Showing papers on "Meson published in 1974"
TL;DR: In this paper, the equation of state for dense hyperonic matter is calculated from five potential interaction models, the form of the potential is the same as that of Reid, a sum of Yukawa functions, the coefficients of which are adjusted separately in each partial wave to fit experimental nucleon nucleon data.
207 citations
TL;DR: In this paper, a model of the space-time structure of hadronic collisions is proposed, which provides a parameter-free account of National Accelerator Laboratory and cosmic-ray emulsion data, which shows that the multiplicity of mesons produced in nuclei exceeds that in hydrogen by an energyindependent ratio remarkably close to unity.
Abstract: Nuclear interactions at high energy are sensitive to the space-time structure of basic hadronic collisions. A model of this structure is proposed; it provides a parameter-free account of National Accelerator Laboratory and cosmic-ray emulsion data, which shows that the multiplicity of mesons produced in nuclei exceeds that in hydrogen by an energy-independent ratio remarkably close to unity.
148 citations
TL;DR: In this article, the elastic electromagnetic and weak form factors for nucleons, π and K mesons were studied and the experimental data as well as theoretical approaches were reviewed for these form factors.
114 citations
TL;DR: In this paper, the self-consistent equation for fermion propagator in a vector-gluon model is fully examined, and it is proved that with a suitable gauge chosen, the equation without ~utoff has solutions only in the case mo=O, it is then shown that, if g'/4n Bn, the "normal-state" solution without cutoff, even if it existed, should necessarily have an unphysical singularity.
Abstract: Solutions of the self-consistent equation for fermion propagator in a vector-gluon model are fully examined. The equation is characterized by a set of parameters, i.e., the coupling constant g, the bare mass of the fermion mo and the cutoff A. It is proved that with a suitable gauge chosen, the equation without ~utoff has solutions ·only in the case mo=O, It is then shown that, if g'/4n Bn, the "normal-state" solution for the equation without cutoff, even if it existed, should necessarily have an unphysical singularity. This fact implies that the "normal-state" solution becomes unstable for a su.fficiently large value of g'. § l. Introduction The. reason for success of low energy theorems obtained by current algebra and PCAC-treatment may be well understood in terms of chiral symmetry in which the pseudoscalar mesons play a special role among hadtons as the Nambu Goldstone (NG) bosons1l transforming nonlinearly under chiral transformation. On the other hand, in the composite hadron models based on SU(3) or SU(6), it is clear that there is no vital distinction between pseudoscalar mesons and others such as vector- and tensor-mesons. It is therefore worth expecting that the pseudoscalar NG bosons can also be interpreted as the bound states in con formity with the viewpoint of the composite model. . This homogeneity and· heterogeneity ot the pseudoscalar mesons to other mesons should rather be in vestigated by comparing their internal structure with composite particles· . . In this respect it would be meaningful to study a model in which spontaneous breaking of chiral symmetry is realized by a composite NG boson: The Nambu Jona-Lasinio model2l is known as such an example. However, the use of chain approximation and the momentum cutoff inevitable for the local four-fermion
106 citations
CERN1
TL;DR: In this paper, a detailed description is given of the partial wave analysis of any reaction of the kind: meson + proton → proton + (3 mesons) and it is shown that with little modification, the method can be applied to the study of special four-meson systems like Kω.
90 citations
TL;DR: In this paper, the presence of meson exchange currents in the tri-nucleon system is shown to modify significantly the charge form factor of 3 He in the region of the dip and the secondary maximum.
78 citations
76 citations
TL;DR: In this article, the classification of resonant particles and some currently popular symmetries for describing their decays are reviewed and the successes of SU(3), Regge trajectories, and the quark model are noted.
71 citations
TL;DR: In this article, it was shown that quasinuclear meson resonances are distinguished by comparatively large partial width for decay into nucleon and antinucleon, and that there exist nuclear-like bound and resonant states in NN system, all near threshold states having nonzero orbital angular momenta of relative N and N motion.
71 citations
TL;DR: In this paper, the authors measured the cross section for the production of mesons by the Primakoff process at bremsstrahlung energies of 5.8, 9.0, and 11.45 GeV.
Abstract: The cross section for the phtotproduction of $\ensuremath{\eta}$ mesons by the Primakoff process has been measured at bremsstrahlung energies of 5.8, 9.0, and 11.45 GeV. A value of 0.324 \ifmmode\pm\else\textpm\fi{} 0.046 keV was obtained for the partial width of the $\ensuremath{\eta}$ meson decaying into photon pairs. This result is a factor of 3 lower than the previously accepted value.
66 citations
TL;DR: In this article, total cross sections for π + and π − mesons on 6 Li, 7 Li, 9 Be and C have been measured in the energy range from 90 to 860 MeV, and for oxygen from 88 to 228 MeV.
TL;DR: A display device includes a controller and a display panel, which receives original image data and output a display image signal, and an image shift controller, which generates the display images signal by processing the shifted image data.
Abstract: The cross section for the photoproduction of ${\ensuremath{\pi}}^{0}$ mesons from complex nuclei at small angles has been measured at incident bremsstrahlung energies of 4.4 and 6.6 GeV. The data are fitted by a cross section calculated from a sum of Primakoff and nuclear-production amplitudes. A total decay width for the ${\ensuremath{\pi}}^{0}$ meson of 8.02\ifmmode\pm\else\textpm\fi{}0.42 eV is obtained from the magnitude of the Primakoff amplitude.
TL;DR: In this paper, a number of constraints, several new, are exploited to obtain realistic quark parton distributions for baryons and mesons, and these distributions are used to make detailed predictions for NN or π N → l + l − + anything, potentially providing a quantitative test of the quark Parton model.
TL;DR: In this paper, it was shown that only a small number of elementary cells in phase space are populated in a multiparticle production reaction even at high energy, leading to occupancy numbers for identical bosons in individual cells which are not small.
Abstract: It is shown that only a small number of elementary cells in phase space are populated in a multiparticle production reaction even at high energy (g 100 GeV), leading to occupancy numbers for identical bosons in individual cells which are not small. It follows that quantum-statistical fluctuations are of significant magnitude. The effects on multiplicity distributions and integral correlation functions of $\ensuremath{\pi}$ mesons produced in high-energy interactions are derived. Comparison with experimental results at incident energies above 100 GeV indicates that Bose-Einstein fluctuations may be a principal source of broadening of the multiplicity distribution and of positive short-range correlations among identical particles. The effect is nondynamical and nonkinematical in the usual sense, but is due to identical-particle symmetry, and is the counterpart of the Hanbury Brown-Twiss effect in the electromagnetic field.
TL;DR: In this article, the leptonic decay rates of K-mesons were used to impose rather stringent constraints on the average transverse momentum of the quarks composing the K-means.
CERN1
TL;DR: In this paper, the available charge exchange data for π N → ϱ N, π n → ω N and ϱ − ω interference effects in the momentum range 6-17 GeV /c are analyzed.
TL;DR: In this article, the influence of isobar admixture and meson exchange current effects on the total and differential cross section and the polarization in the reaction d(γ,p)n is investigated.
TL;DR: In this article, a many-body theory is developed where the Hilbert space is allowed to contain states of nucleons and mesons and the basis of the theory is the treatment of a field theoretical Hamiltonian within non-covariant perturbation theory.
TL;DR: In this paper, the Bonn 2.5 GeV synchrotron was used to measure the differential photoproduction cross section d σ /d t of φ mesons at a photon energy of 2.0 GeV at fibe different t values between 0.23 t | c ) 2.
TL;DR: In this article, a coupled channel treatment of the two-baryon system is carried out in order to study the effects of baryon-resonance components in nuclear states.
TL;DR: In this paper, from simple quark model arguments and assuming a quadratic η − η mixing, the radiative decays of the vector and pseudoscalar mesons were predicted.
TL;DR: In this paper, a complex and energy-dependent mixing formalism was proposed for the ω − ϕ case, where the effects of finite width and inelastic effects were considered.
TL;DR: Differential cross sections for the elastic scattering of K+ mesons on protons have been measured at 12 lab momenta between 130 and 755 MeV/c using a hydrogen filled bubble chamber as discussed by the authors.
TL;DR: In this article, the constituent symmetry group U(6) is incorporated in the null plane quark model of mesons, and the value m u =5.4 MeV and m s =125−160 MeV for the masses of the nonstrange and the strange quarks respectively.
TL;DR: In this article, it was shown that baryon-antibaryon annihilations into mesons contribute, via unitarity, mainly to the pomeron term in the total B B cross section.
TL;DR: In this article, the recoil proton was detected in coincidence with the scattered electron and the reaction was observed at three four-momentum transfers of the virtual photon: q2 = 0.2, 0.28 and 0.4 (GeV/c).
TL;DR: In this article, the reactions pp→pp+meson, where meson= η, ϱ 0, ω, and f, have been investigated at P inc = 12 and 24 GeV/ c.
TL;DR: In this paper, the angular distribution of the π+ meson has been measured at angles up to 70° from the virtual photon direction for isobar masses in the range 1400 → 1600 MeV/c2 and, over a small angular range, close to the virtual-photon direction for masses between 1600 and 1860 MeV /c2.