Showing papers on "Meson published in 1976"
CERN1
TL;DR: In this article, a linear binding potential with one-gluon exchange corrections, within a colour gauge field theory including four types of quarks, is applied to the description of the meson masses and leptonic widths (both for light and heavy mesons).
126 citations
TL;DR: In this article, the authors report the measurements of the inclusive $ensuremath{\mu}$-pair production by 150-GeV protons and mesons on beryllium.
Abstract: We report the measurements of the inclusive $\ensuremath{\mu}$-pair production by 150-GeV protons and ${\ensuremath{\pi}}^{+}$ mesons on beryllium. Absolute cross sections as well as the Feynman-$x$ and ${P}_{T}$ dependence are presented in the mass region between 0.211 and 3.5 ${\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c}}^{2}$. Upper limits are also given for the inclusive production of $\ensuremath{\eta}$ and ${\ensuremath{\rho}}^{\ensuremath{'}}(1600)$ mesons.
117 citations
112 citations
TL;DR: In this article, the effects of meson exchange currents on elastic and inelastic electron scattering from nuclei are considered with specific applications to 3 He, 6 Li, 7 Li, 9 Be and 10 B.
99 citations
TL;DR: In this article, the non-leading particles in pp collisions are fitted by a simple general formula, and the contributions from the ϱ0, ω, φ, and Jψ decays to the direct lepton spectra are calculated.
91 citations
TL;DR: In this article, the production of π and η mesons at 90° from proton-proton collisions has been measured at the CERN ISR at centre-of-mass energies between 23.5 and 62.4 GeV.
86 citations
CERN1
TL;DR: In this paper, it was shown that the I=0 s-wave ππ scattering amplitude near KK threshold can be parametrized in terms of a wide resonance, that is, the S∗ may have a large partial width into π π, and all the 0+ mesons may have large widthsf.
82 citations
01 Jan 1976
TL;DR: A review of CP violation and K/sup 0/decays can be found in this paper, where a phenomenological description of K/Sup 0/Decays is given.
Abstract: The review of CP violation and K/sup 0/ decays covers a phenomenological description of K/sup 0/ decays, the detection of K/sup 0/ decays, experiments on CP violation in K/sup 0/ decays, and searches for C or T violation. 186 references. (JFP)
78 citations
TL;DR: In this paper, the influence of meson exchange currents and isobar configurations on the electrodisintegration of the deuteron has been investigated for excitation energies below pion threshold and momentum transfer up to q 2 = 14 fm −2.
78 citations
Book•
01 Jan 1976
TL;DR: In this paper, the authors introduce elementary particles and invariance principles, including Lorentz invariance, charge independence, isospin and strangeness, and charge conjugation.
Abstract: Preface 1. Introduction to elementary particles 2. Quantum mechanics and invariance principles 3. Angular momentum 4. Lorentz invariance 5. Parity 6. Time reversal 7. Charge independence, isospin and strangeness 8. Charge conjugation 9. Hadronic decays of mesons 10. SU(3) 11. The quark model Appendices Index.
75 citations
TL;DR: In this article, the authors derived dimensional scaling predictions for the B(q2)A(q 2) ratio in the Rosenbluth formula, multiple-photonexchange corrections, and the mass parameters which control the onset of the asymptotic power law in the meson, nucleon, and deuteron form factors.
Abstract: The large-q2 behavior of the elastic form factor of a hadron or nucleus is related by dimensional counting to the number of its elementary constituents. Using the framework of a scale-invariant quark model, dimensional-scaling predictions are derived for the B(q2)A(q2) ratio in the Rosenbluth formula, multiple-photonexchange corrections, and the mass parameters which control the onset of the asymptotic power law in the meson, nucleon, and deuteron form factors. A simple "democratic chain" model predicts that for large q2, F(q2)∝(1−q2mn2)1−n, where mn2 is proportional to the number of constituents n. In the case of nuclear targets (or systems with several scales of compositeness), we also define the "reduced" form factor fA(q2)=FA(q2)Πi=1A[Fi(qi2)] in order to remove the minimal falloff of FA due to the nucleon form factors at qi2=(mi2MA2)q2. Dimensional counting predicts (q2)A−1fA(q2)→const. A systematic comparison of the data for π, p, n, and deuteron form factors with the dimensional-scaling quark-model predictions is given. Predictions are made for the large-spacelike-q2 He3 and α-particle form factors. We also relate the deuteron form factor to (off-shell) fixed-angle n−p scattering, and show that the experimental results for t5Fd(t) are consistent with the magnitude of the s-wave wave function u′(0) obtained from soft-core potentials. The relation of the dynamics of an underlying six-quark state of the deuteron to the nucleon-potential and meson-exchange-current contributions is discussed. The scaling of q2fd(q2) implies that the nuclear potential (after removing the effects of nucleon structure) displays the scale-invariant behavior of a theory without a fundamental length scale. Predictions are also given for the structure functions, fragmentation, and large-angle scattering of a nucleus.
TL;DR: In this article, the intercepts of the nonstrange meson and baryon Regge trajectories are simply related to quark spin, and the possibility arises if one adopts a multi-peripheral bootstrap for these (ordinary) trajectories and also a perturbative recipe relating a process with a given number of particles.
Abstract: The possibility is explored that the intercepts of the nonstrange meson and baryon Regge trajectories are simply related to quark spin. This possibility arises if one adopts a multiperipheral bootstrap for these (ordinary) trajectories and also a perturbative recipe relating a process with a given number of particles to quark-gluon diagrams. The possible implication of the scheme for the Pomeron is also discussed.
TL;DR: In this article, a partial wave analysis of the K$sup +-$$pi$$sup +$$pi $$sup -$p system in K$Sup +-$p $Yields$ K$SUP +-$pi$$SUP +$$PI$$sup - $p at 13 GeV.
Abstract: We present a partial-wave analysis of the K$sup +-$$pi$$sup +$$pi$$sup - $ system in K$sup +-$p $Yields$ K$sup +-$$pi$$sup +$$pi$$sup -$p at 13 GeV. Evidence is given for the existence of two J/sup P/ = 1$sup +$ mesons: one at approx. 1300 MeV(GAMMA approx. 200 MeV), coupling principally to rhoK, and the other at approx. 1400 MeV (GAMMA approx. 160 MeV), coupling principally to K*$pi$. (AIP)
TL;DR: The authors suggested that the structure observed between 3.9 and 4.5$ GeV at SPEAR is due to the presence of exotic mesons composed of a charmed diquark and antidiquark.
Abstract: I suggest that the structure observed between $\sqrt{s}=3.9 \mathrm{and} 4.5$ GeV at SPEAR is due to the presence of exotic mesons composed of a charmed diquark and antidiquark. Arguments for the existence of such mesons are reviewed. The characteristic features, i.e., masses, narrow widths, and abundance, which enable them to explain the data are presented. Further properties and yet another narrow meson with $m\ensuremath{\approx}6.7$ GeV/${\mathit{c}}^{2}$ is predicted.
TL;DR: In this paper, the large q/sup 2/ falloff of the elastic deuteron form factor was used to relate meson exchange to underlying quark currents, and to demonstrate scale-invariant behavior of the nucleon-nucleon potential.
Abstract: The large-q/sup 2/ falloff of the elastic deuteron form factor is used to relate meson exchange to underlying quark currents, to relate the deuteron form factor to large-angle n-p scattering, to demonstrate scale-invariant behavior of the nucleon-nucleon potential, and to determine the deuteron wave function at small n-p separation. (AIP)
01 Sep 1976
TL;DR: In this paper, an effective Schrodinger equation for the nucleonic components is derived from a covariant field theoretical Hamiltonian and the meson exchange currents are defined unarbitrarily by an effective operator (current) in the space of the nucleus components.
Abstract: We describe the nucleus by a meson-nucleon system. Starting from a covariant field theoretical Hamiltonian we derive an effective Schrodinger equation for the nucleonic components. The meson-exchange currents are then defined unarbitrarily by an effective operator (current) in the space of the nucleonic components. The advantage over theS-matrix method [1] is discussed. In the nonrelativistic limit the meson-current as well as the seagull (pair) current agrees with theS-matrix result. Recoil and wavefunction orthogonalization cancels completely in this limit.
TL;DR: In this paper, all direct leptons not due to vector meson decay can be attributed to the decay of virtual photons, and the ratio of direct photons to pions to be about 10 to 20% for sqrt[s]≈20-60 GeV.
Abstract: We propose that all direct leptons not due to vector meson decay can be attributed to the decay of virtual photons. At p⊥≈3 GeV/c, we expect γ / π, the ratio of direct photons to pions, to be about 10 to 20% for sqrt[s]≈20-60 GeV.
TL;DR: In this article, the spectrum of low-lying charmed mesons is determined using available data on new mesons discovered at SPEAR and a number of simple tests are proposed to confirm the charm interpretation.
Abstract: Available data on new mesons discovered at SPEAR are sufficient to determine the spectrum of low-lying charmed mesons and to provide a complete description of the threshold structure of $R$ in the framework of the charmonium model. A number of simple tests are proposed to confirm the charm interpretation.
TL;DR: In this article, the meson-proton scattering was found to be independent of momentum and meson type for -t > 14 (GeV/c)/sup 2/ and the momentum dependence of the pp dip was investigated.
Abstract: Elastic scattering of hadrons on protons has been measured at momenta of 50, 100, and 200 GeV/c The meson-proton scattering is found to be independent of momentum and meson type for -t > 08 (GeV/c)/sup 2/ The momentum dependence of the pp dip at -t = 14 (GeV/c)/sup 2/ was investigated Slope parameters are given (AIP)
TL;DR: The γ spectra induced by stopped K − mesons in a 7 Li target were obtained in coincidence with the accompanying charged pions as discussed by the authors, and a thorough analysis of these spectra indicates that the observed 109 MeV line can be attributed to a γ transition in the 4 Λ H hypernucleus.
CERN1
TL;DR: In this paper, the final state structure of proton-proton collisions is studied in the split field magnet detector at the CERN Intersecting Storage Rings, where a large transverse momentum π 0 (p t > 2 GeV/c ) is produced at an angle of 90°.
TL;DR: In this article, the K + meson was observed to have branching ratios of (10±3) ×10 −7 and (2 +2 −2 )×10−7 respectively.
TL;DR: In this article, the production and decay properties of δ (970) have been investigated in the following reactions: K − p → Σ + (1385) ηπ − and k − p ar Σ+ ( 1385)K 0 K −.
TL;DR: In this article, an invariant mass spectrum of μ + μ − pairs produced by 70 GeV/ c protons in Be target is presented, and the total cross section for the reaction p + Be → ( J ψ → (J ψ + μ + ) + … is equal to 9.5 ± 2.5 nb/nucleus.
TL;DR: In this article, the J/subP/=0/sup -/ partial waves of the Kpi pi pi.. system in the reactions K/sup plus-or-minus/p.
Abstract: The J/subP/=0/sup -/ partial waves of the K..pi pi.. system in the reactions K/sup plus-or-minus/p..-->..K/sup plus-or-minus/..pi../sup +/..pi../sup -/p at 13 GeV are presented. Structure in intensities and relative phase variations suggest the existence of a pseudoscalar resonance, the K', with a mass of approx.1400 MeV and a width of approx.250 MeV decaying predominantly into epsilonK. (AIP)
TL;DR: In this paper, a simple model of o−ω mixing in photoproduction incorporating e + e − →o−ω couplings, a simple quark model, and VMD was presented.
CERN1
TL;DR: In this paper, the diffractive elastic neutrino production of vector mesons has been studied in detail and the results of this analysis encourage experimental effort which may provide useful information concerning the nature of neutral currents and of the recently discovered new particles.
TL;DR: In this paper, it was proposed that the production of psi/J mesons in hadronic collisions occurs via processes involving gluons, and that reactions with /sup 3/P charmonium intermediate states play a significant role.
Abstract: It is proposed that the production of psi/J mesons in hadronic collisions occurs via processes involving gluons, and that reactions with /sup 3/P charmonium intermediate states play a significant role. The clarity of the observed psi/J signal and the differences between production rates of psi/J in pion- and nucleon-induced reactions are explained naturally. We calculate the total and differential cross section for producing psi/J + anything, and compare to data. Also, we have calculated the decay rates of the /sup 3/P states into two gluons; these results may be interesting in their own right. (AIP)