Showing papers on "Up quark published in 1984"
TL;DR: In this paper, the consequences of an effective lagrangian for quarks, gluons and goldstone bosons in the region between the chiral symmetry breaking and confinement scales were studied.
1,582 citations
TL;DR: In this paper, the effect of quark antisymmetrization on one-pion exchange potential between two nucleons is investigated and it is found that the effect is very large at short distances.
48 citations
TL;DR: In this paper, the S-wave phase shifts of the KN system in the framework of a nonrelativistic quark model were calculated using variational methods (generator coordinates).
36 citations
TL;DR: In this paper, the effect of confinement in a quark-gluon plasma is described through a density dependent quark mass, and it is shown that the equation of state resulting from such a description is characterized by a sound velocity which agrees remarkably well with the phenomenologically extracted values from hadronic collisions over a large range of temperatures.
30 citations
TL;DR: In this article, it was shown that to leading order in the quark number N, the Skyrme model, strong coupling theory and the static quark model share a common underlying symmetry group.
23 citations
TL;DR: In this article, the relation between bare and renormalized coupling constants and quark masses in lattice and continuum QCD was investigated with special attention to numerical values, and it was shown that coupling values β = 6/g 0 2 ⪆ 6.2 are required for a satisfactory incorporation of realistic quarks masses.
18 citations
TL;DR: In the absence of O(α2) corrections, the quarks of charge 2 3 are four times as heavy as the corresponding quarks on charge 1 3, giving rise simultaneously to the phenomenon of flavor mixing as mentioned in this paper.
18 citations
TL;DR: In this paper, the violations of isospin symmetry induced in the two-nucleon system at the quark level by the mass difference between up and down quarks are studied in a quark cluster model.
15 citations
TL;DR: In this article, the nucleon axial and pion-nucleon isobar coupling constants are calculated in a non-relativistic quark model for baryons with a pion cloud.
5 citations
TL;DR: In this article, the color magnetic and electric fields, Ba and Ea, in the static cavity approximation of the MIT bag model were calculated rigorously for all direct and exchange four-currents of quarks in the S 1/2,P 1/ 2 and P 3/2 bag states.
Abstract: We calculate the colour magnetic and electric fields,Ba andEa, in the static cavity approximation of the MIT bag model. This is done rigorously for all direct and exchange four-currents of quarks in theS1/2,P1/2 andP3/2 bag states. We then find the quark-quark colour interaction for direct and exchange diagrams. The one-pion exchange diagrams due to chiral symmetry are also calculated.
5 citations
TL;DR: In this article, it is assumed that independent quark models describe hadrons bound in a fictitious external potential well Hadron properties in such models are only calculable after the effects of this binding (CM effects) have been removed.
TL;DR: In this article, a fourth generation of quark is considered which can fit the present experimental data on CP violation, and KL → μ+μ- decay rate for top quark mass is around 40 GeV.
Abstract: To explain CP violation in Kaon system in the light of the recently measured b-lifetime within the framework of three generations of quarks, the top quark mass has to be greater than 50GeV if the current algebra value of the factor BK is adopted and |'/| < 0.01. In this letter a fourth generation of quark is considered which can fit the present experimental data on CP violation, and KL → μ+μ- decay rate for top quark mass is around 40 GeV. The mass of the new charge 2/3 quark is predicted to be over 100 GeV.
TL;DR: In this paper, a single pion photoproduction was studied in a single quark model in which a quark absorbs the photon and then emits the pion, propagating as a quink between the two interactions.
Abstract: Single pion photoproduction is studied in a single quark model in which a quark absorbs the photon and then emits the pion, propagating as a quark between the two interactions. Two different chiral bag models are used which allow for the coupling of the quarks to the pion. Surprisingly, the single quark model reproduces the results of phenomenological models and agrees with the experimental amplitudes to within 30% at threshold.
01 Jan 1984
TL;DR: In this paper, the lifetime, branching ratio and the electron spectrum of heavy quark semileptonic decay were analyzed in a self consistent way and the K-M angle s3 was found to be < 0.0051 at 90% c. and = 0.044 ± 0.005 respectively.
Abstract: Heavy quark semileptonic decay data: lifetime, branching ratio and the electron spectrum are analyzed in a self consistent way. Values for the ∣Vub∣ and ∣Vcb∣ elements of the mixing matrix are determined to be <0.0051 at 90% c.1. and = 0.044 ± 0.005 respectively. Combining these results with nucleon and hyperon β-decay data the K-M angle s3 is found to be < 0.022 at 90% c.1. and s2 to be bounded between 0.044 and 0.066, and the mixing matrix to be almost diagonal.
TL;DR: In this article, the authors simulated the appearance of a top quark at a certain CM energy Wt and looked for the Wt value at which the self-consistency condition is satisfied.
TL;DR: In this paper, high density matter of quarks accompanying a condensed 7(0) field is studied in chiral bag model, and it is shown that this phase possibly occurs as an intermediate stage prior to the phase transition to uniform quark matter.
Abstract: High density matter of quarks accompanying a condensed 7(0 field is studied in chiral bag model, as a new phase arising from the neutron matter under 7(0 condensation. It is shown that this phase possibly occurs as an intermediate stage prior to the phase transition to uniform quark matter. Structure of the phase is characterized by the following features; the layers of the two·dimensional quark matter with a specific spin·flavor order and the condensed 7(0 field existent as the Nambu·Goldstone mode between the adjacent layers. Such quark configuration is caused due to the pion quark coupling at the layer (bag) surface which drastically lowers quark energy. Energy properties of the system are examined and stability of this phase is discussed.
TL;DR: In this article, a sum rule similar to the Adler-Weisberger relation was derived in the nonrelativistic quark model for the non-convex case.
Abstract: A sum rule similar to the Adler-Weisberger relation is derived in the nonrelativistic quark model.
TL;DR: In this paper, two relativistic potential models are applied to describe meson spectroscopy in a unified way, encompassing both light and heavy quark systems, and a combination of linear and coulomb potentials has been investigated for Klein-Gordon equation using the WKB approximation.
Abstract: Two relativistic potential models are applied to describe meson spectroscopy in a unified way, encompassing both light and heavy quark systems. A combination of linear and coulomb potentials has been investigated for Klein-Gordon equation using the WKB approximation. A power-like phenomenological potential model has also been studied in the Klein-Gordon framework. Meson masses calculated for both the potentials give a good agreement with the corresponding experimental values.
TL;DR: A general overview of quark models of hadrons is presented in this article, where experiment results and theoretical attempts to explain the data are discussed, including bag models and pion clouds, hadron masses and baryon magnetic moments, quark clustering and NN interactions.
Abstract: A general overview of quark models of hadrons is presented. Experiment results and theoretical attempts to explain the data are discussed. Bag models and pion clouds, hadron masses and baryon magnetic moments, quark clustering and NN interactions, and the GA/GV ratio are topics included in this review. (AIP)
01 Jan 1984
TL;DR: For a large class of phenomenological potential models motivated by quantum chromodynamics, this article studied the behaviour of bound state masses as the constituent mass is increased and found that the mass of a quark-antiquark bound state increased when a constituent mass was increased.
Abstract: For a large class of phenomenological potential models motivated by quantum chromodynamics, we have studied the behaviour of bound state masses as the constituent mass is increased and found that the mass of a quark-antiquark bound state increases when a constituent mass is increased. It appears, for these potentials, thatd quark is heavier thanu quark.
Book•
01 Jan 1984
TL;DR: The role of the quark-antiquark pair in the structure of nuclei and the role of quark effects in nuclear physics has been studied in this paper, with a focus on lattice gauge theories.
Abstract: and survey.- Recent developments in lattice gauge theories.- The hadron spectrum in lattice QCD.- Finite temperature QCD.- The quark-quark interaction in the nonrelativistic and in the lattice approximation.- Quark and gluon condensates in hadrons and in quark interactions and the role of the quark-antiquark pair in the structure of nuclei.- Quark effects in nuclear physics.- Chiral symmetry breaking and the pion.- Application of the cluster expansion to QCD.- The Cloudy Bag Model of hadrons.- Recent developments in Chiral Bag Models.- Centre of mass correction to bag model.- Dynamics of the soliton bag.- Quark distributions in nuclei and deep inelastic scattering of charged leptons.- Nuclear shells from a quark-theoretical viewpoint.- Effective QCD-Lagrangian for nuclear physics.- Strange quarks in low energy hadronic interactions.- The nucleon-nucleon interaction in the quark model.- A study of NN phase-shift calculations in a quark potential model.- Many-nucleon forces and currents derived from quark degrees of freedom+.- Quantitative spectroscopy with quarks.- Nuclear forces within a consistent meson-exchange model.- The short-range part of the NN-interaction quark-gluon versus meson exchange.- Quarks and the NN- and NN-interaction.- Boson-mediated interactions between static sources.
TL;DR: In this article, an intermediate phase prior to the phase transition to uniform quark matter, the quark alternating layer spin·flavor (ALSF) phase, is studied using the chiral bag model.
Abstract: An intermediate phase prior to the phase transition to uniform quark matter, the quark alternating layer spin·flavor (ALSF) phase, is studied using the chiral bag model. In addition to the quark and pion degrees of freedom included in this model the effects of gluon exchange between quarks are incorporated. Confined perturbation calculation of QCD is performed for each layer in the lowest order and energy properties of the system are examined. It is shown that one·gluon·exchange effect restores the stability of the layered structure, because its contribution to the energy is repulsive and inversely proportional to layer thickness.
Abstract: Assuming that physical quarks belonging to various generations are radial excitations of the bound states of a pair of massive constituent fermions and a scalar governed by the scalar-spinor Bethe-Salpeter equation with a harmonic kernel, we employ the instantaneous approximation to calculate relativistic corrections to the Kobayashi-Maskawa quark mixing matrix. We find that the corrections are not large if the quark mass differences are small compared to the constituent masses.
TL;DR: In this article, the negative-kaon size and the form factor were considered in a relativistic quark model and it was found that the model calculation agreed reasonably with the experimental value.
Abstract: The negative-kaon size and the form factor are considered in a relativistic quark model. It is found that the model calculation agrees reasonably with the experimental value.
01 Jan 1984
TL;DR: Some methods of perturbative and non-perturbative QCD are reviewed in this article, and the QCD sum rules are presented on the example of the p-meson.
Abstract: Some methods of the perturbative and non-perturbative QCD are reviewed The QCD sum rules are presented on the example of the p-meson; and the extension of the QCD sum rules from mesons to baryons, and to the meson-baryon coupling constant are given There are proposed some modifications of the short distance interactions; and the role of the quark-antiquark pair in the structure of nuclei is discussed in some detail
TL;DR: In this paper, a lecture spans developments in the subject of quark matter governed by Quantum Chromodynamics, the object is to examine phase transitions (possibly to nuclear matter) that occur in this system in the framework of many body perturbation theory.
01 Jan 1984
TL;DR: The Galilean Hamiltonian for QCD is presented and illustrated in this article, which exhibits a confining potential which, however, is a finite size effect, becoming purely Coulombic for infinite quantization volume.
Abstract: The Galilean Hamiltonian for QCD is presented and illustrated. In a small quantization box such Hamiltonian exhibits a confining potential which, however, is a finite size effect, becoming purely Coulombic for infinite quantization volume. This does not necessarily imply absence of confinement in Galilean QCD, and a possible mechanism for confinement is discussed, suggested by the exact solution of the infrared sector in Galilean QED.
CERN1
TL;DR: In this article, Lepton pairs with large invariant mass are proposed as a signal for the top quark decay and the background from different processes is estimated, and the multipleton final states from the sequential decay of the top-quark are studied.
Abstract: Multipleton final states from the sequential decay of the top quark are studied. Lepton pairs with large invariant mass are proposed as a signal for the top quark. The background from different processes is estimated.