Volume 33, Issue 2
August 1989, pages 1-331
pp 1- August 1989 Rapid Communication
The role of combined electron-deuteron screening ind-d fusion in metals
We propose that thed-d fusion rate in palladium can be enhanced by the combined screening of the electrostatic interactions by the itinerant deuterons and the conduction electrons. The model assumes that, under certain conditions, deuterium exists as a D^{+} ion in palladium. The combined screening by electrons and the D^{+} ions (deuterons) is found to be more effective than that due to electrons alone. The calculated values of thed-d fusion rates, considering screening, for composition PdD at 300 K are 10^{−16} s^{−1} and 10^{−14} s^{−1} for D_{2}^{+} ion and D_{2} molecule respectively. These values lie in the range suggested by the recent electrochemical experiments.
pp 255-269 August 1989 Particle Physics
An analysis of the mass formulae forS- andP-wave mesons
Mass regularities forS- andP-wave mesons and relations between their masses are discussed. A detailed analysis is given forS-wave mesons which extends the investigations onP-wave mesons reported earlier. Masses for theS- andP-states of all interesting$$q\bar q$$-systems (including toponium states) are predicted. Partial understanding of the mass formulae is obtained within a general potential model approach. Scaling arguments are presented which support the empirical scaling behaviour found for the expectation values determining the spin-splittings in the potential picture.
pp 271-276 August 1989 Particle Physics
Variational calculation of the sine-Gordon effective potential
The Gaussian effective potential of the sine-Gordon model is calculated in 1+1 and 2+1 dimensions. Issues like renormalization, vacuum energy and stability of the vacuum are discussed in detail.
pp 277-287 August 1989 Particle Physics
Confinement of tensor gluons — a classical approach
We look at the confinement of tensor gluons (f_{μν}^{(c)} field) in a strong gravity background and find that the strong gravity provides a trap for the confinement of colour waves of selected frequencies. We assume that the tensorf_{μν}^{(c)} field (mediating quanta: tensor 2^{+}f-meson) satisfies Einstein-like equations with a cosmological constant. The colour field satisfy equations resembling Maxwell form of the linear theory of gravitation and see the effect off_{μν}^{(c)} field as playing the role of a medium having space dependent dielectric permeabilities. The solution of colour field equations resemble harmonic oscillator type wave functions with equispaced energy levels (no continuum) leading to confinement.
pp 289-296 August 1989 Particle Physics
A confinement model of hadron with its constituent quarks bound in a strong gravitational field is presented. The gravitational field plays the role of a medium having, as if, space dependent permeabilities from a fixed centre. The massless Dirac equation modified by the gravitational field is solved. The solution for the wavefunction of the quarks obtained shows the characteristic features of confinement, i.e., (i) wavefunction with higher energy states lying closer to the centre, (ii) equispaced energy levels without continuum, (iii) the quark orbits lying within a distance ∼ 10^{−14} cm, the characteristic radius of a typical hadron.
pp 297-313 August 1989 Condensed Matter Physics
A K Grover P L Paulose P Chaddah G Ravikumar
The existence of a remanent magnetization (M_{rem}) on switching off the field of a field cooled (FC) sample of a highT_{c} superconductor is often reported. It has recently been argued thatM_{rem} should equal the difference in FC and zero field cooled (ZFC) magnetizations (M_{FC} —M_{ZFC}) in hard superconductors and this has been demonstrated to hold in single crystals of YBCO at 4.2K over a limited range ofH values. We report the detailed magnetization measurements under various thermomagnetic histories (of whichM_{rem} is one special case) on two specimens of Nb, which show different extents of flux trapping. We find that there are in general three regions inH, T space, corresponding toM_{rem}+M_{ZFC}−M_{FC}=0,M_{rem}<(M_{FC}−M_{ZFC}) andM_{rem}>(M_{FC}−M_{ZFC}). At anyT, the equality holds forH<H_{c1}(T), and forH→H_{c2} (M_{FC}−M_{ZFC}) asymptotically vanishes and thereM_{rem}>(M_{FC}−M_{ZFC}). We show that there exists an intermediate region in all hard superconductors, whereM_{rem}<(M_{FC}−M_{ZFC}). The range over which this situation persists, however, depends on the degree of irreversibility in a sample. We can explain qualitatively all the history dependent magnetization data in terms of the critical state model. We point out an inconsistency in an earlier analysis to determineH_{c1}(T) from such data in YBCO. We also propose a new criterion for putting limits onH_{c1}(T) in hard superconductors.
pp 315-331 August 1989 Review Paper
Analytic structure of dynamical systems
The study of the analytic structure of nonlinear ordinary and partial differential equations is shown to provide a unified approach to determining their properties and finding their solutions.
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