Regular Series


Vol. 9 (1978), No. 6, pp. 475 – 549


Some Exact Solutions of Charged Fluid Spheres in General Relativity

abstract

The paper presents a family of interior solutions of the Einstein–Maxwell field equations of general relativity for a static, spherically symmetric distribution of charged fluid. The family of solutions have been matched with the Reissner–Nordstrom metric at the boundary. The solution of Adler can be obtained from these when charge is absent.


On Weak Form Factors in Nuclear Muon Capture

abstract

The roles of the various weak hadronic form factors in the ground to ground state transition rate and the recoil polarization in muon capture by \(^{12}\)C and \(^{16}\)O are analysed using best available nuclear wave functions and compared with the conventional Fujii–Primakoff approximation. It is concluded that the recoil nuclear polarization of \(^{12}\)B(1\(^+\)) can safely be used to examine the induced pseudoscalar and tensor form factors. A plausible value for the induced tensor form factor is obtained by comparing with the experimental value for the \(^{12}\)B(1\(^+\)) average polarization and is in agreement with the recent \(\beta \)-decay experimental results.


Remark on the Models of Line-Reversal Symmetry Breaking

abstract

The analysis of two body strangeness exchange processes in baryon–antibaryon and baryon-baryon scattering could discriminate between the two existing explanations of the difference between line-reversed reactions. In the case when the pattern of line-reversal symmetry breaking in \(B\)–\(B\) and \(B\)–\(\overline {B}\) scattering is similar to that in the meson–baryon scattering — simple rearrangement model is favoured. In the other case the absorption model based on the dual unitarisation scheme with different Pomerons for qq and qq scattering is preferred.


all authors

J. Babecki, B. Furmańska, R. Hołyński, A. Jurak, G. Nowak, H. Wilczyński, W. Wolter, B. Wosiek

Interactions of Pions and Protons with Emulsion Nuclei at 60 GeV and 200 GeV

abstract

Parametrizations of multiplicity distributions of shower particles and evaporation tracks as well as correlations between them are analysed. The observed differences for pion and proton interactions at the same energy are consistent with the hypothesis that the relevant parameter which determines production process is the mean free-path of the incident particle inside the nucleus.


Multiplicities and Rapidity Distributions Associated with a Large \(p_{\bot }\) Trigger

abstract

We assume that the background formed by the spectator constituents in a hard scattering process behaves like a normal low \(p_{\bot }\) event at reduced energy and shifted rapidity corresponding to overall energy-momentum conservation. The model rather well describes the data on multiplicities for trigger \(p_{\bot } \gt 1.5\) GeV/\(c\). We predict the behaviour of associated multiplicities for trigger exceeding 4 GeV/\(c\). The associated background rapidity distribution is considerably affected at large cms trigger rapidity and with rising trigger transverse momentum.


all authors

S. Yuldashev, T.H. Burnett, H.J. Lubatti, K. Moriyasu, H. Rudnicka, A. Wróblewski

Multiplicity of Charged Particles in \(\pi ^-\) Neon Interactions at 25 and 50 GeV/\(c\)

abstract

The multiplicity distributions of charged particles produced in \(\pi ^-\) Ne interactions at 25 and 50 6eV/\(c\) are presented and compared with r nucleus and  t nucleon data. It is found that for the produced negative particles, the dependence of the dispersion on the average multiplicity is compatible with that observed for \(\pi ^{\pm }\)p and \(\pi ^{\pm }\)d interactions. We observe that the average multiplicity of produced negatives, \(\left \lt N^{\underline {\rm Pr}}\right \gt \), is correlated with the number of observed protons, \(N_p\), and obtain an effective target mass \(m_{\rm eff}\simeq (N_{\rm ~} + 1)m_{\rm p}\).


Some Radiative Decays of Vector Mesons and Baryons in the MIT Bag Model

abstract

The radiative decays \(\varrho \to \pi \gamma \), \(\omega \to \pi \gamma \), \(K^* \to K\gamma \), and \({\mit \Delta }^+ \to {\rm p}\gamma \) are discussed in the MIT bag model. It is shown that except for the case of \(\omega \to \pi \gamma \) the calculated results are generally in rough agreement with experiment. The connection wiih magnetic moment calculations in the bag model is stressed.


Relativistic Barriers for Two Spin-1/2 Particles

abstract

We separate the angular coordinates in relativistic Breit equation with a central potential, and then split it into a system of 16 radial equations. We show in the case of positive potentials \(V = \alpha /r\) and \(V = \mu ^2r\) that after elimination of all wave-function components but one some relativistic barriers appear between or around two Dirac particles. An energy-dependent radius of such a barrier separates the relative space of two particles into an inner region of partial confinement and an outer region of repulsion. The existence and character of solutions in the partial confinement regions require further investigation.


Decay Constants of the “Charmed” \(D\) and \(F\) Mesons

abstract

Following current algebra ideas, the semi-leptonic decays of \(D\) and \(F\) mesons are studied. An estimate of the ratio of the decay constants of these mesons is obtained which agrees fairly well with other theoretical predictions.


Is \(\chi (3505)\) a Vector Boson?

abstract

Although direct experimental information on the \(J^P\) values for the \(\chi \)(3415), \(\chi \)(3505), \(\chi \)(3550) is still not available, their values have been recently suggested by the SLAC-LBL group to be 0\(^+\), 1\(^+\), 2\(^+\) respectively for \(\chi \)(3415), \(\chi \)(3505), \(\chi \)(3550). It is suggested in this note that the \(\chi \)(3505) is not a vector boson.


ERRATUM for Acta Phys. Pol. B 9, 3 (1978)

Isoareal Transformations of the Kerr–Newman Black Holes


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