Results for "Kazuyuki Ogata"

total 758took 0.09s
Microscopic calculation of inelastic proton scattering off $^{18}$O, $^{10}$Be, $^{12}$Be, and $^{16}$C for study of neutron excitation in neutron-rich nucleiAug 09 2019The microscopic coupled-channel calculation of inelastic proton scattering is performed for the study of neutron excitations in $2^+_1$ states of $^{18}$O, $^{10}$Be, $^{12}$Be, and $^{16}$C. Proton-nucleus potentials in the coupled-channel calculation ... More
Direct probing of the cluster structure in ${}^{12}$Be via $α$-knockout reactionFeb 08 2019May 07 2019Background: Recent theoretical and experimental researches using proton-induced $\alpha$-knockout reactions provide direct manifestation of $\alpha$-cluster formation in nuclei. In recent and future experiments, $\alpha$-knockout data are available for ... More
Quantum mechanical description of excitation energy distribution of the reaction residue in nucleon-induced inclusive one-nucleon knockout reactionsJan 30 2018Understanding of inclusive one-nucleon knockout reactions for long-lived fission fragments (LLFPs) is crucial for nuclear transmutation studies. However, the particle and heavy ion transport code system (PHITS) severely overshoots the inclusive one-nucleon ... More
Manifestation of α-clustering in $^{10}$Be via α-knockout reactionDec 28 2017Apr 01 2018Background: Proton-induced {\alpha}-knockout reactions empower direct experimental manifestations of {\alpha}-clustering in nuclei. This is obtained by relating the theoretical descriptions of clustering states with experimental reaction observables. ... More
Toward a reliable description of ${(p,pN)}$ reactions in inverse kinematicsAug 02 2019Background: Proton-induced nucleon knockout $(p,pN)$ reactions have been successfully used to study the single-particle nature of stable nuclei in normal kinematics with the distorted-wave impulse approximation (DWIA) framework. Recently, these reactions ... More
Applicability of the continuum-discretized coupled-channels method to the deuteron breakup at low energiesJul 18 2016Aug 19 2016We re-examine the deuteron elastic breakup cross sections on 12C and 10Be at low incident energies, for which a serious discrepancy between the continuum-discretized coupled-channels method (CDCC) and the Faddeev-Alt-Grassberger-Sandhas theory (FAGS) ... More
Consistency between the monopole strength of the Hoyle state determined by structural calculation and that extracted from reaction observablesMar 06 2016We analyze the $\alpha$-$^{12}$C inelastic scattering to the $0^+_2$ state of $^{12}$C, the Hoyle state, in a fully microscopic framework. With no free adjustable parameter, the inelastic cross sections at forward angles are well reproduced by the microscopic ... More
Self-consistent microscopic description of neutron scattering by $^{16}$O based on the continuum particle-vibration coupling methodOct 09 2012The microscopic description of neutron scattering by $^{16}$O below 30 MeV is carried out by means of the continuum particle-vibration coupling (cPVC) method with the Skyrme nucleon-nucleon ($NN$) effective interaction. In the cPVC method, a proper boundary ... More
Low lying excited states of $^{24}$O investigated by self-consistent microscopic description of proton inelastic scatteringDec 27 2013The proton inelastic scattering of $^{24}$O($p,p'$) at 62 MeV/nucleon is described by a self-consistent microscopic calculation with the continuum particle-vibration coupling (cPVC) method. The SLy5, SkM*, and SGII parameters are adopted as an effective ... More
Dynamical Relativistic Effects in Breakup Processes of Halo NucleiDec 09 2009Feb 22 2010The continuum-discretized coupled-channels (CDCC) method is used to study the breakup of weakly-bound nuclei at intermediate energies collisions. For large impact parameters, the Eikonal CDCC (E-CDCC) method was applied. The effects of Lorentz contraction ... More
Extending the Eikonal Approximation to Low EnergyNov 21 2014E-CDCC and DEA, two eikonal-based reaction models are compared to CDCC at low energy (e.g. 20AMeV) to study their behaviour in the regime at which the eikonal approximation is supposed to fail. We confirm that these models lack the Coulomb deflection ... More
Quantum three-body calculation of the nonresonant triple-αreaction rate at low temperaturesMay 01 2009Jul 22 2009The triple-\alpha reaction rate is re-evaluated by directly solving the three-body Schr\"odinger equation. The resonant and nonresonant processes are treated on the same footing using the continuum-discretized coupled-channels method for three-body scattering. ... More
Deuteron-nucleus total reaction cross sections up to 1 GeVAug 19 2016Total reaction cross sections of deuteron, $\sigma_d^{\rm R}$, are calculated by a microscopic three-body reaction model. The reaction model has no free adjustable parameter and applicable to reactions at various deuteron incident energies $E_d$ and with ... More
$α$ scattering cross sections on $^{12}$C with microscopic coupled-channel calculationMar 25 2019$\alpha$ elastic and inelastic scattering on $^{12}$C is investigated with the coupled-channel calculation using microscopic $\alpha$-$^{12}$C potentials, which are derived by folding the Melbourne $g$-matrix $NN$ interaction with the matter and transition ... More
Asymmetry of the parallel momentum distribution of (p,pN) reaction residuesMay 25 2015Oct 08 2015The parallel momentum distribution (PMD) of the residual nuclei of the 14O(p,pn)13O and 14O(p,2p)13N reactions at 100 and 200 MeV/nucleon in inverse kinematics is investigated with the framework of the distorted wave impulse approximation. The PMD shows ... More
Breakup and finite-range effects on the 8B(d,n)9C reactionApr 18 2014Jan 07 2015The astrophysical factor of $^8$B($p$,$\gamma$)$^9$C at zero energy, $S_{18}(0)$, is determined by a three-body coupled-channels analysis of the transfer reaction $^{8}$B($d$,$n$)$^{9}$C at 14.4 MeV/nucleon. Effects of the breakup channels of $d$ and ... More
Borromean Feshbach resonance in 11Li studied via 11Li(p,p')Nov 20 2017A dipole resonance of 11Li is newly found by a 9Li + n + n three-body model analysis with the complex-scaling method. The resonance can be interpreted as a bound state in the 10Li + n system, that is, a Feshbach resonance in the 9Li + n + n system. As ... More
Three-Body Model Calculation of Spin Distribution in Two-Nucleon Transfer ReactionJan 14 2011The differential cross sections of two-nucleon transfer reactions 238U(18O,16O)240U around 10 MeV per nucleon are calculated by one-step Born-approximation with a 16O+2n+238U three-body model. The three-body wave function in the initial channel is obtained ... More
Reexamination of microscopic optical potentials based on multiple scattering theoryDec 29 2017Microscopic optical potentials have been successful in describing nucleon-nucleus and nucleus-nucleus scattering. Some essential ingredients of the framework, however, have not been examined in detail. Applicability of the microscopic folding model is ... More
Microscopic coupled-channel calculations of nucleus-nucleus scattering including chiral three-nucleon-force effectsSep 15 2015We analyze $^{16}$O-$^{16}$O and $^{12}$C-$^{12}$C scattering with the microscopic coupled-channels method and investigate the coupled-channels and three-nucleon-force (3NF) effects on elastic and inelastic cross sections. In the microscopic coupled-channels ... More
Three-Body Model Analysis of Subbarrier alpha Transfer ReactionApr 07 2011Subbarrier alpha transfer reaction 13C(6Li,d)17O(6.356 MeV, 1/2+) at 3.6 MeV is analyzed with a alpha + d + 13C three-body model, and the asymptotic normalization coefficient (ANC) for alpha + 13C --> 17O(6.356 MeV, 1/2+), which essentially determines ... More
Eikonal Reaction Theory for Neutron-Removal ReactionMar 21 2011May 24 2011We present an accurate method of treating the one-neutron removal reaction at intermediate incident energies induced by both nuclear and Coulomb interactions. In the method, the nuclear and Coulomb breakup processes are consistently treated by the method ... More
Investigating the alpha-clustering on the surface of $^{120}$Sn via ($p$,$pα$) reaction and the validity of the factorization approximationMar 02 2016Sep 28 2016The $^{120}$Sn($p$,$p\alpha$)$^{116}$Cd reaction at 392 MeV is investigated with the distorted wave impulse approximation (DWIA) framework. We show that this reaction is very peripheral mainly because of the strong absorption of $\alpha$ by the reaction ... More
Ferromagnetic Ising Spin Chains Emerging from the Spin Ice under Magnetic FieldJun 10 2003Sep 19 2003A spin-ice compound dysprosium titanate, Dy2Ti2O7, is studied by specific heat measurements in magnetic fields applied along the [110] direction of the cubic unit cell. Above a magnetic field of 0.4 T a relatively sharp peak at T = 1.1 K in the specific ... More
Analysis of a low-energy correction to the eikonal approximationJan 27 2014Sep 24 2014Extensions of the eikonal approximation to low energy (20MeV/nucleon typically) are studied. The relation between the dynamical eikonal approximation (DEA) and the continuum-discretized coupled-channels method with the eikonal approximation (E-CDCC) is ... More
First microscopic coupled-channel calculation of $α$ inelastic cross sections on $^{16}$OApr 08 2019The $\alpha$ inelastic scattering on $^{16}$O is investigated with the coupled-channel calculation using the $\alpha$-nucleus coupled-channel potentials, which are microscopically derived by folding the the Melbourne $g$-matrix $NN$ interaction with the ... More
Nef and big divisors on toric weak Fano 3-foldsMar 04 2009Oct 24 2013We show that a nef and big line bundle whose adjoint bundle has non-zero global sections on a nonsingular toric weak Fano 3-fold is normally generated. As a consequence, we see that all ample line bundles on a nonsingular toric weak Fano 3-fold are normally ... More
Projective normality of nonsingular toric varieties of dimension threeDec 04 2007Feb 25 2010We show that if an ample line bundle L on a nonsingular toric 3-fold satisfies h^0(L+2K)=0, then L is normally generated. As an application, we show that the anti-canonical divisor on a nonsingular toric Fano 4-fold is normally generated.
Ample line bundles on a certain toric fibered 3-foldsApr 29 2011Let $X$ be a projective nonsingular toric 3-fold with a surjective torus equivariant morphism onto the projective line. Then we prove that an ample line bundle on $X$ is always normally generated.
A ${\mathbb Z}_2$-index of symmetry protected topological phases with time reversal symmetry for quantum spin chainsOct 02 2018We introduce a ${\mathbb Z}_2$-index for time reversal invariant Hamiltonians with unique gapped ground state on quantum spin chains. We show this is an invariant of a $C^1$-classification of gapped Hamiltonians.
Approximating macroscopic observables in quantum spin systems with commuting matricesNov 25 2011Macroscopic observables in a quantum spin system are given by sequences of spatial means of local elements $\frac{1}{2n+1}\sum_{j=-n}^n\gamma_j(A_{i}), \; n\in{\mathbb N},\; i=1,...,m$ in a UHF algebra. One of their properties is that they commute asymptotically, ... More
A generalization of the inequality of Audenaert et alNov 05 2010We extend the inequality of Audenaert et al to general von Neumann algebras.
Decoherence free algebraJul 06 2003Jul 22 2003We consider the decoherence free subalgebra which satisfies the minimal condition introduced by Alicki. We show the manifest form of it and relate the subalgebra with the Kraus representation. The arguments also provides a new proof for generalized L\"{u}ders ... More
A global pinching theorem of complete $λ$-hypersurfacesApr 03 2015May 27 2015In this paper, the pinching problems of complete $\lambda$-hypersurfaces in a Euclidean space $\mathbb R^{n+1}$ are studied. By making use of the Sobolev inequality, we prove a global pinching theorem of complete $\lambda$-hypersurfaces in a Euclidean ... More
Normal generation of very ample line bundles on toric varietiesNov 05 2007Nov 13 2007The article has been withdrawn by the author due to the existence of counterexamples.
Orbital Magnetism of Bloch Electrons II. Application to Single-Band Models and Corrections to Landau-Peierls susceptibilityJun 06 2016Orbital susceptibility for Bloch electrons is calculated for the first time up to the first order with respect to overlap integrals between the neighboring atomic orbitals, assuming single-band models. A general and rigorous theory of orbital susceptibility ... More
Projective normality of toric 3-folds with non-big adjoint hyperplane sections, IIOct 24 2013Let $(X, A)$ be a nonsingular polarized toric 3-fold. We show that if the adjoint bundle of $A$ has no glabal section, then all ample line bundles on $X$ are normally generated. Even if the adjoint bundle is effective, if it is not big, then it is shown ... More
The continuum discretized coupled-channels method and its applicationsMar 24 2012This is a review on recent developments of the continuum discretized coupled-channels method (CDCC) and its applications to nuclear physics, cosmology and astrophysics, and nuclear engineering. The theoretical foundation of CDCC is shown, and a microscopic ... More
A New Glauber Theory based on Multiple Scattering TheoryJul 24 2008Sep 26 2008Glauber theory for nucleus-nucleus scattering at high incident energies is reformulated so as to become applicable also for the scattering at intermediate energies. We test validity of the eikonal and adiabatic approximations used in the formulation, ... More
Determination of S17 from 7Be(d,n)8B reaction: CDCC analyses based on three-body modelOct 07 2002The astrophysical factor $S_{17}$ for $^7$Be($p,\gamma$)$^8$B reaction is reliably extracted from the transfer reaction $^7$Be($d,n$)$^8$B at $E=7.5$ MeV with the asymptotic normalization coefficient method. The transfer reaction is accurately analyzed ... More
Direct probing of the cluster structure in ${}^{12}$Be via $α$-knockout reactionFeb 08 2019Feb 14 2019Background: Recent theoretical and experimental researches using proton-induced $\alpha$-knockout reactions provide direct manifestation of $\alpha$-cluster formation in nuclei. In recent and future experiments, $\alpha$-knockout data are available for ... More
Investigation of $α$ clustering with knockout reactionsDec 25 2017Aug 11 2018Our goal is to reveal how the $\alpha$ cluster amplitude is probed through $\alpha$ knockout reactions depending on reaction conditions, e.g., the incident energy. We consider $^{20}$Ne($p$,$p\alpha$)$^{16}$O and $^{120}$Sn($p$,$p\alpha$)$^{116}$Cd at ... More
Direct probing of the cluster structure in ${}^{12}$Be via $α$-knockout reactionFeb 08 2019Background: Recent theoretical and experimental researches using proton-induced $\alpha$-knockout reactions provide direct manifestation of $\alpha$-cluster formation in nuclei. In recent and future experiments, $\alpha$-knockout data are available for ... More
Probing three-nucleon-force effects via (p,2p) reactionsApr 28 2017We propose to use proton knockout reactions (p,2p) from a deeply bound orbit as a new probe into three-nucleon-force (3NF) effects. The remarkable advantage of using (p,2p) reaction is that we can choose an appropriate kinematical condition to probe the ... More
Two neutron decay from the $2_1^+$ state of $^6$HeAug 06 2013Decay mode of the $2_1^+$ resonant state of $^6$He populated by the $^6$He breakup reaction by $^{12}$C at 240 MeV/nucleon is investigated. The continuum-discretized coupled-channels method is adopted to describe the formation of the $2_1^+$ state, whereas ... More
Four-body dynamics in 6Li elastic scatteringSep 08 2015We analyze 6Li elastic scattering in a wide range of incident energies (Ein), assuming the n + p + alpha + target four-body model and solving the dynamics with the four-body version of the continuum-discretized coupled-channels method (CDCC). Four-body ... More
Determination of 8B(p,gamma)9C reaction rate from 9C breakupMay 28 2012Aug 02 2012The astrophysical factor of the 8B(p,gamma)9C at zero energy, S18(0), is determined from three-body model analysis of 9C breakup processes. The elastic breakup 208Pb(9C,p8B)208Pb at 65 MeV/nucleon and the one-proton removal reaction of 9C at 285 MeV/nucleon ... More
A Smoothing Method of Discrete Breakup S-matrix Elements in the Theory of Continuum-Discretized Coupled ChannelsFeb 20 2009We present a practical way of smoothing discrete breakup S-matrix elements calculated by the continuum-discretized coupled-channel method (CDCC). This method makes the smoothing procedure much easier. The reliability of the smoothing method is confirmed ... More
Extracting electric dipole breakup cross section of one-neutron halo nuclei from breakup observablesDec 27 2013Jul 25 2014How to extract an electric dipole (E1) breakup cross section \sigma(E1) from one- neutron removal cross sections measured by using 12C and 208Pb targets, \sigma_(-1n)^C and \sigma_(-1n)^Pb, respectively, is discussed. It is shown that within about 5% ... More
Microscopic effective reaction theory for deuteron-induced reactionsJul 21 2016Sep 28 2016The microscopic effective reaction theory is applied to deuteron-induced reactions. A reaction model-space characterized by a $p+n+{\rm A}$ three-body model is adopted, where A is the target nucleus, and the nucleon-target potential is described by a ... More
Large-amplitude quadrupole shape mixing probed by the $(p,p^\prime)$ reaction : a model analysisApr 16 2019To discuss a possible observation of large-amplitude nuclear shape mixing by nuclear reaction, we employ a simple collective model and evaluate transition densities, with which the differential cross sections are obtained through the microscopic coupled-channel ... More
Effective radii of deuteron induced reactionsApr 08 2011The continuum-discretized coupled-channels method (CDCC) for exclusive reactions and the eikonal reaction theory (ERT) as an extension of CDCC to inclusive reactions are applied to deuteron induced reactions. The CDCC result reproduces experimental data ... More
Description of Four-Body Breakup Reaction with the Method of Continuum-Discretized Coupled-ChannelsDec 19 2008May 19 2009We present a method for smoothing discrete breakup $S$-matrix elements calculated by the method of continuum-discretized coupled-channels (CDCC). This smoothing method makes it possible to apply CDCC to four-body breakup reactions. The reliability of ... More
Interplay between the 0+_2 resonance and the nonresonant continuum of the drip-line two-neutron halo nucleus 22COct 01 2012The breakup cross section (BUX) of 22C by 12C at 250 MeV/nucleon is evaluated by the continuum-discretized coupled-channels method incorporating the cluster-orbital shell model (COSM) wave functions. Contributions of the low-lying 0+_2 and 2+_1 resonances ... More
Azimuthal angle distributions of neutrons emitted from the $^9$Be($γ$,$n$) reaction with linearly polarized $γ$-raysMar 30 2018The electromagnetic transitions of $^9$Be with linearly polarized $\gamma$-rays are calculated by using the $\alpha$~+~$\alpha$~+~$n$ three-body model and the complex-scaled solutions of the Lippmann-Schwinger equation; the azimuthal angle distributions ... More
Determination of a dineutron correlation in Borromean nuclei via a quasi-free knockout ($p,pn$) reaction?Mar 12 2016Sep 06 2016To discuss the dineutron correlation in the ground state, the quasi-free neutron knockout reaction on $^6$He is investigated.In the present work, the momentum distribution of the two emitted neutrons is calculated with the $\alpha$~+~$n$~+~$n$ three-body ... More
Excursions through KK modesDec 15 2015Jul 08 2016In this article we study Kaluza-Klein (KK) dimensional reduction of massive Abelian gauge theories with charged matter fields on a circle. Since local gauge transformations change position dependence of the charged fields, the decomposition of the charged ... More
Instantons on Noncommutative R^4 and Projection OperatorsDec 07 1999Feb 10 2000I carefully study noncommutative version of ADHM construction of instantons, which was proposed by Nekrasov and Schwarz. Noncommutative ${\bf R}^4$ is described as algebra of operators acting in Fock space. In ADHM construction of instantons, one looks ... More
Holomorphically Covariant Matrix ModelsJun 21 2004We present a method to construct matrix models on arbitrary simply connected oriented real two dimensional Riemannian manifolds. The actions and the path integral measure are invariant under holomorphic transformations of matrix coordinates.
Dynamical Quark Effects in QCD on the Lattice - results from the CP-PACSSep 22 2000Results of a systematic lattice QCD simulation with two degenerate flavors of sea quarks, identified as dynamical u and d quarks, are presented. The simulation was performed on a dedicated parallel computer, called CP-PACS, developed at the University ... More
Three flavor dynamical QCD project by CP-PACS/JLQCDOct 15 2003The CP-PACS and JLQCD Collaborations have been made systematic studies of lattice QCD carrying out both chiral and continuum extrapolations. Importance of dynamical quark effects has been clarified by a comparison of quenched QCD and two flavor full QCD ... More
Quantum Optical Construction of Generalized Pauli and Walsh-Hadamard Matrices in Three Level SystemsSep 18 2003A set of generators of generalized Pauli matrices play a crucial role in quantum computation based on n level systems of an atom. In this paper we show how to construct them by making use of Rabi oscillations. We also construct the generalized Walsh-Hadamard ... More
A Generalized Hamiltonian Characterizing the Interaction of the Two-Level Atom and both the Single Radiation Mode and External FieldMar 19 2003In this paper we propose some Hamiltonian characterizing the interaction of the two-level atom and both the single radiation mode and external field, which might be a generalization of that of Sch{\"o}n and Cirac (quant-ph/0212068). We solve them in the ... More
Introduction to Grassmann Manifolds and Quantum ComputationMar 04 2001Jul 10 2002Geometrical aspects of quantum computing are reviewed elementarily for non-experts and/or graduate students who are interested in both Geometry and Quantum Computation. In the first half we show how to treat Grassmann manifolds which are very important ... More
Introduction to the Rotating Wave Approximation (RWA) : Two Coherent OscillationsJan 16 2013May 23 2014In this note I introduce a mysterious approximation called the rotating wave approximation (RWA) to undergraduates or non-experts who are interested in both Mathematics and Quantum Optics. In Quantum Optics it plays a very important role in order to obtain ... More
Cavity QED and Quantum Computation in the Strong Coupling RegimeMay 26 2003In this paper we propose a Hamiltonian generalizing the interaction of the two--level atom and both the single radiation mode and external field $...$ a kind of cavity QED. We solve the Schrodinger equation in the strong coupling regime by making use ... More
Geometry of Generalized Coherent States : Some Calculations of Chern CharactersSep 28 2001This is a continuation of the preceding paper (hep-ph/0108219). First of all we make a brief review of generalized coherent states based on Lie algebra su(1,1) and prove that the resolution of unity can be obtained by the curvature form of some bundle. ... More
From Free Fields to AdS -- Thermal CaseMay 17 2005Oct 06 2005We analyze the reorganization of free field theory correlators to closed string amplitudes investigated in hep-th/0308184 hep-th/0402063 hep-th/0409233 hep-th/0504229 in the case of Euclidean thermal field theory and study how the dual bulk geometry is ... More
Dp-D(p+4) in Noncommutative Yang-MillsOct 16 2000Feb 24 2001An anti-self-dual instanton solution in Yang-Mills theory on noncommutative ${\R}^4$ with an anti-self-dual noncommutative parameter is constructed. The solution is constructed by the ADHM construction and it can be treated in the framework of the IIB ... More
Non-Linearly Extended Self-Dual Relations From The Nambu-Bracket Description Of M5-Brane In A Constant C-Field BackgroundJan 13 2010Apr 07 2010The derivation of the self-dual relations for the two-form gauge field in the Nambu-bracket description of M5-brane in a constant C-field background initiated in arXiv:0907.4596 is completed by including contributions from all the fields in the M5-brane ... More
Matrix Model For Polyakov Loops, String Field Theory In The Temporal Gauge, Winding String Condensation In Anti-de Sitter Space And Field Theory Of D-branesJun 30 2008Closed string field theory is constructed by stochastically quantizing a matrix model for Polyakov loops that describes phases of a large N gauge theory at finite temperature. Coherent states in this string field theory describes winding string condensation ... More
Lectures On AdS-CFT At Weak 't Hooft Coupling At Finite TemperatureAug 25 2006Jun 30 2008This is an introductory lecture note aiming at providing an overview of the AdS-CFT correspondence at weak 't Hooft coupling at finite temperature. The first aim of this note is to describe the equivalence of three interesting thermodynamical phenomena ... More
Confined Phase In The Real Time Formalism And The Fate Of The World Behind The HorizonOct 06 2005Feb 18 2006In the real time formulation of finite temperature field theories, one introduces an additional set of fields (type-2 fields) associated to each field in the original theory (type-1 field). In hep-th/0106112, in the context of the AdS-CFT correspondence, ... More
Developments in Finite Temperature QCD on the Lattice with Dynamical QuarksDec 14 1997I report on some recent developments in nonperturbative studies of finite temperature QCD with dynamical quarks on the lattice. I discuss new studies of improved lattice actions and their application to finite temperature QCD. I also summarize the status ... More
Finite Temperature QCD on the LatticeOct 23 1995Recent progress in lattice QCD at finite temperature is reviewed.
Finite Temperature QCD on the Lattice -- Status 2010Dec 20 2010Jan 19 2011In the last couple of years, there has been big progress in finite temperature QCD on the lattice. Large-scale dynamical simulations of 2+1 flavor QCD with various improved staggered quark actions have been started to produce results for various thermodynamic ... More
Elementary Particles on a Dedicated Parallel ComputerDec 06 2001Numerical simulation of lattice QCD is now an indispensable tool for investigating non-perturbative properties of quarks at low energies. In this paper, I introduce a recent lattice QCD calculation of light hadron spectrum and quark masses performed on ... More
Protostellar Collapse with Various MetallicitiesMar 15 2000The thermal and chemical evolution of gravitationally collapsing protostellar clouds is investigated, focusing attention on their dependence on metallicity. Calculations are carried out for a range of metallicities spanning the local interstellar value ... More
Absence of wave operators for one-dimensional quantum walksSep 20 2018We show that there exist pairs of two time evolution operators which do not have wave operators in a context of one-dimensional discrete time quantum walks. As a consequence, the borderline between short range type and long range type is decided.
An Approximate Solution of the Master Equation with the Dissipator being a Set of ProjectorsAug 30 2007In this paper we consider a quantum open system and treat the master equation with some restricted dissipator which consists of a set of projection operators (projectors). The exact solution is given under the commutable approximation (in our terminology). ... More
A Generalization of the Preceding Paper ``A Rabi Oscillation in Four and Five Level Systems"May 16 2006In the preceding paper quant-ph/0312060 we considered a general model of an atom with n energy levels interacting with n-1 external laser fields and constructed a Rabi oscillation in the case of n =3, 4 and 5. In the paper we present a systematic method ... More
A Modern Introduction to Cardano and Ferrari Formulas in the Algebraic EquationsNov 15 2003Nov 26 2003We give a modern approach to the famous Cardano and Ferrari formulas in the algebraic equations with three and four degrees. Namely, we reconstruct these formulas from the point of view of superposition principle in quantum computation based on three ... More
Matrix Elements of Generalized Coherent OperatorsFeb 15 2002Jun 06 2006Explicit forms are given of matrix elements of generalized coherent operators based on Lie algebras su(1,1) and su(2). We also give a kind of factorization formula of the associated Laguerre polynomials.
Mathematical Foundations of Holonomic Quantum Computer IIJan 22 2001This is a sequel to the papers (quant-ph/9910063) and (quant-ph/0004102). The aim of this paper is to give mathematical foundations to Holonomic Quantum Computation (Computer) proposed by Zanardi and Rasetti (quant-ph/9904011) and Pachos and Chountasis ... More
A New Algebraic Structure of Finite Quantum Systems and the Modified Bessel FunctionsApr 14 2007Jul 17 2007In this paper we present a new algebraic structure (a super hyperbolic system in our terminology) for finite quantum systems, which is a generalization of the usual one in the two-level system. It fits into the so-called generalized Pauli matrices, so ... More
Jaynes-Cummings Model and a Non-Commutative "Geometry" : A Few Problems NotedOct 26 2004Nov 11 2004In this paper we point out that the Jaynes-Cummings model without taking a renonance conditon gives a non-commutative version of the simple spin model (including the parameters $x$, $y$ and $z$) treated by M. V. Berry. This model is different from usual ... More
Superluminal Group Velocity of Neutrinos : Review, Development and ProblemsMar 29 2012Apr 05 2012The purpose of this paper is both to provide mathematical reinforcements to the paper [Mecozzi and Bellini : arXiv:1110.1253 [hep-ph]] by taking decoherence into consideration and to present some important problems related. We claim that neutrinos have ... More
SO(4) Re-revisitedNov 07 2011In this note an explicit expression of $\exp A\ (A\in so(4))$ is given in terms of the magic matrix by Makhlin.
Beyond the GaussianDec 11 2009Mar 04 2011In this paper we present a non-Gaussian integral based on a cubic polynomial, instead of a quadratic, and give a fundamental formula in terms of its discriminant. It gives a mathematical reinforcement to the recent result by Morozov and Shakirov. We also ... More
Primordial Star Formation under Far-ultraviolet radiationNov 23 2000Thermal and chemical evolution of primordial gas clouds irradiated with far-ultraviolet (FUV; < 13.6 eV) radiation is investigated. In clouds irradiated by intense FUV radiation, sufficient hydrogen molecules to be important for cooling are never formed. ... More
Large N Reductions and HolographyJun 22 2005Jan 27 2006The large $N$ reductions in gauge theories are identified with dimensional reductions with homogeneous distribution of the eigenvalues of the gauge field, and it is used to identify the corresponding closed string descriptions in the Maldacena duality. ... More
Enhanced nucleon transfer in tip collisions of $^{238}$U+$^{124}$SnAug 09 2017Oct 19 2017Multinucleon transfer processes in low-energy heavy ion reactions have attracted increasing interest in recent years aiming at production of new neutron-rich isotopes. Clearly, it is an imperative task to further develop understanding of underlying reaction ... More
Decoherence and Copenhagen Interpretation : A ScenarioApr 05 2013Dec 18 2014In this paper we give a reasonable explanation (not proof) to the Copenhagen interpretation of Quantum Mechanics from the view point of decoherence theory. Mathematical physicists with strong mission must prove {\bf the Copenhagen interpretation} at all ... More
Exponentiation of certain Matrices related to the Four Level System by use of the Magic MatrixJan 15 2007Aug 30 2007In this paper we show how to calculate explicitly the exponential of certain matrices, which are evolution operators governing the interaction of the four level system of atoms and the radiation, etc. We present a consistent method in terms of the magic ... More
Coherent States and Some Topics in Quantum Information Theory : ReviewJul 31 2002In the first half we make a short review of coherent states and generalized coherent ones based on Lie algebras su(2) and su(1,1), and the Schwinger's boson method to construct representations of the Lie algebras. In the second half we make a review of ... More
Note on Extended Coherent Operators and Some Basic PropertiesSep 28 2000Oct 09 2000This is a continuation of the paper (quant-ph/0009012). In this letter we extend coherent operators and study some basic properties (the disentangling formula, resolution of unity, commutation relation, etc). We also propose a perspective of our work. ... More
Mathematical Foundations of Holonomic Quantum ComputerApr 27 2000We make a brief review of (optical) Holonomic Quantum Computer (or Computation) proposed by Zanardi and Rasetti (quant-ph/9904011) and Pachos and Chountasis (quant-ph/9912093), and give a mathematical reinforcement to their works.
String Solitons in M Theory Fivebrane : A possibility of higher order U(1) bundlesNov 05 1997A volume form $H$ on the $n$--dimensional sphere $S^n$ is closed $(dH=0)$, so that it is locally written as $H=dB$, where B is a $(n-1)$--form. In the first half we give an explicit form to B and, moreover, a speculation concerning higher order U(1) bundles. ... More
A Multidimensional Analogue of the Simpson's Formula of IntegralAug 25 2009The Simpson's formula is obtained by approximating the integral of a function on some interval by the integral of the quadratic polynomial determined by the function. However, a multidimensional analogue of the formula has not been given as far as we ... More
A Geometric Parametrization of the Cabibbo-Kobayashi-Maskawa Matrix and the Jarlskog InvariantJan 15 2009Mar 23 2009In this paper we give a geometric parametrization to the Cabibbo-Kobayashi-Maskawa (CKM) mixing matrix and the Jarlskog invariant, which is based on two flag manifolds $SU(3)/U(1)^{2}$. To treat a fourth generation of quarks on CP violation we generalize ... More