Showing papers on "Strangeness published in 1974"

Gravitational charges, f-gravity and hadron masses

Abstract: Two types of fundamental gravitational charges are suggested by quantization of the angular momentum (ie J=nħ, wheren is an integer or half integer) occurring in the uncharged and charged Kerr metrics These charges turn out to bee/√a ande/a, wheree is the unit electric charge anda the fine structure constant The use of strong (f) gravity leads to corresponding fundamental massesM1(f) ∼22×10−24 g andM2(f)∼23×10−23 g It is postulated that the hadrons are composed of these fundamental entities (christened oms here) Thus mesons arediomic particles and baryons aretriomic particles This has a close resemblance to the quark model but here we deal with gravitational charges The charges constituting hadrons are bound together by strong (f) gravity which is super strong compared to nuclear forces Various hadron masses are obtained as the vibrational excitations of these composite units The above model is capable of accounting for quantum numbers such as spin, baryon number, strangeness and isospin

Spontaneous "Cabibbo" suppression

Abstract: We demonstrate the possibility of a unified weak-electromagnetic gauge scheme in which the suppression of strangeness-changing weak amplitudes arises by spontaneous breakdown of an SU(3) symmetry.

Experimental systematics of particle lifetimes and widths

Abstract: By comparing the lifetimes of the metastable (τ>10−17 s) elementary particles with one another, we find experimentally that these lifetimes occur both as ratios of 2 and as ratios of α=e2/ħc, with supposedly dissimilar particles grouped together, and with no experimental counterexamples. When short-lived (τ ∼ 10−22 s) meson and baryon resonances are studied, it is found that the width is a key identification symbol. Grouping together resonances that have similar (narrow) widths, we obtain very accurate linear mass intervals. This mapping can be extended to include essentially all of the observed narrow-width meson and baryon resonances in a comprehensive pattern. These results suggest a weak-binding-energy approach to elementary-particle structure. This is the same conclusion that emerges from a broad overview of the successes of the quark model. The empirical level spacings point to the existence of two basic mass quanta, a spinless quantum μ ⋍ 70 MeV and a spin-1/2 quantumS ⋍ 330 MeV. Electromagnetic properties of nucleons also indicate the existence of the 330 MeV mass quantum. In reconciling a 330 MeV mass quantumS with a 939 MeV nucleon mass and a 1795 MeV\(\bar pn\) bound-state mass, we are led to the Fermi and Yang formulation of the nucleon rather than to the formulation of Gell-Mann and Zweig. The observed spectrum of narrow-width meson and baryon resonances can be reproduced by forming suitable combinations of the quanta μ andS. Broad-width resonances are interpreted as rotational excitations. Basis states 3 ≡ 3μ and 4 ≡ 4μ, initially selected to account for observed level spacings in hyperon resonances, are shown to have significance with respect to strangeness quantum numbers and with respect to basic characteristics of baryon and meson resonances. These basis states can also be used to account phenomenologically for the observed factors of 2 and α in the lifetimes of the metastable resonances. The predictive power of the present linear systematics is illustrated in a «meson excitation tower» for narrow-width resonances. First published in 1970, this excitation tower is shown with separate groupings for the resonances that were identified in 1970 and for the resonances that have subsequently been identified.

Weak interactions at short distances

Abstract: The weak interaction increases with lncreasing energy The form of the interaction is presented Real processes at high energy include: elastic scattering of leptons, the interaction of the neutrino with nucleons, inelastic scattering of leptons, lower limit for elastic e/sup +/e/sup -/-scattering cross section, the behavior of the total cross sections of the weak interactions of leptons at energies above the unitary limit Under virtual processes the review covers: lepton interactions, electromagnetic interactions of leptons, weak interactions of leptons such as mu -decay, elastic nu /sub e/ e/sup -/- scattering, elastic nu /sub mu / e/sub e/-scattering and ela stic e/sub e/- scatiering, hadron--lepton interactions, weak neutral currents, ratio of vector constant of BETA - and mu -decay, nonleptonic interactions, and hadron processes with a change in strangeness, parity or isotopic spin Also attempts to construct a new theory of weak interactions are considered 114 references (SJR)

Symmetries and conservation laws in neutrino physics

Abstract: The basic conservation laws of neutrino physics are described, and the experimental limits on their validity are discussed. The best limit comes from double beta decay, and it shows that lepton number and helicity are conserved in charged weak current processes to order 3 × 10−4. No such limits are available for the recently discovered neutral currents, and so the speculation is made that there may be a large breakdown of the usual helicity rule for neutrinos in neutral current interactions. Experiments to test this speculation are suggested in neutrino scattering off various targets, in neutral beta decay, and in pseudoscalar meson decay. The roles of iso‐spin and strangeness in neutral currents are also discussed. Predictions based upon lepton conservation and helicity are made for the decay distributions of heavy leptons.

Exotic bound states of strange hadrons

Abstract: A negatively charged strange hadron can be bound by the electromagnetic interaction in the Coulomb field of a nucleus to form an exotic atom. De-excitation of such an atom occurs with the emission of X-rays whose energies, line widths, and intensities have been measured. Deviations from the electromagnetic level scheme are observed for lower-lying states owing to the strong interaction of a hadron with a nucleus. When the wave function of a hadron begins to overlap with the nuclear density distribution, the hadron undergoes nuclear absorption via the strong interaction. The final outcome of such a process is the formation of a Λ hyperon which may be bound in a nucleus by the strong interaction. An exotic nucleus, or a hyper-nucleus, is thus formed making it possible to study the Λ–nucleon interaction. Excited states of hypernuclei decaying via weak, electromagnetic, or strong interaction have been observed and are extensively studied. Investigation of exotic atoms and hypernuclei provides basic i...

Gauge models without charmed hadrons

Abstract: We investigate the possibilities for constructing unified gauge models of the weak and electromagnetic interactions without charmed hadrons. Methods for suppressing both direct and induced strangeness-changing neutral currents are suggested and we consider their experimental consequences.

Results of the Neutral Current Search in Gargamelle

Abstract: The weak interaction is phenomenologically described as the coupling of two currents both of which have a vector and an axial vector part. Until the experiment I will describe to you today, only a charge carrying current was necessary to explain all observed experimental data. It has, in fact, been verified that the branching ratio of the neutral current (N.C.) mediated decay process which simultaneously changes strangeness (i.e. K L 0 → e+e-) is less than 10-9, many orders of magnitude below the charged current (C.C.) process.

Electromagnetic-Mass Formula and a Model of Baryons.

Abstract: How to explain the electromagnetic-mass difference of hadrons has been one of the problems embarrassing people for a long time. Field-theoretically it is difficult to take out the main effect of the complicated strong interactions. Experimentally, electromagnetic masses of hadrons seem to have values which allow no simple quali tat ive explanation. When two baryons in an isomultiplet are compared, a baryon with less charge has always larger mass. Such an experimental tendency, however, seems to suggest that these masses are distributed under a certain law. Such an indication also appears in the fact tha t the mean mass difference of baryons in an isomultiplet increases with the absolute value of the strangeness S. The well-know Coleman-Glashow relation