Showing papers on "Pseudoscalar published in 1983"
TL;DR: In this article, the relativistic Hartree-Fock (HF) equations for an infinite system of mesons and baryons were derived based on a diagrammatic approach and Dyson's equation for the baryon propagator.
124 citations
CERN1
TL;DR: In this paper, the authors discussed the QCD sum rules for the correlators of pseudoscalar currents with quantum numbers of π, K, η, Ϸ′ mesons, and concluded that all these phenomena are very well reproduced by this model.
119 citations
TL;DR: In this article, a potential model for mesons is presented, which combines quark confinement and strong decay in a realistic approach, and the multichannel Schr\"odinger formalism is employed to describe a system of one or more permanently closed quark-antiquark channels in interaction with several two-meson channels.
Abstract: A potential model for mesons is presented, which combines quark confinement and strong decay in a realistic approach. The multichannel Schr\"odinger formalism is employed to describe a system of one or more permanently closed quark-antiquark channels in interaction with several two-meson channels. For the potential in the $q\overline{q}$ channels a harmonic oscillator with constant frequency is taken. As for the meson channels only Okubo-Zweig-Iizuka-rule-allowed decays into two mesons of the pseudoscalar or vector type are considered. Final-state interactions between these mesons are not yet taken into account. The communication between confined and free channels is supposed to take place via the $^{3}P_{0}$ mechanism, for which a locally approximated transition potential is derived. In order to obtain an analytic solution for the $S$ matrix, the transition potential is treated by using a multi-$\ensuremath{\delta}$-shell method. Kinematically relativistic corrections and color splitting allow a fairly successful treatment of pseudoscalar as well as vector mesons for all quark flavors. The results are confronted with the data and discussed.
96 citations
01 Jan 1983
TL;DR: By means of relativistic QCD sum rules, the leptonic decay constants of the pseudoscalar D and B mesons were calculated as discussed by the authors, f/sub D/approx.
Abstract: By means of relativistic QCD sum rules the leptonic decay constants of the pseudoscalar D and B mesons are calculated: f/sub D/approx. =170 MeV and f/sub B/approx. =130 MeV.
89 citations
01 Dec 1983
TL;DR: By means of relativistic QCD sum rules, the leptonic decay constants of the pseudoscalar D and B mesons were calculated as discussed by the authors, f/sub D/approx.
Abstract: By means of relativistic QCD sum rules the leptonic decay constants of the pseudoscalar D and B mesons are calculated: f/sub D/approx. =170 MeV and f/sub B/approx. =130 MeV.
68 citations
TL;DR: In this article, a general expression for the two-photon form factor of neutral pseudoscalar mesons is given in a quark triangle model, which is in agreement with other calculations based on vector meson dominance, giving a new example of Q2 duality.
49 citations
TL;DR: In this paper, the coupling constants in QCD were derived by extrapolating from the asymptotic freedom regime using QCD sum rules, where the amplitudes are dominated by the quark condensate when one leg is a pseudoscalar Goldstone boson.
46 citations
CERN1
TL;DR: In this paper, the decay of a pseudoscalar meson into a lepton pair has been estimated for the case of the neutral pion into electron and positron.
Abstract: QED radiative corrections to the decay of a pseudoscalar meson into a lepton pair have been estimated. The results are applied to the decay of the neutral pion into electron and positron. Formulas are also given for a pseudoscalar Higgs-like particle decaying to a lepton or quark pair. The results are also of relevance for QCD sum rules for the pseudoscalar current, where conflicting calculations exist in the literature.
33 citations
Journal Article•
TL;DR: In this article, a low energy effective Lagrangian was derived for a nonet of pseudoscalar mesons (including the Wess-Zumino-Witten interaction) directly from the fundamental Langrangian of quantum chromodynamics.
Abstract: A low-energy effective Lagrangian can be derived for a nonet of pseudoscalar mesons (incorporating the Wess-Zumino-Witten interaction) directly from the fundamental Langrangian of quantum chromodynamics.
29 citations
TL;DR: In this article, the authors studied two aspects of the antinucleon-nucleon annihilation into two mesons (N N → M 1 M 2 ) starting from simple Born diagrams.
23 citations
TL;DR: In this paper, the authors treated light and heavy pseudoscalar and vector mesons as non-relativistic quarkonia and calculated various decay modes, including lowest QCD corrections.
TL;DR: In this article, neutral mesons were used to test the quark-line rule for a given hadronic system and the pseudoscalar mixing angle theta/sub PS/ in agreement with theoretical estimates.
Abstract: Production of several neutral mesons in reactions involving u, d, u-bar, and d-bar quarks only can be used to test the quark-line rule for a given hadronic system. Recent data on pp-bar..-->..(two neutral pseudoscalars) are analyzed yielding restrictions on the pseudoscalar mixing angle theta/sub PS/ in agreement with theoretical estimates. It is emphasized that production of neutral mesons at LEAR can provide meaningful tests of the quark-line rule and theoretical predictions of theta/sub PS/. .AE
TL;DR: In this paper, the authors analyzed the effects of some electroweak interaction models with a composite W at present energies and found that the width of the W into pairs of pseudoscalar bosons can be appreciable and may reduce its leptonic branching ratio by about 20%.
TL;DR: In this paper, the authors determined the value of mixing parameter x from the transition energies between pi -mesoatomic states in nuclei from 12C to 209Bi as x=-0.32+or-0.01.
Abstract: Recently it was shown that the nuclear stability against pion condensation can be caused by interference between pseudovector and pseudoscalar pi N interactions. The authors determined the value of the mixing parameter x from the transition energies between pi -mesoatomic states in nuclei from 12C to 209Bi as x=-0.32+or-0.01. For such values of x the nuclear matter is close to pion condensation at densities 0.25n0
TL;DR: In this article, the mass spectrum and radiative decays of the low lying pseudoscalar and vector mesons in a nonrelativistic model were analyzed and the mixing of the gluonium candidate ι(1440) with the J PC = 0 −+ quarkonium candidates were discussed.
TL;DR: In this article, a discrepancy is observed between higher-order QED calculations and a recent experiment on the decay rate of the orthopositronium, and it is conjectured that this can be due to a possible pseudoscalar interaction of the electron-positron field.
Abstract: A discrepancy is apparent between the higher-order QED calculations and a recent experiment on the decay rate of the orthopositronium. It is conjectured here that this can be due to a possible pseudoscalar interaction of the electron-positron field.
TL;DR: In this paper, the renorm-group equations for the most general case of five pseudoscalar charges were derived for the 2D self-avoiding walk problem and it was shown that the pseudoscalar charges lead to the absence of stable fixed points.
TL;DR: In this paper, the authors calculate the contribution of the $W$ and $Z$ mesons to the radiative corrections to the leptonic decays of pseudoscalar mesons.
Abstract: Using the current-algebra formalism we calculate, within the Salam-Weinberg model, the contribution of the $W$ and $Z$ mesons to the radiative corrections to the leptonic decays of pseudoscalar mesons.
TL;DR: In this paper, the authors considered a scalar-pseudoscalar four-Fermi quantum field model in four dimensional space-time and derived a new formula for the generating functional for collective boson and fermion Green functions in terms of the effective propagators.
TL;DR: Using an improved version of the Van Royen-Weisskopf formula, the leptonic decay widths, decay constants of ψ, and pseudoscalar particles have been computed in the statistical model as mentioned in this paper.
Abstract: Using an improved version of the Van Royen-Weisskopf formula, the leptonic decay widths, decay constants of ψ, and pseudoscalar particles have been computed in the statistical model. The calculated results are found to compare favourably with the experimental findings and other theoretical estimates.
CERN1
TL;DR: In this paper, the authors present results which seem to differ from previous theoretical calculations found in the literature, for the Bethe-Heitler process of light pseudoscalar particles off nuclei.
TL;DR: In this article, a two-component reduction of Dirac wavefunctions and operators is used to identify situations where Dirac and Schrodinger phenomenology differ significantly and improve agreement between theory and experiment for various nuclear direct reactions.
TL;DR: In this article, the mixing between a glueball and qq pseudoscalars (both the ground state and the first radial excitation) was calculated in the framework of the MIT bag model.
TL;DR: In this paper, the pseudoscalar glueball mass and its mixing with the η′ are studied in quantum chromodynamics, incorporating the chiral U 3 × U 3 algebra.
TL;DR: In this paper, the chiral Ward identities for the pseudoscalar mesons including the recently identified glueball state G(1440) were reanalyzed in the hope that the solution for the decay constants will shed light on the interpretation of G( 1440) as a gluonic bound state.
Abstract: We reanalyze the chiral Ward identities for the pseudoscalar mesons including the recently identified glueball state G(1440), in the hope that the solution for the decay constants will shed light on the interpretation of G(1440) as a gluonic bound state. Even when supplemented with experimental rates for (psi..-->..eta'..gamma..)/(psi..-->..eta..gamma..) and (eta'..--> gamma gamma..)/(eta..--> gamma gamma..)/(..pi../sup 0/+..gamma gamma..) we cannot obtain definite predictions for the pseudoscalar decay constants and for G..--> gamma gamma.., because the solutions are exceedingly sensitive to poorly known parameters. Classes of solutions are presented, which are functions of B(G..-->..KK-bar..pi..); a solution is only possible if B(G..-->..KK-bar..pi..) gamma gamma..) is 5 keV, although much smaller values are quite reasonable.
TL;DR: In this paper, it was shown that there exist two light pseudoscalar mesons, which are linear combinations of pure quark and pure glueball states, and a new functional method was developed to determine the effective action for the appropriate fields in a low-energy approximation.
TL;DR: In this paper, the electromagnetic form factors of pseudoscalar mesons have been calculated in the ACD-theory of hadrons, by making use of meson wf's with momentum p ≠ 0.
TL;DR: Spin is incorporated into the hadronic topological expansion scheme in this article, where spin analogs of Chan-Paton factors are introduced in a way that avoids the troubles encountered in earlier attempts.
Abstract: Spin is incorporated into the hadronic topological expansion scheme. Spin analogs of Chan-Paton factors are introduced in a way that avoids the troubles encountered in earlier attempts. Those troubles, at the meson level, were, first, the occurrence of twice the wanted number of pseudoscalar and vector mesons; second, the occurrence of parity-doublet partners of the pseudoscalar and vector mesons; and third, the occurrence of these parity-doublet partners as particles of negative metric, called ghosts. These troubles are all avoided by introducing a new topological level, called zero entropy, that lies below the ordered level. At the zero-entropy level quarks of opposite chirality are treated as distinct particles. The theory has been extended to all hadrons, and the basic particles are exactly those of the constituent-quark model, which for baryons start with the (56/sup +/) and (70/sup -/). The theory is formulated in the M-function framework, where the ''quarks'' are represented by two-component spinors, and it entails SU(6)/sub W/ symmetry of the hadronic vertices at a low level of the topological expansion.
TL;DR: In this paper, it was shown that parity and time reversal, as basic geometric symmetry operations, are conserved in strong interactions and the neutrino plays an essential role in these considerations.
Abstract: We show that it is possible to consider parity and time reversal, as basic geometric symmetry operations, as being absolutely conserved. The observations of symmetry-violating pseudoscalar quantities can be attributed to the fact that some particles, due to their internal structure, are not eigenstates of parity or CP, and there is no reason that they should be. In terms of a model it is shown how, in spite of this, pseudoscalar terms are small in strong interactions. The neutrino plays an essential role in these considerations.
TL;DR: In this article, two inequivalent spin 1/2 baryon field operators that can be constructed directly out of three quark field operators are associated with a pair of parity partners.
Abstract: There are two inequivalent spin 1/2 baryon field operators that can be constructed directly out of three quark field operators. These are associated with a pair of parity partners. Their chiral transformation properties yield some unexpected results. In particular.U(1) axial transformations can mix the two operators. With these chiral transformation properties the spin 1/2 baryon parity partners are incorporated in an effective chiral lagrangian together with the spin 0 meson fields. The mass splitting of these parity partners is then found to be related to their coupling to the flavour singlet pseudoscalar,
$$M_ - - M_ + \simeq F_\pi g_{\mathop {flavour}\limits_{singlet} N_ - N_ + } $$
The further selection rule, in the exact chiral limit,
$$g_{\pi N_ + N_ - } = 0$$
is also found. Using these results, and their extension to the non-chiral limit, the enhancement of the decay ofN− intoN+ η, as opposed toN+ π, is elucidated even though it is suppressed by phase space. Two flavours is given principle consideration although three flavours is also briefly discussed.