abstract

The validity of non-perturbative methods is questioned. The concept of relative space is introduced.

abstract

A new description of unconstrained degrees of freedom for the gravitational field introduced in [6] has been applied to the description of perturbed initial data from the Reissner–Nordström solution. When this solution describes a black hole \((m \gt q)\) we can perform a generic fully nonlinear perturbation of initial data outside an apparent horizon in such a way that this horizon is an extremal two-surface in four-dimensional spacetime. A simple consequence of the considerations in: J. Jezierski, Classical Quantum Gravity 11, 1055 (1994) leads to the following theorem: Let \(\mit \Sigma \) be an asymptotically flat spacelike surface which is nonsingular outside an external two-surface \(S_{\rm min}\) (which is extremal as two-surface imbedded in spacetime) then \(16\pi m^2_{\rm ADM} \geq A\), where \(m_{\rm ADM}\) denotes the A.D.M. mass of perturbed data (around Reissner–Nordström solution) on \(\mit \Sigma \) and \(A\) is an area of the apparent horizon \(S_{\rm min}\).

abstract

This work presents a simple way of incorporating quark degrees of freedom (spin, charge and colour) into the classical string model. We introduce the model and derive from it the classical equations of motion.

abstract

High energy proton and antiproton scattering on nuclei is considered. Inclusive spectra \(p^{\pm }A \to p^{\pm } + X\) are discussed in the framework of constituent quark models. Predictions of the models with colour excitations of constituent quarks are examined. These models in which fragmentation into leading hadrons depends only on the total colour of the constituents in the intermediate state are excluded by the experimental data.

abstract

The mass splittings of hyperons including the isospin splittings are calculated with \(O(m^2_{\rm s}\) and \(O(m_{\rm s}{\mit \Delta }m)\) accuracy respectively within the semi-bosonized SU(3)-Nambu–Jona-Lasinio model. The pattern of the isospin splittings is not spoiled by the terms of the order \(O(m_{\rm s}{\mit \Delta }m)\), and both splittings between the different isospin multiplets and within the same multiplet are well reproduced for acceptable values of \(m_{\rm s}\) and \({\mit \Delta }m\).

abstract

We survey at the general level, and in a rather wide and historical context, some less known mathematical details of various mean free path statistics in nuclear emulsion as applied to relativistic projectile fragmentations. A number of comments are provided on Feller’s paradox, ordered, censored, and truncated statistics, Erlang and Poisson observers of nuclear emulsion. All these are related to the statistical approaches used about a decade ago at Berkeley Bevalac for anomalons, some of which should be considered as standard methods for mean free paths’ estimators of relativistic heavy ions in emulsion.

abstract

We study the neutron superfluidity in the inner crust of a neutron star where a gas of unbound nucleons coexists with a lattice of neutron rich nuclei, using a Wigner–Seitz approximation and a well tested nuclear force. We found a neutron pairing energy gap which is generally larger outside the nuclear region. In order to clarify the relevance of our results we evaluate the pinning energy of vortices to nuclei and compare it with previous calculations.

abstract

Models for internal annihilation of quarks as a mechanism for baryon–antibaryon \((B_1 \overline {B}_2)\) production at low energy \(p\bar p\) scattering are discussed. The results in form of branching ratios for different \((B_1 \overline {B}_2)\) channels are compared with existing data either at a fixed center of mass energy \(\sqrt {s}\) or at the same excess energy \(\varepsilon = \sqrt {s} - m_{B_1}- m_{B_2}\). We find reasonable agreement with experimental data provided the internal quark interaction is of vector type. These results are contrasted to q  annihilation proceeding via an effective instanton interaction or in the context of Nambu–Jona-Lasinio type of models.