A Schematic Model of Generation Structure

Koike, Kazuo

doi:10.1143/ptp.88.81

Cited by 9 publications

(19 citation statements)

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“…Moreover, from the information we can estimate the change of spectra for vector mesons in nuclear matter. The difference between these two approaches has been discussed in [10,6]. Eventually we derived in [6] that both of them are based on almost the same idea and can lead the consistent results with those of the effective models.…”

Section: Introductionmentioning

confidence: 70%

“…In particular, experimentally it is important to observe vector mesons, because they decay into lepton pairs and carry the information inside the matter without disturbance of the strong interaction. The properties of light vector mesons in nuclear matter have been extensively studied in various theoretical approaches such as effective hadronic models [2] and QCD sum rules (QSR's) [3,4,5,6]. Vacuum properties of the vector mesons have been successfully studied by the QSR's [7,8].…”

Section: Introductionmentioning

confidence: 99%

“…They found a 10 ∼ 20 % decrease of the ρ and ω mesons at normal matter density. Secondly, for light vector mesons we formulated in-medium QSR [4,6] based on the relation between a scattering length and a mass shift [9]. In this approach with the Fermi gas model, in-medium correlation function is devided into vacuum part and one nucleon part.…”

Section: Introductionmentioning

confidence: 99%

“…In this paper we apply the QSR analysis established in [6] to a heavy quark system with equal mass for quark and antiquark. As a concrete system we focus on J/ψ, which is a low-lying charmonium state ( 3 S 1 ).…”

Section: Introductionmentioning

confidence: 99%

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J/ -Nucleon Scattering Length and In-Medium Mass Shift of J/ in QCD Sum Rule Analysis

Hayashigaki

1999

Progress of Theoretical Physics

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We calculate the spin-averaged J/ψ-nucleon scattering length a J/ψ by directly applying the QCD sum rule to the J/ψ-N forward scattering amplitude. Our result, a J/ψ = −0.10 ± 0.02 fm, implies the possibility of bound states with nuclei, though the force is weaker than that of the light vector mesons (ρ, ω, φ)-N cases. Up to dimension-4 gluonic operators, we evaluate the scattering length with a twist-2 contribution. This increases the absolute value of the scattering length by about 30%. If we apply a J/ψ to the effective mass of J/ψ in nuclear matter on the basis of the linear density approximation, it exhibits very slight decrease (4-7 MeV) at normal matter density. §1. IntroductionTheoretical analysis on the in-medium properties of hadrons is increasingly necessary for various on-going and forthcoming heavy-ion experiments (such as SPS, LHC (CERN) and AGS, RHIC (BNL)). 1) In particular, experimentally it is important to observe vector mesons, because they decay into lepton pairs and carry the information inside matter without the disturbance of the strong interaction. The properties of light vector mesons in nuclear matter have been studied extensively in various theoretical approaches, including effective hadronic models 2) and QCD sum rules (QSR's). 3) -6) Vacuum properties of the vector mesons have been successfully studied using the QSR's. 7), 8) The method enables us to express physical quantities such as mass and decay width in terms of the parameters of the QCD Lagrangian and vacuum condensates. Extending the vacuum QSR to finite density, we can consistently incorporate the effects of nuclear matter into the form of in-medium condensates. There are two methodologically different ways for applying in-medium QSR. First, Hatsuda and Lee developed the in-medium QSR formalism for light vector mesons. 3) They found a 10 − 20% decrease of the masses of the ρ and ω mesons at normal matter density. Second, for light vector mesons, we formulated in-medium QSR 4), 6) based on the relation between the scattering length and the mass shift. 9) In this approach with the Fermi gas model, the in-medium correlation function is divided into a vacuum part and a one nucleon part. This one nucleon part corresponds to the forward vector meson-nucleon scattering amplitude. The QSR analysis on the forward scattering amplitude enables us to obtain information concerning the vector meson-nucleon interaction. Moreover, from this information we can estimate the change of spectra for vector mesons in nuclear matter. The difference between * )

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Section: Introductionmentioning

confidence: 70%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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J/ -Nucleon Scattering Length and In-Medium Mass Shift of J/ in QCD Sum Rule Analysis

Hayashigaki

1999

Progress of Theoretical Physics

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“…The profound meaning of the appearance of new hierarchical structure through this two step process may be clarified by new findings regarding dynamics of sub-structure and by further discoveries concerning the fundamental nature of matter. 1), 2) We have classified the gauge bosons appearing in GUTs, generational gauge bosons and the inter-generational gauge bosons. Our model provides some important predictions for the so-called proton decay problem.…”

Section: Discussionmentioning

confidence: 99%

Generation Structure and Proton Decay Problem

Koike

2001

Progress of Theoretical Physics

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Possible generation structure is investigated. We considere alternative possibility of combination of leptons and quarks to compose each generation, where the combination of $(\nu_{\tau},{\tau})$ and $(u,d)$ compose a generation. Our model exhibits the hierarcy structure after sea-saw mechanism provived that possible existence of realistic right-handed neutrinos are taken into account. Then, in the GUTs model based on our scheme, possible inter-generation properties are examined together with the classification of gauge bosons. It is shown that if our scheme is realized, the proton decay exhibits different mode from ordinary one.Comment: 9 page

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In-medium Σ0–Λ mixing in QCD sum rules

2002

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The Σ 0 − Λ mixing angle in isospin-asymmetric nuclear medium is investigated by using QCD sum rules. From the general consideration of the inmedium baryonic correlations, in-medium baryon mixings are shown to have several Lorentz structures such as the scalar mixing angle θ S and the vector mixing angle θ V . This causes a difference between the particle mixing θ (= θ S +θ V ) and the anti-particle mixing θ (= θ S − θ V ). From the finite energy sum rules for the Σ 0 − Λ mixing, we find that the in-medium part of the mixing angle has a relation θ S Med ∼ −θ V Med in the isospin-asymmetric medium. This implies that the medium affects mainly the anti-particle mixing. From the Borel sum rules, we obtain | θ − θ 0 | ≃ 0.39 |(ρ n − ρ p )|/ρ 0 with θ 0 , ρ n , ρ p and ρ 0 being the vacuum mixing angle, the neutron density, the proton density and the normal nuclear matter density respectively.

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A Schematic Model of Generation Structure

Cited by 9 publications

References 0 publications

J/ -Nucleon Scattering Length and In-Medium Mass Shift of J/ in QCD Sum Rule Analysis

J/ -Nucleon Scattering Length and In-Medium Mass Shift of J/ in QCD Sum Rule Analysis

Generation Structure and Proton Decay Problem

In-medium Σ0–Λ mixing in QCD sum rules

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