent with the Standard Model predictions for all parameterisations considered.Peer reviewe

High-harmonic generation in a quantum electron gas trapped in a nonparabolic and anisotropic well

An effective self-consistent model is derived and used to study the dynamics of an electron gas confined in a nonparabolic and anisotropic quantum well. This approach is based on the equations of quantum hydrodynamics, which incorporate quantum and nonlinear effects in an approximate fashion. The effective model consists of a set of six coupled differential equations (dynamical system) for the electric dipole and the size of the electron gas. Using this model we show that: (i) high harmonic generation is related to the appearance of chaos in the phase space, as attested to by related Poincare sections; (ii) higher order harmonics can be excited efficiently and with relatively weak driving fields by making use of chirped electromagnetic waves

The Multifaceted Nature of “Food Diversity” as a Life-Related Legal Value

none1siInternational and Italian legal literature has dedicated considerable worthy research to food law in relation to questions such as food security, quality and typicality (along with the related topics of indication and guarantee of origin), the right to food, as well as food sovereignty. The same cannot be said, however, in the matter of food diversity as a significant value in law, with the exception of a few recent research initiatives underway. The genetic diversity of the living sources of food is a value that is certainly implicated in food diversity, but, as this paper seeks to show, the latter is a value of synthesis that, despite encompassing animal, vegetable and microbial biodiversity, is not exhausted only within it. What seems useful therefore is an endeavour to investigate the problem of food diversity from a broader perspective so as to delineate some frames of reference. Food diversity can be said to be a synthesis of multiple diversities. It is a value system where numerous legal values of primary importance under constitutional protection converge and are contained: environment/biodiversity, territorial autonomy and differentiation, landscape, cultural heritage, human health, personal and religious freedom, and the educational choices of the family. The strengths of these basic value aggregate organically, conferring to food diversity a role of absolute primary importance in law. As this paper proposes, recognizing cultural diversity as a complex, systemic and life-related legal value, that is, as a “condensation” of the normative energy originating from the combination of multiple constitutionally fundamental legal values that are bound up with the supreme value of life in its differing scales, which in their turn are inextricably interrelated, permits the attribution to food diversity of a much stronger (respecting the situation to date) “resistance” in law against purely economic interests.Library of Congress Control Number: 2018933578. The collective book reflects on the issues concerning, on the one hand, the difficulty in feeding an ever- increasing world population and, on the other hand, the need to build new productive systems able to protect the planet from overexploitation. The concept of “food diversity” is a synthesis of diversities: biodiversity of ecological sources of food supply; socio territorial diversity; and cultural diversity of food traditions. In keeping with this transdisciplinary perspective, the book collects a large number of contributions that examine, firstly the relationships between agrobiodiversity, rural sustainable systems and food diversity; and secondly, the issues concerning typicality (food specialties/food identities), rural development and territorial communities. Lastly, it explores legal questions concerning the regulations aiming to protect both the food diversity and the right to food, in the light of the political, economic and social implications related to the problem of feeding the world population, while at the same time respecting local communities’ rights, especially in the developing countries. The book collects the works of legal scholars, agroecologists, historians and sociologists from around the globe. ****** Il volume è stato segnalato dalla Netherlands Quarterly of Human Rights 2018, Vol. 36(3) 236. Esso è inoltre presente in numerose biblioteche internazionali, tra cui quella della Stanford University: https://searchworks.stanford.edu/view/12658601 .noneM. MONTEDUROMonteduro, M

Measurement of the WW boson polarisation in ttˉt\bar{t} events from pppp collisions at s\sqrt{s} = 8 TeV in the lepton+jets channel with ATLAS

See paper for full list of authors - 42 pages in total, author list starting page 26, 10 figures, 5 tables, submitted to EPJC, All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/TOPQ-2016-02/International audienceThis paper presents a measurement of the polarisation of $W$ bosons from $t\bar{t}$ decays, reconstructed in events with one high-p_{\mbox{T}} lepton and at least four jets. Data from $pp$ collisions at the LHC were collected at $\sqrt{s}$ = 8 TeV and correspond to an integrated luminosity of 20.2 fb$^{-1}$. The angle $\theta^{*}$ between the $b$-quark from the top quark decay and a direct $W$ boson decay product in the $W$ boson rest frame is sensitive to the $W$ boson polarisation. Two different $W$ decay products are used as polarisation analysers: the charged lepton and the down-type quark for the leptonically and hadronically decaying $W$ boson, respectively. The most precise measurement of the $W$ boson polarisation via the distribution of $\cos{\theta^{*}}$ is obtained using the leptonic analyser and events in which at least two of the jets are tagged as $b$-quark jets. The fitted fractions of longitudinal, left- and right-handed polarisation states are $F_{\mathrm{0}}= 0.709 \pm {0.019}$, $F_{\mathrm{L}}= 0.299 \pm {0.015}$ and $F_{\mathrm{R}}= -0.008 \pm {0.014}$, and are the most precisely measured $W$ boson polarisation fractions to date. Limits on anomalous couplings of the $Wtb$ vertex are set

Measurements of top-quark pair differential cross-sections in the eμe\mu channel in pppp collisions at s=13\sqrt{s} = 13 TeV using the ATLAS detector

See paper for full list of authors - 43 pages in total, author list starting page 26, 5 figures, 5 tables, submitted to EPJC, all figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/TOPQ-2016-04/International audienceThis article presents measurements of $t\bar{t}$ differential cross-sections in a fiducial phase-space region, using an integrated luminosity of 3.2 fb$^{-1}$ of proton--proton data at a centre-of-mass energy of $\sqrt{s} = 13$ TeV recorded by the ATLAS experiment at the LHC in 2015. Differential cross-sections are measured as a function of the transverse momentum and absolute rapidity of the top quark, and of the transverse momentum, absolute rapidity and invariant mass of the $t\bar{t}$ system. The $t\bar{t}$ events are selected by requiring one electron and one muon of opposite electric charge, and at least two jets, one of which must be tagged as containing a $b$-hadron. The measured differential cross-sections are compared to predictions of next-to-leading order generators matched to parton showers and the measurements are found to be consistent with all models within the experimental uncertainties with the exception of the POWHEG-Box + HERWIG++ predictions, which differ significantly from the data in both the transverse momentum of the top quark and the mass of the $t\bar{t}$ system

Search for dark matter in association with a Higgs boson decaying to bb-quarks in pppp collisions at s=13\sqrt{s} = 13 TeV with the ATLAS detector

See paper for full list of authors - 36 pages in total, author list starting page 20, 4 figures, 2 tables, submitted to Phys. Lett. B. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/EXOT-2015-23/International audienceA search for dark matter pair production in association with a Higgs boson decaying to a pair of bottom quarks is presented, using 3.2 $fb^{-1}$ of $pp$ collisions at a centre-of-mass energy of 13 TeV collected by the ATLAS detector at the LHC. The decay of the Higgs boson is reconstructed as a high-momentum $b\bar{b}$ system with either a pair of small-radius jets, or a single large-radius jet with substructure. The observed data are found to be consistent with the expected backgrounds. Results are interpreted using a simplified model with a $Z'$ gauge boson mediating the interaction between dark matter and the Standard Model as well as a two-Higgs-doublet model containing an additional $Z'$ boson which decays to a Standard Model Higgs boson and a new pseudoscalar Higgs boson, the latter decaying into a pair of dark matter particles

Measurement of the bb‾b\overline{b} dijet cross section in pppp collisions at s=7\sqrt{s} = 7 TeV with the ATLAS detector

See paper for full list of authors - 19 pages plus author list ( 36 pages total), 8 figures, 3 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2013-03/International audienceThe dijet production cross section for jets containing a $b$-hadron ($b$-jets) has been measured in proton-proton collisions with a centre-of-mass energy of $\sqrt{s} = 7$ TeV, using the ATLAS detector at the LHC. The data used correspond to an integrated luminosity of 4.2 fb$^{-1}$. The cross section is measured for events with two identified $b$-jets with a transverse momentum $p_T > 20$ GeV and a minimum separation in the $\eta$-$\phi$ plane of $\Delta R = 0.4$. At least one of the jets in the event is required to have $p_T > 270$ GeV. The cross section is measured differentially as a function of dijet invariant mass, dijet transverse momentum, boost of the dijet system, and the rapidity difference, azimuthal angle and angular distance between the $b$-jets. The results are compared to different predictions of leading order and next-to-leading order perturbative quantum chromodynamics matrix elements supplemented with models for parton-showers and hadronization