Vom Majestätsverbrechen zum Terrorismus

CT

π\piNN coupling and two-pion photoproduction on the nucleon

Effects of non-resonant photoproductions arising from two different $\pi NN$ couplings are investigated in the $\gamma N\to\pi\pi N$ reaction. We find that the pseudoscalar (PS) $\pi NN$ coupling is generally preferable to the pseudovector (PV) $\pi NN$ coupling and particularly the total cross sections are successfully described by the model with the PS $\pi NN$ coupling. In order to see the difference between the two couplings, we also show the results of invariant mass spectra and helicity-dependent cross sections in various isospin channels calculated with the PS and PV couplings.Comment: 35 pages, 11 figures, minor changes and version to be published in Phys.Rev.

Compton Scattering by the Proton using a Large-Acceptance Arrangement

Compton scattering by the proton has been measured using the tagged-photon facility at MAMI (Mainz) and the large-acceptance arrangement LARA. The new data are interpreted in terms of dispersion theory based on the SAID-SM99K parameterization of photo-meson amplitudes. It is found that two-pion exchange in the t-channel is needed for a description of the data in the second resonance region. The data are well represented if this channel is modeled by a single pole with mass parameter m(sigma)=600 MeV. The asymptotic part of the spin dependent amplitude is found to be well represented by pi-0-exchange in the t-channel. A backward spin-polarizability of gamma(pi)=(-37.1+-0.6(stat+syst)+-3.0(model))x10^{-4}fm^4 has been determined from data of the first resonance region below 455 MeV. This value is in a good agreement with predictions of dispersion relations and chiral pertubation theory. From a subset of data between 280 and 360 MeV the resonance pion-photoproduction amplitudes were evaluated leading to a E2/M1 multipole ratio of the p-to-Delta radiative transition of EMR(340 MeV)=(-1.7+-0.4(stat+syst)+-0.2(model))%. It was found that this number is dependent on the parameterization of photo-meson amplitudes. With the MAID2K parameterization an E2/M1 multipole ratio of EMR(340 MeV)=(-2.0+-0.4(stat+syst)+-0.2(model))% is obtained

Subthreshold rho^0 photoproduction on 3He

A large reduction of the rho^0 mass in the nuclear medium is reported, inferred from dipion photoproduction spectra in the 1 GeV region, for the reaction 3He(gamma,pi+ pi-)X with a 10% duty factor tagged-photon beam and the TAGX multi-particle spectrometer. The energy range covered (800 < E(gamma) < 1120 MeV) lies mostly below the free rho^0 production threshold, a region which is believed sensitive to modifications of light vector-meson properties at nuclear-matter densities. The rho^0 masses extracted from the MC fitting of the data, m*(rho^0) = 642 +/- 40, 669 +/- 32, and 682 +/- 56 MeV/c^2 for E(gamma) in the 800-880, 880-960, and 960-1040 MeV regions respectively, are independently corroborated by a measured, assumption-free, kinematical observable. This mass shift, far exceeding current mean-field driven theoretical predictions, may be suggestive of rho^0 decay within the range of the nucleonic field.Comment: 40 pages, 13 figures, submitted to Phys. Rev.

The MentDis_ICF65+ study protocol: prevalence, 1-year incidence and symptom severity of mental disorders in the elderly and their relationship to impairment, functioning (ICF) and service utilisation.

Background: The EU currently lacks reliable data on the prevalence and incidence of mental disorders in older people. Despite the availability of several national and international epidemiological studies, the size and burden of mental disorders in the elderly remain unclear due to various reasons. Therefore, the aims of the MentDis_ICF65+ study are (1) to adapt existing assessment instruments, and (2) to collect data on the prevalence, the incidence, and the natural course and prognosis of mental disorders in the elderly. Method/design: Using a cross-sectional and prospective longitudinal design, this multi-centre study from six European countries and associated states (Germany, Great Britain, Israel, Italy, Spain, and Switzerland) is based on age-stratified, random samples of elderly people living in the community. The study program consists of three phases: (1) a methodological phase devoted primarily to the adaptation of age- and gender-specific assessment tools for older people (e.g., the Composite International Diagnostic Interview, CIDI) as well as psychometric evaluations including translation, back translation; (2) a baseline community study in all participating countries to assess the lifetime, 12 month and 1 month prevalence and comorbidity of mental disorders, including prior course, quality of life, health care utilization and helpseeking, impairments and participation and, (3) a 12 month follow-up of all baseline participants to monitor course and outcome as well as examine predictors. Discussion: The study is an essential step forward towards the further development and improvement of harmonised instruments for the assessment of mental disorders as well as the evaluation of activity impairment and participation in older adults. This study will also facilitate the comparison of cross-cultural results. These results will have bearing on mental health care in the EU and will offer a starting point for necessary structural changes to be initiated for mental health care policy at the level of mental health care politics

Photoproduction of scalar mesons on protons and nuclei

We study the photoproduction of scalar mesons close to the threshold of f_0(980) and a_0(980) using a unitary chiral model. Peaks for both resonances show up in the invariant mass distributions of pairs of pseudoscalar mesons. A discussion is made on the photoproduction of these resonances in nuclei, which can shed light on their nature, a subject of continuous debate.Comment: 25 pages, 9 figures, accepted for publication in Phys Rev

A three-talk model for shared decision making: multistage consultation process

© 2017 The Authors. Published by BMJ. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.1136/bmj.j4891Objectives To revise an existing three-talk model for learning how to achieve shared decision making, and to consult with relevant stakeholders to update and obtain wider engagement. Design Multistage consultation process. Setting Key informant group, communities of interest, and survey of clinical specialties. Participants 19 key informants, 153 member responses from multiple communities of interest, and 316 responses to an online survey from medically qualified clinicians from six specialties. Results After extended consultation over three iterations, we revised the three-talk model by making changes to one talk category, adding the need to elicit patient goals, providing a clear set of tasks for each talk category, and adding suggested scripts to illustrate each step. A new three-talk model of shared decision making is proposed, based on “team talk,” “option talk,” and “decision talk,” to depict a process of collaboration and deliberation. Team talk places emphasis on the need to provide support to patients when they are made aware of choices, and to elicit their goals as a means of guiding decision making processes. Option talk refers to the task of comparing alternatives, using risk communication principles. Decision talk refers to the task of arriving at decisions that reflect the informed preferences of patients, guided by the experience and expertise of health professionals. Conclusions The revised three-talk model of shared decision making depicts conversational steps, initiated by providing support when introducing options, followed by strategies to compare and discuss trade-offs, before deliberation based on informed preferences

Cold Accretion Disks and Lineless Quasars

The optical-UV continuum of quasars is broadly consistent with the emission from a geometrically thin optically thick accretion disk (AD). The AD produces the ionizing continuum which powers the broad and narrow emission lines. The maximum AD effective temperature is given by Teff=fmax(Mdot/M^2)^1/4, where M is the black hole mass, Mdot the accretion rate, and fmax is set by the black hole spin a_*. For a low enough value of Mdot/M^2 the AD may become too cold to produce ionizing photons. Such an object will form a lineless quasar. This occurs for a local blackbody (BB) AD with a luminosity Lopt=10^46 erg/s for M>3.6E9 Msun, when a_*=0, and for M>1.4E10 Msun, when a_*=0.998. Using the AD based Mdot, derived from M and Lopt, and the reverberation based M, derived from Lopt and the Hbeta FWHM, v, gives Teff \propto Lopt^-0.13v^-1.45. Thus, Teff is mostly set by v. Quasars with a local BB AD become lineless for v> 8,000 km/s, when a_*=0, and for v> 16,000 km/s, when a_*=0.998. Higher values of v are required if the AD is hotter than a local BB. The AD becoming non-ionizing may explain why line emitting quasars with v>10,000 km/s are rare. Weak low ionization lines may still be present if the X-ray continuum is luminous enough, and such objects may form a population of weak emission line quasars (WLQ). If correct, such WLQ should show a steeply falling SED at lambda<1000A. Such an SED was observed by Hryniewicz et al. in SDSS J094533.99+100950.1, a WLQ observed down to 570A, which is well modeled by a rather cold AD SED. UV spectroscopy of z~1-2 quasars is required to eliminate potential intervening Lyman limit absorption by the intergalactic medium (IGM), and to explore if the SEDs of lineless quasars and some additional WLQ are also well fit by a cold AD SED.Comment: Accepted for publication in MNRA

Photoproduction of pions and properties of baryon resonances from a Bonn-Gatchina partial wave analysis

Masses, widths and photocouplings of baryon resonances are determined in a coupled-channel partial wave analysis of a large variety of data. The Bonn-Gatchina partial wave formalism is extended to include a decomposition of t- and u-exchange amplitudes into individual partial waves. The multipole transition amplitudes for $\gamma p\to p\pi^0$ and $\gamma p\to n\pi^+$ are given and compared to results from other analyses.Comment: 18 pages, 14 figure