arXiv subjects

Muneyuki Ishida

Publications and source records attributed to Muneyuki Ishida.

At least 37 records · Page 2Linked to original sources

arXiv2005

On the Discrepancy of pp, pbar p Total Cross Sections at sqrt s = 1.8TeV

Based on the previous approach, we have investigated a possibility to resolve the discrepancy between the E710, E811 and CDF at sqrt s =1.8TeV, using the experimental data of the pp, pbar p total cross sections sigma tot(+) and rho(+)$ ratio up to the SPS experiments (sqrt s = 0.9TeV) as inputs. We predict sigma tot(pbar p) and rho(pbar p) at the Tevatron energy(sqrt s=1.8TeV) as sigma tot(pbar p)=75.9+- 1.0mb, rho(pbar p)=0.136+- 0.005. It turns out that only the data of E710 is consistent with the prediction in the one standard deviation. So we can conclude that E710 is preferable but we can exclude neither CDF nor E811 results.

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arXiv2005

Property of cn - nbar cbar System in U(12)-Scheme and X(3872),Y(3940)

The properties of four quark cn - nbar cbar states are investigated as cn di-quark and nbar cbar di-antiquark system in U(12)-classification scheme of hadrons. We consider the negative-parity di-quark and di-antiquark in ground states, and the properties of X(3872) and Y(3940) are consistent, respectively, with those of the JPC=1++ and 2++ states from these negative-parity di-quark and di-antiquark. Their narrow-widths are explained from an orthogonality of spinor wave functions. The properties of ground-state cs - sbar cbar system are also predicted in this scheme.

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arXiv2005

Four Quark cn - nbar cbar States in U(12)-Scheme and X(3872)/Y(3940)

The properties of four quark cn - nbar cbar states are investigated as cn di-quark and nbar cbar di-antiquark system in U(12)-classification scheme of hadrons, recently proposed by us. We consider the negative-parity di-quark and di-antiquark in ground states, which form with the ordinary positive-parity ones the respective linear representations of chiral symmetry. The masses and widths of ground-states are predicted by using Joint Spring Quark Model, and the observed properties of X(3872) and Y(3940) are consistent, respectively, with those of the JPC=1++ and 2++ states from the negative-parity di-quark and di-antiquark. Their narrow-widths are explained from an orthogonality of spinor wave functions. The properties of ground-state cs - sbar cbar system are also predicted in this scheme.

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arXiv2005

Predictions of pp, pbar p total cross section and rho ratio at LHC and cosmic-ray energies based on duality

Based on duality, we previously proposed to use rich informations on pi p total cross sections below N=10GeV in addition to high-energy data in order to discriminate whether these cross sections increase like log nu or log2 nu at high energies. We then arrived at the conclusion that our analysis prefers the log2 nu behaviours. Using the FESR as a constraint for high energy parameters also for the pp, pbar p scattering, we search for the simultaneous best fit to the data points of sigma(tot) and rho ratio up to some energy (e.g., ISR, Tevatron) to determine the high-energy parameters. We then predict sigma(tot) and rho in the LHC and high-energy cosmic-ray regions. Using the data up to E=1.8TeV (Tevatron), we predict sigma(tot)pp and rho(pp) at the LHC energy (E=14TeV) as 106.3+- 5.1syst +- 2.4stat mb and 0.126 +- 0.007syst +- 0.004stat, respectively. The predicted values of sigma(tot) in terms of the same parameters are in good agreement with the cosmic-ray experimental data up to Plab = 10 (8--9) GeV.

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arXiv2005

Ground State Baryons in U(12) Scheme

The properties of ground-state baryons of light-quarks are investigated in U(12)-classification scheme of hadrons, recently proposed by us. In U(12), in addition to the ordinary 56 of SU(6)SF, the existence of the extra 56 with positive-parity and 70 with negative-parity appear as ground-states in lower mass region. The N(1440), Lambda(1600) and Sigma(1660) have the plausible properties of masses and strong decay widths as the flavor-octet of extra 56, while the ordinary radially-excited octet states are expected not to be observed as resonances because of their large predicted widths of the decays to extra 70 baryons. The extra 70 baryons are not observed directly as resonances for the same reason, except for only the Lambda(1406), of which properties are consistently explained through the singlet-octet mixing. The baryon properties in lower mass regions are consistently explained in U(12) scheme.

hep-ph↗

arXiv2005

Predictions of pp, pbar p total cross section and rho ratio at LHC and cosmic-ray energies

We propose to use rich informations on the pp, pbar p total cross sections sigma below N=10 GeV in order to predict the total cross section and rho ratio at very high energies. Using the FESR as a constraint for high energy parameters, we search for the simultaneous best fit to the data points of sigma and rho ratio up to some energy (e.g., ISR, Tevatron) to determine the high-energy parameters. We then predict sigma and rho in the LHC and high-energy cosmic-ray regions. Using the data up to sqrt s =1.8 TeV(Tevatron), we predict sigma(pp) and rho(pp) at the LHC energy(sqrt s = 14 TeV) as 106.3 +- 5.1(syst) +- 2.4(stat) mb and 0.126 +- 0.007(syst) +- 0.004(stat), respectively. The predicted values of sigma in terms of the same parameters are in good agreement with the cosmic-ray experimental data sample up to Plab = 10^(8--9) GeV by Block, Halzen, and Stanov.

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arXiv2005

The DsJ*(2317) and DsJ(2460) mesons in U~(12)-classification scheme of hadrons

The narrow mesons, DsJ*(2317) and DsJ(2460), observed recently in the final states Ds+ pi0 and Ds*+ pi0 are pointed out to be naturally assigned as the ground-state scalar and axial-vector chiral states in the csbar system, which would newly appear in the covariant U~(12) hadron-classification scheme proposed a few years ago. We predict the comparatively large electromagnetic decay widths to other models, which are due to the intrinsic electric dipole moment. The SELEX state DsJ(2632) is also able to be assigned to the P-wave chiral state with JP=1- in the U~(12)-classification scheme.

hep-ph↗

arXiv2003

The Ds(2317) and Ds(2463) Mesons as Scalar and Axial-Vector Chiralons in the Covariant Level-Classification Scheme

The new narrow mesons observed recently in the final states Ds+ pi0 and Ds*+ pi0 are pointed out to be naturally assigned as the ground-state scalar and axial-vector chiralons in the c sbar system, which would newly appear in the covariant hadron-classification scheme proposed a few years ago.

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arXiv2003

Scalar Mesons and Chiral States

The essential points and physical backgrounds of the covariant level-classification scheme, based on U(12)SF * O(3,1)L, are reviewed: This scheme is extended from the non-relativistic SU(6)SF * O(3)L scheme by introducing the new SU(2)-spin (rho-spin) degree of freedom, which is necessary for covariant description of composite hadrons. Our scheme predicts the existence of new type of chiral mesons and baryons (Chiralons) out of the conventional SU(6)SF * O(3)L scheme. The sigma nonet is a typical example of chiralons to be assigned to the q qbar relativistic S-wave state. The new narrow mesons Ds(2317)/Ds(2463) are naturally assigned as the ground-state scalar and axial-vector chiralons in the c sbar system.

hep-ph↗

arXiv2003

Covariant Classification Scheme of Hadrons and Chiral States

The essential points and physical backgrounds of the covariant level-classification scheme, recently proposed by us, are reviewed: In this scheme the general composite hadrons are classified as the multiplets with the U(12)SF * O(3,1) symmetry, where U(12)SF supset U(4)D.S. * SU(3)F, and U(4)D.S. is a homogeneous Lorentz transformation group for Dirac spinors. This symmetry predicts the existence of new type of chiral mesons and baryons out of the conventional level classification scheme. The sigma nonet is a typical example of chiralons to be assigned to the q bar q relativistic S-wave state.

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arXiv2003

Properties of sigma and kappa Production Amplitudes

Our method of analysis, which led to existence of sigma and kappa mesons, is reviewed and examined from a viewpoint of general S-matrix. It is shown that the method is consistent with the constraints from chiral symmetry and unitarity. Accordingly the long-believed common analyses of pipi (Kpi) scattering and production processes, based on elastic unitarity, prove to lose its theoretical base. The observed phase motion by 180 degrees of sigma shows also the validity of our method.

hep-ph↗

arXiv2003

Relation between Scattering and Production Amplitudes -- Case of sigma and kappa in pipi and Kpi Systems --

In our talk at Nihon university symposium, we have argued that the pipi / Kpi production amplitudes F generally have different structures from those of the pipi / Kpi scattering amplitudes T from a viewpoint of generalized S matrix on the right bases, reflecting the quark-physical picture of strong interactions, and that F should be analyzed independently from T. Here we discuss the miscellaneous topics related with this argument: The conventional analyses by K matrix method, which necessarily lead to the common phases and structures through both T and F, are based on improper application of elastic unitarity to the production processes. Recent criticisms on the method of analyses of J/psi -> omega pipi and D+ -> K- pi+ pi+, which led to the existence of sigma and kappa, respectively, are also based on improper application of elastic unitarity.

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arXiv2003

Ground State Baryons in Covariant Level-Classification Scheme

In the covariant level-classification scheme of hadrons based on U(12)SF * O(3,1)L symmetry, the ground state baryons and antibaryons are assigned to the (12 * 12 * 12)Sym = 364-multiplet in the spin-flavor U(12)SF symmetry. This multiplet includes, in addition to the ordinary 56-multiplet of the static SU(6)SF, the extra chiral 56' and 70-multiplets, called "chiralons," which are expected to exist with masses in 1 -- 2 GeV region. Their electro-magnetic properties, magnetic moments and radiative decay amplitudes, are investigated. A longstanding puzzle, that the predicted value of the width Gamma(Delta -> N gamma) by the conventional treatment is inconsistently small with the experimental one, may be solved by the mixing effect of 56-states with the chiral 56'-states.

hep-ph↗

arXiv2003

Vector Component of Confinement Force and P-Wave Spectrum of D mesons

The mass spectrum and the pionic decay widths of the P-wave $D$ mesons are studied using the Dirac equation for the light quark. Our aim is to determine the Lorentz property of the confinement force. We find that the Lorentz scalar confinement is consistent with the mass spectrum, while a significant mixture of the Lorentz vector confinement is necessary to explain the decay widths.

hep-ph↗

arXiv2002

The Present Status on sigma and kappa Meson Properties

The recent experimental data of both pipi / Kpi scattering and production processes, suggesting the existence of scalar sigma and kappa mesons, are reviewed. In many pipi /Kpi production processes the direct effects of their productions are observed, while they are, because of chiral symmetry, hidden in scattering processes, and now sigma(500--600) and kappa(800--900) are considered to be confirmed experimentally. The recent criticism on our method of analyses, which is based on the long believed prejudice of universal pipi / Kpi phase through scattering and production amplitudes, is explained not to be valid.

hep-ph↗

arXiv2002

Possible Evidence for a Chiral Particle D_1chi, Axial-Vector in the D Meson System

In the covariant level-classification scheme of hadrons proposed recently, the existence of "chiral particles", scalar and axial-vector mesons as the partners of the ground-state pseudo-scalar and vector mesons, respectively, were predicted in the D and B meson systems, realizing a linear representation of chiral symmetry. In this work we reanalyze the D* pi mass spectra obtained through the Upsilon (4S) and Z0 decays to show a possibility for the D_1chi.

hep-ph↗

arXiv2002

Possible Evidence for a Chiral Particle B_0chi, Scalar Meson in the B Meson System

In the covariant level-classification scheme of hadrons proposed recently, the existence of "chiral particles", scalar and axial-vector mesons as the partners of the ground-state pseudo-scalar and vector mesons, respectively, were predicted in the D meson and B meson systems, realizing a linear representation of chiral symmetry. In this work we reanalyze the B0 pi mass spectra through Z0 decays to show a possibility for the scalar B_0chi.

hep-ph↗

arXiv2002

Investigations of the pi N total cross sections at high energies using new FESR: log nu or (log nu)^2

We propose to use rich informations on pi p total cross sections below N= 10 GeV in addition to high-energy data in order to discriminate whether these cross sections increase like log nu or (log nu)^2 at high energies, since it is difficult to discriminate between asymptotic log nu and (log nu)^2 fits from high-energy data alone. A finite-energy sum rule (FESR) which is derived in the spirit of the P' sum rule as well as the n=1 moment FESR have been required to constrain the high-energy parameters. We then searched for the best fit of pi p total cross sections above 70 GeV in terms of high-energy parameters constrained by these two FESR. We can show from this analysis that the (log nu)^2 behaviours is preferred to the log nu behaviours.

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