Bonn Group Research Articles

Opening up research in social sciences

The Open Research Area (ORA) for Social Sciences is an international initiative that provides social science research funding and support. It was founded in 2010 by members of the Bonn Group and based on agreement by European social science funding bodies The Agence Nationale de la Recherche (ANR), France, the Deutsche Forschungsgemeinschaft (DFG), Germany, the Economic and Social Research Council (ESRC), UK, and the Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO), the Netherlands. The Social Sciences and Humanities Research Council (SSHRC), Canada, later joined, as well as the Japan Society for the Promotion of Science (JSPS) as an associate member. ORA facilitates collaborative social sciences research by bringing together researchers from participating countries. Researchers from the partner countries who fulfil the eligibility criteria of their national funding organisation apply to the ORA office handling the year's applications and Japanese researchers submit their applications to JSPS Tokyo. ORA accepts applications from all areas of the social sciences and there is a key focus on supporting young researchers at the beginning of their careers, helping them to extend the reach of their work and network on an international scale. Ultimately, ORA exists to drive forward high-quality research and strengthen international collaboration in social sciences research. So far, five rounds of ORA have been successfully completed, with more than 60 international collaborative proposals funded across diverse social sciences fields, including political science, economics, empirical social science, psychology, geography, urban planning and education science.

Opening up research in social sciences

The Open Research Area (ORA) for Social Sciences is an international initiative that provides social science research funding and support. It was founded in 2010 by members of the Bonn Group and based on agreement by European social science funding bodies The Agence Nationale de la Recherche (ANR), France, the Deutsche Forschungsgemeinschaft (DFG), Germany, the Economic and Social Research Council (ESRC), UK, and the Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO), the Netherlands. The Social Sciences and Humanities Research Council (SSHRC), Canada, later joined, as well as the Japan Society for the Promotion of Science (JSPS) as an associate member. ORA facilitates collaborative social sciences research by bringing together researchers from participating countries. Researchers from the partner countries who fulfil the eligibility criteria of their national funding organisation apply to the ORA office handling the year's applications and Japanese researchers submit their applications to JSPS Tokyo. ORA accepts applications from all areas of the social sciences and there is a key focus on supporting young researchers at the beginning of their careers, helping them to extend the reach of their work and network on an international scale. Ultimately, ORA exists to drive forward high-quality research and strengthen international collaboration in social sciences research. So far, five rounds of ORA have been successfully completed, with more than 60 international collaborative proposals funded across diverse social sciences fields, including political science, economics, empirical social science, psychology, geography, urban planning and education science.

“A Trivial and Unimportant Ally”? Britain and the West German-Soviet Treaty Negotiations, 1970

ABSTRACTThis analysis explores British perceptions and roles regarding the negotiation of the West German-Soviet Moscow treaty of 1970. Whilst supportive of West German Ostpolitik, Britain has received a very marginal role in the historiography of the treaty. By exploring the consultation process in the so-called Bonn Group of the United States, Britain, France, and West Germany, this exegesis explains that Britain played a leading role in building consensus and forming schemes to resolve the issue of the treatment of Quadripartite Rights and Responsibilities concerning Berlin in the Moscow treaty package. As background, this essay also explains the policies of the Harold Wilson’s Labour government and Edward Heath’s Conservative government regarding European détente in Europe, including West German Ostpolitik.

H3 and He3 calculations without angular momentum decomposition

Results for the three nucleon (3N) bound state carried out using the "three dimensional" (3D) formalism are presented. In this approach calculations are performed without the use of angular momentum decomposition and instead rely directly on the 3D degrees of freedom of the nucleons. In this paper, for the first time, 3D results for $^{3}$He bound state with the inclusion of the screened Coulomb potential are compared to $^{3}$H calculations. Additionally, using these results, matrix elements of simple current operators related to the description of beta decay of the triton are given. All computations are carried out using the first generation of NNLO two nucleon (2N) and 3N forces from the Bochum - Bonn group.

Study of Deuteron with Modified Screen Coulomb (Yakawa) Potential

In this paper the Schrodinger equation was solved with modified screen coulomb (yukawa) potential and the one pion exchange potential. A mathematical method has been presented. Analytical solution of the Schrödinger equation with modified yukawa potential has been calculated. Then the ground state energy of deuteron was determined. We have used the second potential as a perturbation potential and found the energy shift of grand state energy of deuteron. Then we have used numerical method and solving the Schrödinger equation numerically. Finally, the results were compared with Bonn group and the HQCD.

Electromagnetic Transitions of Hyperons in a Relativistic Quark Model

The relativistically covariant constituent quark model developed by the Bonn group is used to compute the EM form factors of strange baryons. We present form-factor results for the ground-state and some excited hyperons. The computed magnetic moments agree well with the experimental values and the magnetic form factors follow a dipole $Q^2$ dependence.

Electric and magnetic form factors of strange baryons

Predictions for the electromagnetic form factors of the $\Lambda$ , $\Sigma$ and $\Xi$ hyperons are presented. The numerical calculations are performed within the framework of the fully relativistic constituent-quark model developed by the Bonn group. The computed magnetic moments compare favorably with the experimentally known values. Most magnetic form factors G M (Q 2) can be parameterized in terms of a dipole with cutoff masses ranging from 0.79 to 1.14 GeV.

Neutron-star properties from modern meson-exchange potential models

In this work we calculate the total mass, radius, moment of inertia and surface gravitational redshift for neutron stars using various equations of state (EOS). The latter are derived from the recent meson-exchange potential models of the Bonn group, and we derive both a non-relativistic and a relativistic EOS. Of importance here is the fact that relativistic Brueckner-Hartree-Fock calculations for symmetric nuclear matter meet the empirical data, which are not reproduced by non-relativistic calculations. Relativistic effects are known to be important at high densities, giving an increased repulsion. This leads to a stiffer EOS compared to the EOS derived with a nonrelativistic approach. Both the non-relativistic and the relativistic EOS yield values for moment of inertia and redshifts in agreement with the accepted values. The relativistic EOS yields however too large mass and radius. The implications are discussed.

Separable Representation of N Scattering Amplitudes

Separable representations of the S and P wave amplitudes are presented for the pion incident energy-range in the laboratory system: TL=0-400 MeV. We make separable potentials in rank one or two form and in one or multi-channel form, depending on the eigenstates. The relationship between the form factor of Pn potential and the 11NN vertex form factor in the one-pion-exchange potential is seriously taken into account. The potentials are made by fitting the two empirical partial wave amplitudes by Koch and Pietarinen and by Arndt, Ford and Roper. in a separable form with respect to the initial and final relative momenta. This makes the three-body calculation considerably tractable and transparent. Therefore the separable form of the potentials are very significant for the study of· the TCNN system. So far the separable TCN potentials have been presented in fitting the TCN phase shifts by various groups. 4 >.s> Among all, the Pu potential is relatively complicated. This eigenstate has the nucleon pole as well as the Roper resonance and requires the separable representation in a rank two form at least. Furthermore the form factor of the separable potential should relate with the TCNN vertex form factor appearing in the one-pion-exchange potential for nuclear forces. So far, however, this interrela­ tion is not so seriously taken into account. In this paper we put the strong condition that the form factor for the nucleon pole part of the Pu potential is the same with the TCNN vertex form factor for the one-pion-exchange potential. This should provide more realistic condition for the off-shell structure of the potential than the so far presented versions. The form factor of the TCNN vertex has been studied by various groups, since Ueda and Green introduced it into the one-boson-exchange potential in 1967. 6 > They used the size parameter A in the dipole parametrization as large as A=2-3 GeV. Although Bonn group made the search of a smaller value to be consistent with the values from subhadronic models: A~0.7-0.8 GeV, they find A~1.3 GeV. 7 > More recently Ueda has proposed that the one-pion-exchange with the TCNN form factor with A=2-3 GeV is interpreted as the sum of the one-pion-exchange with a soft form factor of A~0.9 GeV and the 1=1, r=o- part of the correlated three-pion­ exchange.2>.s>-lo) The latter is effectively represented by an isovector and pseudo­

W-matrix method for the representation of the scattering T matrix: Analytical example.

The original W-matrix approach, introduced recently by the Bonn group, represents the T matrix by a rank-one separable term. The method is exactly half on shell, but a nonzero remainder R occurs fully off shell. For potentials for which the scattering phase shift has a zero, the remainder can be non-negligible, even for energies far from the zero. We present expressions for W and R in terms of the scattering K matrix for the case that the potential is separable of finite rank. We show that the rank of R is one less than the rank of the potential. Then, for a rank-two analytical S-wave example of the potential, which is designed to produce a zero in the phase shift, we examine numerically the fully off-shell properties of the W method. We find pathologies at both negative and positive energies, in that the remainder R gives a significant off-shell contribution even far from the singularity.

Coupling channel model of the NN system with virtual Δ-isobars in a nonrelativistic OBE model

A nonrelativistic model of nucleon-nucleon interaction below the pion production threshold has been developed with virtual Δ-isobars taken into account explicitly in the coupled channel formalism. The diagonal and transition potentials are one-boson-exchange ones. The potentials in nucleon-nucleon channels are similar to those of the Bonn group while the transition and diagonal potentials in NΔ and ΔΔ channels are obtained from those in NN channels by relating coupling constants at relevant vertices within the quark model. The experimental nucleon-nucleon scattering phase shifts and the deuteron properties are described reasonably well. The amount of ΔΔ component in the deuteron is about 0.4%.

Off-shell effects from meson exchange in the nuclear optical potential.

First-order Kerman-McManus-Thaler nuclear optical potentials for intermediate energy protons are constructed from realistic meson-exchange models of the nucleon-nucleon interaction including off-shell effects. At 200 MeV the full model developed by the Bonn group is employed, while at 500 MeV a simplified version with delta resonance inelasticity is used. The resulting off-shell effects on the nuclear scattering spin observables are found to be substantial.

N[formula omitted] annihilation at rest into πππ and K[formula omitted]π in the 3P0-model

Selection rules off pp-annihilation at rest into πσ, KK∗ and KK∗ are studied in the A3-model or the 3P0-model with assumptions that ϱ is ππ and K∗ (K∗) is Kπ(Kπ) resonant state. Selection rules and isospin mixing effects in pp-annihilation at rest into ππ and KK are also studied in the A2-model with meson exchange potential of Bonn group and Paris group. Comparisons with experimental data suggest that NN-annihilation into mesons is indeed dominated by An (n = 2,3…) models.

Gaussian parametrization of a meson-theoreticalN-N potential for microscopic nuclear-structure calculations

The radial dependencies of anr-space version of the meson-theoretical nucleon-nucleon potential of the Bonn group (OBEPR) are expressed through a set of Gaussians. First results for the three-nucleon system are given.

Differential cross sections for proton compton scattering at incident photon energies between 900 MeV and 1150 MeV

Differential cross sections of proton Compton scattering have been measured in the angular range between 50° and 130° at incident photon energies from 900 MeV to 1150 MeV. A sharp dip in the angular distribution found by a Bonn group at 110° in the photon energy region around 900 MeV is not observed in the present measurement. A new dip-bump structure is found at photon energies above 1050 MeV, which is similar to that for pion-nucleon scattering.

Neo-Humboldtian semantics in perspective: ‘Sprache und Gemeinshaft’

The series 'Sprache und Gemeinschaft' (for titles, etc., cf. below, p. io8) marks a further stage in the amplification of the linguistic theory of the Bonn group around Leo Weisgerber.' The diversity of talents it brings together also marks the extent of the group's influence. It includes pupils of the Miinster Germanist Jost Trier, and grammarians like Hennig Brinkmann and Hans Glinz, whose most distinctive gifts should not necessarily be identified with Weisgerber's characteristic methods. The movement has developed largely out of intellectual impulses native to Germany, Trier's and Weisgerber's roots being in the idealist intellectual climate of the 1920'S. There are, however, parallels and fruitful points of contrast with movements in the English-speaking world General Semantics, the Whorf hypothesis, and even Gestalt psychology (itself a transplant from Germany, and in its heyday a rallying point for resistance to the emerging behaviourist establishment in America). The movement has seen various names applied to it, ranging from Funke's 'Neo-Romanticism' to Basilius's 'Neo-Humboldtian Ethnolinguistics' (abbreviated by Ivi6, none too flatteringly, to 'Humboldtism'). Its own preferred terms are Inhaltsforschung or inhaltbezogene Grammatik (Sprachforschung) 'content research' or 'content-oriented grammar (linguistics)'. If Weisgerber has always insisted that an account of 'content' was a characteristic part of linguistic description and did not have to be integrated into it at an advanced stage, this was out of no fondness for talking about 'meaning' (Bedeutung). Ever since his earliest polemics (I925 ff.), reflecting a somewhat nebulous crisis in semantics, he has insisted on the term Inhalt, embodying this in a more integrated and 'energetic' model than that inspired by the simpliste view that 'meaning' is something a word 'has' (as men have souls and machines might have ghosts). During a middle period (I936-I949), Weisgerber devoted himself to an intensive study of the word deutsch. He tried to show this as creating first an

Small vases from Euboean workshops

Perhaps the most popular vase shape in Euboea in the fourth century was the lidded lekanis. A number of specimens, decorated with floral motives on the lid and simple leaves or linear patterns on the receptacles, may be seen in BSA lv, pls. 54–57 passim. They show considerable variety in the shape of the knobs and in the treatment of the handles, but the receptacles remain fundamentally the same. Akin to these are little bowls of similar shape, lidded, but without handles. Such are the vases of a kernos of unknown provenience in Athens with a vaguely anthropomorphic central handle consisting of a long loop surmounted by a moulded head and with small arm-like projections recalling those of a herm (Plate 1, 1). The lids of three of the four little vases are preserved, the two nearest the handle having horizontal rims, while the two outer vases both had lids with rims turning vertically down, as is shown by the one extant lid and by the flanges on both the receptacles. The knobs of the two lids with horizontal rims are of a shape similar to the stemmed foot of a cup or dish; the surviving lid with down-turned rim has a ring like the footring of a stemless cup to serve as a knob. Each kind of knob, stemmed or stemless, functioned as a foot when the lid was set upside down on the table and became a dish. The low footring knobs were not unknown in Athens, but they were commoner in Euboea. One was noticed in BSA lv. 212, no. 8 on a lid, not figured, belonging to the Bonn group of floral black-figure, which is undoubtedly of Euboean, and very probably of Chalcidian manufacture. We shall see more of them later on.

Low Energy Charged Meson Photoproduction

We describe an experiment on the photoproduction of charged π+ mesons from hydrogen at 50° in the laboratory and at gamma-ray energies between 160 and 200 MeV. The results of the present experiment, together with recent results at higher energies reported by the Bonn group, are in good agreement with the fixed-momentum dispersion relation predictions of Chew, Goldberger, Low and Nambu. Following the suggestion of Baldin, the comparison of the data and theory was performed in a manner such that the momentum transfer to the nucleon was fixed and equal to that occurring at threshold, thereby eliminating certain unknowns in the theory.