abstract

The conditions of isotropy of pressure in a perfect fluid undergoing irrotational shearfree motion lead to differential equations, which may be used to obtain exact solutions for inhomogeneous distributions.

abstract

Assuming that the magnetic moment operator transforms as \((24, 3_{s})\) component of the 220-representation of U(10), we computed the magnetic moments of the fancy particles, at first in the C–C\(^{\prime }\) model of Achiman, Kollar and Walsh and then in an alternate model where the new quark has a charge \(Q = -1/3\). As expected all results in U(8) stayed unchanged, and we expressed the magnetic moments of the particles with new quantum number fancy in terms of the magnetic moment of the proton.

abstract

A relation between jet, background, total multiplicity distributions, average multiplicities and the high \(p_{\bot }\) particle spectrum is derived. Specific forms of distributions and spectra, KNO-scaling and possible connections with experimental data are discussed.

abstract

The presently known experimental data on multimesonic decays of \(\psi \) and \(\chi \) states are fitted in a constant matrix element quark model taking into account also resonances and both strong and second order electromagnetic processes. The known data are well reproduced and the branching ratios for the rest of multimesonic channels are predicted. The fit leaves about 40% for baryonic and radiative channels in the case of J\(/\psi \). The parameters of the J\(/\psi \) decays are used to predict the mesonic decays of the pseudoscalar \(\eta _c\). Some multiparticle production aspects of these decays are also emphasized.

abstract

We use Dirac’s equation with a long range harmonic potential to obtain the mass spectra of the neutral vector mesons \(\rho ^0\), \(\omega \), \({\mit \Phi }\), K\(^0\) and \(\psi \). Our predictions are in fairly good agreement with the experimental results.

abstract

The procedure of Speer’s analytic regularization is repeated for \(d\)-dimensional space-time (\(d\) is arbitrary). It is shown that the generalized propagators (\(m^2-p^2-i0)^{-\lambda }\) (\(\lambda \) is an arbitrary complex number) as well as products of such expressions can be analytically continued to all values of \(\lambda -d/2\). For nonrational values of d the location of poles in the generalized amplitudes is shifted away from the physical value \(\lambda = 1\). The magnitude of this dislocation remains finite for the perturbation order tending to infinity.

abstract

Similarities in the high-energy behaviour, elastic and inelastic collisions, of hadrons and nuclei are interpreted as due to the existence of a universal interacting hadronic matter distribution function. Differences arise from the different geometrical dimensions which are themselves determined by the quark content. We formulate the idea in an eikonal model, the only parameters being geometrical factors, the transverse radius and the opacity parameter. The model describes forward elastic scattering (hadron–hadron, hadron–nucleus, nucleus–nucleus interactions) and particle production at high energies. We discuss the relation of our model to the Glauber model as well as to the quark model and to the geometrical ideas in QCD.

abstract

Single-major shell Hartree–Fock calculations of the doubly even \(N=Z\) nuclei in the \(2s-1d\) shell have been performed using velocity-dependent effective potential of \(s\)-wave interaction. The results are compared with previous calculations as well as with the experimental data. Good agreement is obtained between the calculated binding energies and the experimental ones.

abstract

Spin and isospin stability of dense neutron and nuclear matter with hard core interaction of radius \(c\) is studied using expansion in powers of gaseousness parameter, \(x = k_Fc\), and variational approach. Variational calculations are performed using Jastrow method, including the contribution from three-body clusters. The correlation function has been obtained from Euler’s equation resulting from constrained minimization of two-body cluster contribution with subsidiary healing condition. The optimum value of healing integral has been subsequently determined by minimizing the sum of the two- and three-body cluster contributions. In the case of neutron matter, both methods lead to conclusion that in the region of their validity the hard core model is spin stable. Numerical results obtained for hard core model of nuclear matter suggest a spin and isospin instability at \(x \cong 1\)–1.3, where, however, applicability of our methods is doubtful.