340 results on '"Kazuo Fujikawa"'
Search Results
2. Supplemental Figures 1-7 from Bacterial SOS Genes mucAB/umuDC Promote Mouse Tumors by Activating Oncogenes Nedd9/Aurkb via a miR-145 Sponge
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Takahiro Ochiya, Hiroki Sasaki, Kazuhiko Aoyagi, Fumiko Chiwaki, Masamichi Ishiai, Tetsuji Nagao, Kazuo Fujikawa, Kouichi Tatsumi, Ryou-u Takahashi, Ayako Inoue, and Hiroshi Tanooka
- Abstract
Supplementary Fig. S1. Nedd9 and Aurkb seed match sequences in mucAB and umuDC.Supplementary Fig. S2. Selection of cells expressing Tet-repressor protein.Supplementary Fig. S3. Microarray analysis of deregulated oncogenes.Supplementary Fig. S4. Suppression of cellular transformation with anti-mucAB shRNA.Supplementary Fig. S5. Confirmation of interaction of miR-145 with anti-miR-145.Supplementary Fig. S6. Microcolony formation over time.Supplementary Fig. S7. Comparison of tumor incidence rates between males and females, and between presence and absence of Zn.
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- 2023
3. KK and a Nice Memory of the Emergent Singapore
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Kazuo Fujikawa
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- 2022
4. Path-integral derivation of the equations of the anomalous Hall effect
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Kazuo Fujikawa and Koichiro Umetsu
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- 2022
5. Berry's phase and chiral anomalies
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Kazuo Fujikawa and Koichiro Umetsu
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High Energy Physics - Theory ,Nuclear Theory (nucl-th) ,Nuclear and High Energy Physics ,Nuclear Theory ,High Energy Physics - Theory (hep-th) ,FOS: Physical sciences - Abstract
The basic materials of Berry's phase and chiral anomalies are presented to appreciate the phenomena related to those notions. As for Berry's phase, a general survey of the subject is presented using both Lagrangian and Hamiltonian formalisms. The canonical Hamiltonian formalism of the Born-Oppenheimer approximation, when applied to the anomalous Hall effect, can incorporate the gauge symmetry of Berry's connection but unable to incorporate the electromagnetic vector potential simultaneously. Transformed to the Lagrangian formalism with a time-derivative term allowed, the Born-Oppenheimer approximation can incorporate the electromagnetic vector potential simultaneously with Berry's connection, but the consistent canonical property is lost and thus becomes classical. The Lagrangian formalism can thus incorporate both gauge symmetries simultaneously but spoils the basic quantum symmetries, and thus results in classical anomalous Poisson brackets and the classical Nernst effect as in the conventional formalism. As for chiral anomalies, we present basic materials by the path integral formulation with an emphasis on fermions on the lattice. A chiral fermion defined by $\gamma_{5}$ on the lattice does not contain the chiral anomaly for the non-vanishing lattice spacing $a\neq0$. The idea of a spectral flow on the lattice does not lead to an anomaly for each species doubler separately but rather to a pair production in a general sense. We also mention that a specific construction called the Ginsparg-Wilson fermion, which is free of species doublers, may practically be useful. We discuss the representative applications of Berry's phase and chiral anomalies in nuclear physics and related fields to illustrate the use of these two basic notions., Comment: 126 pages. 10 figures. Corrected typos and a poorly organized page in Appendix B, together with a new reference
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- 2022
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6. Bacterial SOS Genes mucAB/umuDC Promote Mouse Tumors by Activating Oncogenes Nedd9/Aurkb via a miR-145 Sponge
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Kazuhiko Aoyagi, Kouichi Tatsumi, Ryou-u Takahashi, Takahiro Ochiya, Masamichi Ishiai, Hiroshi Tanooka, Fumiko Chiwaki, Ayako Inoue, Tetsuji Nagao, Hiroki Sasaki, and Kazuo Fujikawa
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0301 basic medicine ,Genetically modified mouse ,Cancer Research ,Oncogene ,Biology ,medicine.disease_cause ,Cell biology ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,Plasmid ,Oncology ,RNA interference ,030220 oncology & carcinogenesis ,microRNA ,medicine ,Cancer research ,Mutation frequency ,Carcinogenesis ,Molecular Biology ,Gene - Abstract
The mechanism of cancer induction involves an aberrant expression of oncogenes whose functions can be controlled by RNAi with miRNA. Even foreign bacterial RNA may interfere with the expression of oncogenes. Here we show that bacterial plasmid mucAB and its Escherichia coli genomic homolog umuDC, carrying homologies that match the mouse anti-miR-145, sequestered the miR-145 function in mouse BALB 3T3 cells in a tetracycline (Tet)-inducible manner, activated oncogene Nedd9 and its downstream Aurkb, and further enhanced microcolony formation and cellular transformation as well as the short fragments of the bacterial gene containing the anti-miR-145 sequence. Furthermore, mucAB transgenic mice showed a 1.7-fold elevated tumor incidence compared with wild-type mice after treatments with 3-methylcolanthrene. However, the mutation frequency in intestinal stem cells of the mucAB transgenic mice was unchanged after treatment with X-rays or ethyl-nitrosourea, indicating that the target of mucAB/umuDC is the promotion stage in carcinogenesis. Implications: Foreign bacterial genes can exert oncogenic activity via RNAi, if endogenously expressed. Visual Overview: http://mcr.aacrjournals.org/content/molcanres/18/9/1271/F1.large.jpg.
- Published
- 2020
7. Lensing of Dirac monopole in Berry's phase
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Koichiro Umetsu and Kazuo Fujikawa
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Physics ,High Energy Physics - Theory ,Strongly Correlated Electrons (cond-mat.str-el) ,Nuclear Theory ,Magnetic monopole ,Phase (waves) ,FOS: Physical sciences ,Parameter space ,Level crossing ,Magnetic flux ,Magnetic field ,Nuclear Theory (nucl-th) ,Dipole ,Condensed Matter - Strongly Correlated Electrons ,High Energy Physics - Theory (hep-th) ,Quantum electrodynamics ,Adiabatic process - Abstract
Berry's phase, which is associated with the slow cyclic motion with a finite period, looks like a Dirac monopole when seen from far away but smoothly changes to a dipole near the level crossing point in the parameter space in an exactly solvable model. This topology change of Berry's phase is visualized as a result of lensing effect; the monopole supposed to be located at the level crossing point appears at the displaced point when the variables of the model deviate from the precisely adiabatic movement. The effective magnetic field generated by Berry's phase is determined by a simple geometrical consideration of the magnetic flux coming from the displaced Dirac monopole., 14 pages, 4 figures. The agreement of Berry's phase with the solid angle drawn by a spin vector in the case of a two-component spinor is explained in connection with the lensing effect. This version is going to appear in Phys. Rev. D
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- 2021
8. Parity and CP operations for Majorana neutrinos
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Kazuo Fujikawa
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High Energy Physics - Theory ,Physics ,Particle physics ,Fermionic field ,010308 nuclear & particles physics ,High Energy Physics::Phenomenology ,FOS: Physical sciences ,Parity (physics) ,Fermion ,01 natural sciences ,High Energy Physics - Phenomenology ,symbols.namesake ,MAJORANA ,High Energy Physics - Phenomenology (hep-ph) ,High Energy Physics - Theory (hep-th) ,0103 physical sciences ,symbols ,High Energy Physics::Experiment ,Neutrino ,010306 general physics ,Majorana fermion - Abstract
The parity transformation law of the fermion field $\psi(x)$ is usually defined by the "$\gamma^{0}$-parity" $\psi^{p}(t,-\vec{x}) = \gamma^{0}\psi(t,-\vec{x})$ with eigenvalues $\pm 1$, while the "$i\gamma^{0}$-parity" $\psi^{p}(t,-\vec{x})=i\gamma^{0}\psi(t,-\vec{x})$ is required for the Majorana fermion. The compatibility issues of these two parity laws arise in generic fermion number violating theories where a general class of Majorana fermions appear. In the case of Majorana neutrinos constructed from chiral neutrinos in an extension of the Standard Model, the Majorana neutrinos can be characterized by CP symmetry although C and P are separately broken. It is then shown that either choice of the parity operation, $\gamma^{0}$ or $i\gamma^{0}$, in the level of the starting fermions gives rise to the consistent and physically equivalent descriptions of emergent Majorana neutrinos both for Weinberg's model of neutrinos and for a general class of seesaw models. The mechanism of this equivalence is that the Majorana neutrino constructed from a chiral neutrino, which satisfies the classical Majorana condition $\psi(x)=C\overline{\psi(x)}^{T}$, allows the phase freedom $\psi(x)=e^{i\alpha}\nu_{L}(x) + e^{-i\alpha}C\overline{\nu_{L}(x)}^{T}$ with $\alpha=0\ {\rm or}\ \pi/4$ that accounts for the phase coming from the different definitions of parity for $\nu_{L}(x)$ and ensures the consistent definitions of CP symmetry $({\cal CP})\psi(x)({\cal CP})^{\dagger}= \pm i\gamma^{0}\psi(t,-\vec{x})$., Comment: 24 pages. Substantially modified including title and abstract. Added an extensive appendix. This version is to appear in Phys. Rev. D
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- 2020
9. Parity of the neutron consistent with neutron-antineutron oscillations
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Kazuo Fujikawa, Anca Tureanu, and Department of Physics
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Physics ,High Energy Physics - Theory ,Particle physics ,VIOLATION ,010308 nuclear & particles physics ,Astrophysics::High Energy Astrophysical Phenomena ,High Energy Physics::Phenomenology ,CONSERVATION ,Nuclear Theory ,FOS: Physical sciences ,Parity (physics) ,Antineutron ,MAJORANA NEUTRINOS ,01 natural sciences ,114 Physical sciences ,MAJORANA ,High Energy Physics - Phenomenology ,High Energy Physics - Phenomenology (hep-ph) ,High Energy Physics - Theory (hep-th) ,0103 physical sciences ,Neutron ,010306 general physics ,Nuclear Experiment - Abstract
In the analysis of neutron-antineutron oscillations, it has been recently argued in the literature that the use of the $i\gamma^{0}$ parity $n^{p}(t,-\vec{x})=i\gamma^{0}n(t,-\vec{x})$ which is consistent with the Majorana condition is mandatory and that the ordinary parity transformation of the neutron field $n^{p}(t,-\vec{x}) = \gamma^{0}n(t,-\vec{x})$ has a difficulty. We show that a careful treatment of the ordinary parity transformation of the neutron works in the analysis of neutron-antineutron oscillations. Technically, the CP symmetry in the mass diagonalization procedure is important and the two parity transformations, $i\gamma^{0}$ parity and $\gamma^{0}$ parity, are compensated for by the Pauli-G\"ursey transformation. Our analysis shows that either choice of the parity gives the correct results of neutron-antineutron oscillations if carefully treated., Comment: 19 pages. Some modifications in Appendix B were made. This version is going to be published in Phys. Rev. D
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- 2020
10. Bacterial SOS Genes
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Hiroshi, Tanooka, Ayako, Inoue, Ryou-U, Takahashi, Kouichi, Tatsumi, Kazuo, Fujikawa, Tetsuji, Nagao, Masamichi, Ishiai, Fumiko, Chiwaki, Kazuhiko, Aoyagi, Hiroki, Sasaki, and Takahiro, Ochiya
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Transcriptional Activation ,BALB 3T3 Cells ,Escherichia coli Proteins ,DNA-Directed DNA Polymerase ,Neoplasms, Experimental ,Oncogenes ,Mice ,MicroRNAs ,Cell Transformation, Neoplastic ,Genes, Bacterial ,Cell Line, Tumor ,Animals ,Aurora Kinase B ,Adaptor Proteins, Signal Transducing - Abstract
The mechanism of cancer induction involves an aberrant expression of oncogenes whose functions can be controlled by RNAi with miRNA. Even foreign bacterial RNA may interfere with the expression of oncogenes. Here we show that bacterial plasmid
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- 2020
11. Operatorial characterization of Majorana neutrinos
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Kazuo Fujikawa
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High Energy Physics - Theory ,Particle physics ,Physics and Astronomy (miscellaneous) ,High Energy Physics::Lattice ,FOS: Physical sciences ,lcsh:Astrophysics ,Type (model theory) ,01 natural sciences ,High Energy Physics - Phenomenology (hep-ph) ,Double beta decay ,lcsh:QB460-466 ,0103 physical sciences ,lcsh:Nuclear and particle physics. Atomic energy. Radioactivity ,010306 general physics ,Engineering (miscellaneous) ,Physics ,C-symmetry ,010308 nuclear & particles physics ,High Energy Physics::Phenomenology ,Charge (physics) ,Fermion ,MAJORANA ,High Energy Physics - Phenomenology ,High Energy Physics - Theory (hep-th) ,lcsh:QC770-798 ,CP violation ,Neutrino - Abstract
The Majorana neutrino $\psi_{M}(x)$ when constructed as a superposition of chiral fermions such as $\nu_{L} + C\overline{\nu_{L}}^{T}$ is characterized by $ ({\cal C}{\cal P}) \psi_{M}(x)({\cal C}{\cal P})^{\dagger} =i\gamma^{0}\psi_{M}(t,-\vec{x})$, and the CP symmetry describes the entire physics contents of Majorana neutrinos. Further specifications of C and P separately could lead to difficulties depending on the choice of C and P. The conventional $ {\cal C} \psi_{M}(x) {\cal C}^{\dagger} = \psi_{M}(x)$ with well-defined P is naturally defined when one constructs the Majorana neutrino from the Dirac-type fermion. In the seesaw model of Type I or Type I+II where the same number of left- and right-handed chiral fermions appear, it is possible to use the generalized Pauli-Gursey transformation to rewrite the seesaw Lagrangian in terms of Dirac-type fermions only; the conventional C symmetry then works to define Majorana neutrinos. In contrast, the "pseudo C-symmetry" $\nu_{L,R}(x)\rightarrow C\overline{\nu_{L,R}(x)}^{T}$ (and associated "pseudo P-symmetry"), that has been often used in both the seesaw model and Weinberg's model to describe Majorana neutrinos, attempts to assign a nontrivial charge conjugation transformation rule to each chiral fermion separately. But this common construction is known to be operatorially ill-defined and, for example, the amplitude of the neutrinoless double beta decay vanishes if the vacuum is assumed to be invariant under the pseudo C-symmetry., Comment: 25 pages. Substantially expanded to explain the subject in more detail. This version is to be published in European Physical Journal C
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- 2019
12. Neutron Oscillations and the Parity Doubling Theorem
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Kazuo Fujikawa, Anca Tureanu, and Department of Physics
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Physics ,Physics and Astronomy (miscellaneous) ,Oscillation ,General Mathematics ,Nuclear Theory ,Observable ,Parity (physics) ,Computer Science::Digital Libraries ,114 Physical sciences ,Symmetry (physics) ,Baryon ,Electric dipole moment ,CP violation ,Parity of majorana fermions ,Chemistry (miscellaneous) ,Quantum electrodynamics ,Neutron-antineutron oscillations ,QA1-939 ,Computer Science (miscellaneous) ,Computer Science::Programming Languages ,Neutron ,Nuclear Experiment ,Mathematics - Abstract
We review several aspects of parity and CP violation in the framework of neutron-antineutron oscillations. We focus on the parity doubling theorem, which provides a criterion for neutron oscillation in the general theory with ΔB=2 baryon number-violating interactions. We prove by explicit calculations that the violation of the conventional parity symmetry with P2=1 is the necessary condition for neutron oscillations to happen. While the CP violation is not manifest in the oscillation, it is nevertheless intrinsic to the system, and it is transferred, by the mixing matrix, to the neutron interactions and potentially observable as a contribution to the electric dipole moment.
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- 2021
13. Majorana neutrino as Bogoliubov quasiparticle
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Kazuo Fujikawa, Anca Tureanu, and Department of Physics
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High Energy Physics - Theory ,Nuclear and High Energy Physics ,Sterile neutrino ,Particle physics ,Helical Dirac fermion ,High Energy Physics::Lattice ,FOS: Physical sciences ,114 Physical sciences ,01 natural sciences ,Superconductivity (cond-mat.supr-con) ,symbols.namesake ,High Energy Physics - Phenomenology (hep-ph) ,0103 physical sciences ,OSCILLATIONS ,010306 general physics ,Majorana equation ,Physics ,Condensed Matter::Quantum Gases ,010308 nuclear & particles physics ,Condensed Matter - Superconductivity ,High Energy Physics::Phenomenology ,Fermion ,Physics::History of Physics ,lcsh:QC1-999 ,High Energy Physics - Phenomenology ,Bogoliubov transformation ,MAJORANA ,Dirac fermion ,High Energy Physics - Theory (hep-th) ,symbols ,lcsh:Physics ,Majorana fermion - Abstract
We suggest that the Majorana neutrino should be regarded as a Bogoliubov quasiparticle that is consistently understood only by use of a relativistic analogue of the Bogoliubov transformation. The unitary charge conjugation condition ${\cal C}\psi{\cal C}^{\dagger}=\psi$ is not maintained in the definition of a quantum Majorana fermion from a Weyl fermion. This is remedied by the Bogoliubov transformation accompanying a redefinition of the charge conjugation properties of vacuum, such that a C-noninvariant fermion number violating term (condensate) is converted to a Dirac mass. We also comment on the chiral symmetry of a Majorana fermion; a massless Majorana fermion is invariant under a global chiral transformation $\psi\rightarrow \exp[i\alpha\gamma_{5}]\psi$ and different Majorana fermions are distinguished by different chiral $U(1)$ charge assignments. The reversed process, namely, the definition of a Weyl fermion from a well-defined massless Majorana fermion is also briefly discussed., Comment: 15 pages; correction of the formula after eq. (6), in the version published in Phys. Lett. B
- Published
- 2017
14. Measurement of the gamma-ray energy spectrum of the educational Kinki University Reactor (UTR-KINKI)
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Tsuyoshi Kajimoto, Masashi Takada, Tatsuro Taniguchi, Kazuo Fujikawa, Satoru Endo, Kenichi Tanaka, Tetsuo Horiguchi, and So Kamada
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Physics ,Nuclear fission product ,Radiation ,Fission ,Astrophysics::High Energy Astrophysical Phenomena ,Monte Carlo method ,Gamma ray ,Proportional counter ,030218 nuclear medicine & medical imaging ,Nuclear physics ,03 medical and health sciences ,Kerma ,0302 clinical medicine ,030220 oncology & carcinogenesis ,Ionization ,Irradiation - Abstract
The gamma-ray energy spectrum of the Kinki University Reactor (UTR-KINKI) was estimated from Ge detector measurements combined with Monte Carlo N-particle transport criticality calculations. The gamma rays mainly originated from prompt fission components, although small amounts of gamma rays from (n,γ) reactions, fission product gamma rays, and activation gamma rays were detected. The averaged gamma-ray tissue kerma rate in the irradiation port during UTR-KINKI operation at 1W was calculated as 10.5cGy/h based on the estimated gamma-ray energy spectrum. This value is consistent with a previous measurement with paired ionization chambers and a tissue equivalent gas proportional counter. This result demonstrates the reliability of the estimated gamma-ray energy spectrum.
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- 2017
15. No anomalous canonical commutators induced by Berry’s phase
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Kazuo Fujikawa and Shinichi Deguchi
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High Energy Physics - Theory ,Magnetic monopole ,FOS: Physical sciences ,General Physics and Astronomy ,Position and momentum space ,01 natural sciences ,law.invention ,Poisson bracket ,High Energy Physics - Phenomenology (hep-ph) ,Singularity ,law ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,0103 physical sciences ,010306 general physics ,Adiabatic process ,Mathematical physics ,Physics ,Condensed Matter - Mesoscale and Nanoscale Physics ,010308 nuclear & particles physics ,Dirac (video compression format) ,Order (ring theory) ,Commutator (electric) ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,Nonlinear Sciences::Chaotic Dynamics ,High Energy Physics - Phenomenology ,High Energy Physics - Theory (hep-th) - Abstract
The monopole-like singularity of Berry's adiabatic phase in momentum space and associated anomalous Poisson brackets have been recently discussed in various fields. With the help of the results of an exactly solvable version of Berry's model, we show that Berry's phase does not lead to the deformation of the principle of quantum mechanics in the sense of anomalous canonical commutators. If one should assume Berry's phase of genuine Dirac monopole-type, which is assumed to hold not only in the adiabatic limit but also in the non-adiabatic limit, the deformation of the principle of quantum mechanics could take place. But Berry's phase of the genuine Dirac monopole-type is not supported by the exactly solvable version of Berry's model nor by a generic model of Berry's phase. Besides, the monopole-like Berry's phase in momentum space has a magnetic charge $e_{M}=2\pi\hbar$, for which the possible anomalous term in the canonical commutator $[x_{k},x_{l}]=i\hbar\Omega_{kl}$ would become of the order $O(\hbar^{2})$., Comment: 29 pages and 3 figures. Substantially expanded and a detailed account of the absence of no anomalous cononical commutators induced by Berry's phase is given. The title has also been changed accordingly. This version is to be published in Ann. of Phys
- Published
- 2020
16. A classical limit of Grover's algorithm induced by dephasing: Coherence vs entanglement
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Choo Hiap Oh, Kazuo Fujikawa, and Koichiro Umetsu
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Physics ,Nuclear and High Energy Physics ,Quantum Physics ,Dephasing ,FOS: Physical sciences ,General Physics and Astronomy ,Astronomy and Astrophysics ,02 engineering and technology ,Quantum entanglement ,021001 nanoscience & nanotechnology ,01 natural sciences ,Classical limit ,Quantum state ,Quantum mechanics ,Qubit ,0103 physical sciences ,Grover's algorithm ,Quantum Physics (quant-ph) ,010306 general physics ,0210 nano-technology ,Quantum ,Quantum computer - Abstract
A new approach to the classical limit of Grover's algorithm is discussed by assuming a very rapid dephasing of a system between consecutive Grover's unitary operations, which drives pure quantum states to decohered mixed states. One can identify a specific element among $N$ unsorted elements by a probability of the order of unity after $k\sim N$ steps of classical amplification, which is realized by a combination of Grover's unitary operation and rapid dephasing, in contrast to $k\sim \pi \sqrt{N}/4$ steps in quantum mechanical amplification. The initial two-state system with enormously unbalanced existence probabilities, which is realized by a chosen specific state and a superposition of all the rest of states among $N$ unsorted states, is crucial in the present analysis of classical amplification. This analysis illustrates Grover's algorithm in extremely noisy circumstances. A similar increase from $k\sim \sqrt{N}$ to $k\sim N$ steps due to the loss of quantum coherence takes place in the {\em analog} model of Farhi and Gutmann where the entanglement does not play an obvious role. This supports a view that entanglement is crucial in quantum computation to describe quantum states by a set of qubits, but the actual speedup of the quantum computation is based on quantum coherence., Comment: 15 pages. Substantially modified with an additional author and the change of the title. This version is going to be published in Mod. Phys. Lett. A
- Published
- 2018
17. Majorana neutrinos in the seesaw mechanism and Bogoliubov quasiparticles
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Kazuo Fujikawa, Anca Tureanu, and Department of Physics
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High Energy Physics - Theory ,Sterile neutrino ,Particle physics ,VIOLATION ,Physics beyond the Standard Model ,High Energy Physics::Lattice ,CONSERVATION ,MODELS ,FOS: Physical sciences ,01 natural sciences ,114 Physical sciences ,NUMBER ,High Energy Physics - Phenomenology (hep-ph) ,0103 physical sciences ,OSCILLATIONS ,010306 general physics ,MASSES ,Majorana equation ,Physics ,Condensed Matter::Quantum Gases ,010308 nuclear & particles physics ,High Energy Physics::Phenomenology ,Fermion ,High Energy Physics - Phenomenology ,Bogoliubov transformation ,MAJORANA ,Seesaw mechanism ,High Energy Physics - Theory (hep-th) ,MIXINGS ,Neutrino ,CHARGE - Abstract
The idea that the Majorana neutrino should be identified as a Bogoliubov quasiparticle is applied to the seesaw mechanism for the three generations of neutrinos in the Standard Model. A relativistic analogue of the Bogoliubov transformation in the present context is a CP-preserving canonical transformation but modifies charge conjugation properties in such a way that the C-noninvariant fermion number violating term (condensate) is converted to a Dirac mass term. Puzzling aspects associated with the charge conjugation of chiral Weyl fermions are clarified. By invoking the Coleman--Weinberg mechanism in the framework of dimensional regularization, it is also noted that seesaw models become unnatural in some parameter regions which induce the hierarchy problems in the bosonic sector., Comment: 20 pages
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- 2018
18. Baryon number violation and novel canonical anti-commutation relations
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Anca Tureanu, Kazuo Fujikawa, and Department of Physics
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High Energy Physics - Theory ,Nuclear and High Energy Physics ,Particle physics ,Canonical quantization ,Nuclear Theory ,FOS: Physical sciences ,Computer Science::Digital Libraries ,01 natural sciences ,114 Physical sciences ,High Energy Physics - Phenomenology (hep-ph) ,0103 physical sciences ,Nuclear Experiment ,010306 general physics ,Mathematical physics ,Physics ,010308 nuclear & particles physics ,Degenerate energy levels ,High Energy Physics::Phenomenology ,Equations of motion ,Fermion ,NEUTRON OSCILLATIONS ,BCS theory ,16. Peace & justice ,lcsh:QC1-999 ,High Energy Physics - Phenomenology ,MAJORANA ,Bogoliubov transformation ,High Energy Physics - Theory (hep-th) ,Baryon number ,lcsh:Physics - Abstract
The possible neutron-antineutron oscillation is described by an effective quadratic Lagrangian analogous to the BCS theory. It is shown that the conventional equal-time anti-commutation relations of the neutron variable $n(t,\vec{x})$ are modified by the baryon number violating terms. This is established by the Bjorken--Johnson--Low prescription and also by the canonical quantization combined with equations of motion. This novel canonical behavior can give rise to an important physical effect, which is illustrated by analyzing the Lagrangian that violates the baryon number but gives rise to the degenerate effective Majorana fermions and thus no neutron-antineutron oscillation. Technically, this model is neatly treated using a relativistic analogue of the Bogoliubov transformation., Comment: 14 pages
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- 2018
19. Majorana neutrino and the vacuum of Bogoliubov quasiparticle
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Kazuo Fujikawa
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High Energy Physics - Theory ,Nuclear and High Energy Physics ,Nuclear Theory ,FOS: Physical sciences ,01 natural sciences ,High Energy Physics - Phenomenology (hep-ph) ,Condensed Matter::Superconductivity ,0103 physical sciences ,010306 general physics ,Mathematical physics ,Physics ,Condensed Matter::Quantum Gases ,010308 nuclear & particles physics ,Condensed Matter::Other ,High Energy Physics::Phenomenology ,BCS theory ,lcsh:QC1-999 ,MAJORANA ,Bogoliubov transformation ,High Energy Physics - Phenomenology ,Seesaw mechanism ,High Energy Physics - Theory (hep-th) ,Quasiparticle ,Neutrino ,Nucleon ,Chiral symmetry breaking ,lcsh:Physics - Abstract
The Lagrangian of the seesaw mechanism is C violating but the same Lagrangian when re-written in terms of Majorana neutrinos is manifestly C invariant. To resolve this puzzling feature, a relativistic analogue of Bogoliubov transformation, which preserves CP but explicitly breaks C and P separately, was introduced together with the notions of a Bogoliubov quasiparticle and an analogue of the energy gap in BCS theory. The idea of Majorana neutrino as Bogoliubov quasiparticle was then suggested. In this paper, we study the vacuum structure of the Bogoliubov quasiparticle which becomes heavy by absorbing the C-breaking. By treating an infinitesimally small C violating term as an analogue of the chiral symmetry breaking nucleon mass in the model of Nambu and Jona-Lasinio, we construct an explicit form of the vacuum of the Bogoliubov quasiparticle which defines Majorana neutrinos in seesaw mechanism. The vacuum of the Bogoliubov quasiparticle thus constructed has an analogous condensate structure as the vacuum of the quasiparticle (nucleon) in the Nambu--Jona-Lasinio model., Comment: 17 pages. Some typos were corrected, and clarifying comments were added. This version is to appear in PLB
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- 2018
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20. Generalized Pauli-Gursey transformation and Majorana neutrinos
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Kazuo Fujikawa
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Physics ,High Energy Physics - Theory ,Nuclear and High Energy Physics ,Antiparticle ,C-symmetry ,010308 nuclear & particles physics ,Physics beyond the Standard Model ,High Energy Physics::Phenomenology ,FOS: Physical sciences ,Fermion ,01 natural sciences ,lcsh:QC1-999 ,MAJORANA ,Theoretical physics ,symbols.namesake ,High Energy Physics - Phenomenology ,Pauli exclusion principle ,High Energy Physics - Phenomenology (hep-ph) ,Seesaw molecular geometry ,High Energy Physics - Theory (hep-th) ,0103 physical sciences ,symbols ,Neutrino ,010306 general physics ,lcsh:Physics - Abstract
We discuss a generalization of the Pauli-Gursey transformation, which is motivated by the Autonne-Takagi factorization, to an arbitrary $n$ number of generations of neutrinos using $U(2n)$ that defines general canonical transformations and diagonalizes symmetric complex Majorana mass matrices in special cases. The Pauli-Gursey transformation mixes particles and antiparticles and thus changes the definition of the vacuum and C. We define C, P and CP symmetries at each Pauli frame specified by a generalized Pauli-Gursey transformation. The Majorana neutrinos in the C and P violating seesaw model are then naturally defined by a suitable choice of the Pauli frame, where only Dirac-type fermions appear with well-defined C, P and CP, and thus the C symmetry for Majorana neutrinos agrees with the C symmetry for Dirac-type fermions. This fully symmetric setting corresponds to the idea of Majorana neutrinos as Bogoliubov quasi-particles. In contrast, the conventional direct construction of Majorana neutrinos in the seesaw model, where CP is well-defined but C and P are violated, encounters the mismatch of C symmetry for Majorana neutrinos and C symmetry for chiral fermions; this mismatch is recognized as the inevitable appearance of the singlet (trivial) representation of C symmetry for chiral fermions., Comment: 15 pages. Slightly expanded with some explanatory paragraphs added. This version is going to appear in Phys.Lett. B
- Published
- 2018
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21. Seesaw mechanism and pseudo C-symmetry
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Kazuo Fujikawa, Anca Tureanu, Department of Physics, and Particle Physics and Astrophysics
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Quark ,High Energy Physics - Theory ,Physics and Astronomy (miscellaneous) ,FOS: Physical sciences ,lcsh:Astrophysics ,01 natural sciences ,114 Physical sciences ,Computer Science::Digital Libraries ,High Energy Physics - Phenomenology (hep-ph) ,Seesaw molecular geometry ,0103 physical sciences ,lcsh:QB460-466 ,lcsh:Nuclear and particle physics. Atomic energy. Radioactivity ,010306 general physics ,Engineering (miscellaneous) ,Mathematical physics ,Physics ,C-symmetry ,010308 nuclear & particles physics ,High Energy Physics::Phenomenology ,Fermion ,Bogoliubov transformation ,MAJORANA ,High Energy Physics - Phenomenology ,Seesaw mechanism ,High Energy Physics - Theory (hep-th) ,CP violation ,lcsh:QC770-798 - Abstract
It is shown that the specific "charge conjugation" transformation used to define the Majorana fermions in the conventional seesaw mechanism, namely $(\nu_{R})^{C}=C\bar{\nu_{R}}^{T}$ for a chiral fermion $\nu_{R}$ (and similarly for $\nu_{L}$), is a hidden symmetry associated with CP symmetry, and thus it formally holds independently of the P- and C-violating terms in the CP invariant Lagrangian and it is in principle applicable to charged leptons and quarks as well. This hidden symmetry, however, is not supported by a consistent unitary operator and thus it leads to mathematical (operatorial) ambiguities. When carefully examined, it also fails as a classical transformation law in a Lorentz invariant field theory. To distinguish it from the standard charge conjugation symmetry, we suggest for it the name of pseudo C-symmetry. The pseudo C-symmetry is effective to identify Majorana neutrinos analogously to the classical Majorana condition. The analysis of CP breaking in weak interactions is performed using the conventional CP transformation, which is defined independently of the pseudo C-transformation, in the seesaw model after mass diagonalization. A way to ensure an operatorially consistent formulation of C-conjugation is to formulate the seesaw scheme by invoking a relativistic analogue of the Bogoliubov transformation., Comment: 16 pages. Some modifications in Abstract and in the body of the manuscript. This version is going to appear in European Physical Journal C
- Published
- 2018
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22. Lorentz Invariant CPT Breaking in the Dirac Equation
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Kazuo Fujikawa
- Published
- 2017
23. Characteristics of Chiral Anomaly in View of Various Applications
- Author
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Kazuo Fujikawa
- Subjects
High Energy Physics - Theory ,Nuclear Theory ,Conformal anomaly ,High Energy Physics::Lattice ,Mixed anomaly ,FOS: Physical sciences ,Computer Science::Digital Libraries ,01 natural sciences ,Nuclear Theory (nucl-th) ,symbols.namesake ,Quantum mechanics ,0103 physical sciences ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,010306 general physics ,Dirac sea ,Gauge anomaly ,Mathematical physics ,Chiral anomaly ,Physics ,Condensed Matter - Mesoscale and Nanoscale Physics ,010308 nuclear & particles physics ,High Energy Physics::Phenomenology ,Global anomaly ,Fermion ,Geometric phase ,High Energy Physics - Theory (hep-th) ,symbols - Abstract
In view of the recent applications of chiral anomaly to various fields beyond particle physics, we discuss some basic aspects of chiral anomaly which may help deepen our understanding of chiral anomaly in particle physics also. It is first shown that Berry's phase (and its generalization) for the Weyl model $H =v_{F} \vec{\sigma}\cdot \vec{p}(t)$ assumes a monopole form at the exact adiabatic limit but deviates from it off the adiabatic limit and vanishes in the high frequency limit of the Fourier transform of $\vec{p}(t)$ for bounded $|\vec{p}(t)|$. An effective action, which is consistent with the non-adiabatic limit of Berry's phase, combined with the Bjorken-Johnson-Low prescription gives normal equal-time space-time commutators and no chiral anomaly. In contrast, an effective action with a monopole at the origin of the momentum space, which describes Berry's phase in the precise adiabatic limit but fails off the adiabatic limit, gives anomalous space-time commutators and a covariant anomaly to the gauge current. We regard this anomaly as an artifact of the postulated monopole and not a consequence of Berry's phase. As for the recent application of the chiral anomaly to the description of effective Weyl fermions in condensed matter and nuclear physics, which is closely related to the formulation of lattice chiral fermions, we point out that the chiral anomaly for each species doubler separately vanishes for a finite lattice spacing, contrary to the common assumption. Instead a general form of pair creation associated with the spectral flow for the Dirac sea with finite depth takes place. This view is supported by the Ginsparg-Wilson fermion, which defines a single Weyl fermion without doublers on the lattice and gives a well-defined index (anomaly) even for a finite lattice spacing., Comment: 14 pages. Some explanations are added. This version is to be published in PRD
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- 2017
- Full Text
- View/download PDF
24. Frequency and size of micronuclei induced in gill cells of medaka fish (Oryzias latipes) after whole-body exposure to clastogenic chemicals
- Author
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Masahiro Nakagawa, Nao Kagawa, Kazuo Fujikawa, Akinori Takai, and Yumi Watabe
- Subjects
Gills ,Gill ,Health, Toxicology and Mutagenesis ,Oryzias ,Biology ,Toxicology ,Andrology ,chemistry.chemical_compound ,Clastogen ,Animals ,Colchicine ,Cells, Cultured ,Micronuclei, Chromosome-Defective ,Pharmacology ,Micronucleus Tests ,Chemical Health and Safety ,Dose-Response Relationship, Drug ,X-Rays ,Mitomycin C ,Public Health, Environmental and Occupational Health ,General Medicine ,biology.organism_classification ,chemistry ,Cell Nucleus Size ,Micronucleus test ,%22">Fish ,Micronucleus ,Mutagens - Abstract
Medaka fish (Oryzias latipes) were whole-bodily treated with various doses of mitomycin C (MMC), ethylmethanesulfonate (EMS), cyclophosphamide (CP), diethylnitrosamine (DEN), or colchicine (COL) for 24 h, and the frequency of micronucleated cells (MNCs) was measured in the gills at 24 and 48 h after treatment. In the present experiments, MMC, CP, and DEN were recorded as efficient inducers of micronuclei at both sampling times, and none of the MNC frequencies recorded with these agents at 24 h significantly exceeded the corresponding frequency at 48 h. For EMS and COL, positive responses were recorded only 48 h after treatment. By comparison with the time-course data reported for radiation-induced MNCs in the same MN assay system, the clear responses observed at the 48-h time point for all the chemicals used were regarded as evidence of their delayed effects on micronucleus (MN) formation. The mean sizes of micronuclei induced after exposure to COL was significantly larger by a factor 2 as compared with that induced by X-irradiation, whereas those determined for the other four chemicals were almost equal to that induced by X-irradiation. These results demonstrate that the medaka gill-cell MN assay can detect chemically-induced chromosome damage, either directly or after metabolic activation, and spindle malfunction, and provide a basis for further development of the present assay system for testing cytogenetic activities of chemical agents.
- Published
- 2014
25. BACK MATTER
- Author
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Kazuo Fujikawa and Yoshimasa A Ono
- Published
- 2014
26. Parity-doublet representation of Majorana fermions and neutron oscillation
- Author
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Anca Tureanu, Kazuo Fujikawa, and Department of Physics
- Subjects
High Energy Physics - Theory ,Particle physics ,Neutron electric dipole moment ,FOS: Physical sciences ,01 natural sciences ,114 Physical sciences ,Superconductivity (cond-mat.supr-con) ,Condensed Matter - Strongly Correlated Electrons ,High Energy Physics - Phenomenology (hep-ph) ,0103 physical sciences ,Effective field theory ,010306 general physics ,Physics ,Condensed Matter::Quantum Gases ,Strongly Correlated Electrons (cond-mat.str-el) ,010308 nuclear & particles physics ,Condensed Matter - Superconductivity ,High Energy Physics::Phenomenology ,Parity (physics) ,Fermion ,Intrinsic parity ,Baryon ,MODEL ,High Energy Physics - Phenomenology ,MAJORANA ,Bogoliubov transformation ,NEUTRINOS ,High Energy Physics - Theory (hep-th) - Abstract
We present a parity-doublet theorem for the representation of the intrinsic parity of Majorana fermions, which is expected to be useful also in condensed matter physics, and it is illustrated to provide a criterion of neutron-antineutron oscillation in a BCS-like effective theory with $\Delta B=2$ baryon number violating terms. The CP violation in the present effective theory causes no direct CP violating effects in the oscillation itself, which is demonstrated by the exact solution, although it influences the neutron electric dipole moment in the leading order of small $\Delta B=2$ parameters. An analogue of Bogoliubov transformation, which preserves P and CP, is crucial in the analysis., Comment: 13 pages
- Published
- 2016
27. Electromagnetic interaction in theory with Lorentz invariant CPT violation
- Author
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Kazuo Fujikawa, Masud Chaichian, and Anca Tureanu
- Subjects
High Energy Physics - Theory ,Path (topology) ,Physics ,Ward–Takahashi identity ,Physics::General Physics ,Nuclear and High Energy Physics ,010308 nuclear & particles physics ,CPT symmetry ,High Energy Physics::Phenomenology ,FOS: Physical sciences ,Lorentz covariance ,01 natural sciences ,High Energy Physics - Phenomenology ,Phase factor ,Theoretical physics ,High Energy Physics - Phenomenology (hep-ph) ,Baryon asymmetry ,High Energy Physics - Theory (hep-th) ,Quantum electrodynamics ,0103 physical sciences ,Homogeneous space ,High Energy Physics::Experiment ,Gauge theory ,010306 general physics - Abstract
An attempt is made to incorporate the electromagnetic interaction in a Lorentz invariant but CPT violating non-local model with particle-antiparticle mass-splitting, which is regarded as a modified QED. The gauge invariance is maintained by the Schwinger non-integrable phase factor but the electromagnetic interaction breaks C, CP and CPT symmetries. Implications of the present CPT breaking scheme on the electromagnetic transitions and particle-antiparticle pair creation are discussed. The CPT violation such as the one suggested here may open a new path to the analysis of baryon asymmetry since some of the Sakharov constraints are expected to be modified., 12 pages, some remarks added; version to appear in Phys. Lett. B
- Published
- 2013
28. Naturalness in see-saw mechanism and Bogoliubov transformation
- Author
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Kazuo Fujikawa, Anca Tureanu, and Department of Physics
- Subjects
High Energy Physics - Theory ,Sterile neutrino ,Particle physics ,Nuclear and High Energy Physics ,Physics beyond the Standard Model ,FOS: Physical sciences ,114 Physical sciences ,01 natural sciences ,SYMMETRY-BREAKING ,Superconductivity (cond-mat.supr-con) ,Condensed Matter - Strongly Correlated Electrons ,High Energy Physics - Phenomenology (hep-ph) ,0103 physical sciences ,010306 general physics ,Neutrino oscillation ,Coupling constant ,Physics ,Strongly Correlated Electrons (cond-mat.str-el) ,010308 nuclear & particles physics ,Condensed Matter - Superconductivity ,High Energy Physics::Phenomenology ,BCS theory ,16. Peace & justice ,lcsh:QC1-999 ,FIELD-THEORY ,MAJORANA ,Bogoliubov transformation ,High Energy Physics - Phenomenology ,High Energy Physics - Theory (hep-th) ,High Energy Physics::Experiment ,Neutrino ,lcsh:Physics - Abstract
We present an alternative perspective on the see-saw mechanism for the neutrino mass, according to which the small neutrino mass is given as a difference of two large masses. This view emerges when an analogue of the Bogoliubov transformation is used to describe Majorana neutrinos in the Lagrangian of the see-saw mechanism, which is analogous to the BCS theory. The Bogoliubov transformation clarifies the natural appearance of Majorana fermions when C is strongly violated by the right-handed neutrino mass term with good CP in the single flavor model. Analyzing typical models with $m_{R}$= $10^{4}$ to $10^{15}$ GeV, it is shown that a hitherto unrecognized fine tuning of the order $m_{\nu}/m_{R}=10^{-15}$ to $10^{-26}$ is required to make the commonly perceived see-saw mechanism work in a natural setting, namely, when none of dimensionless coupling constants are very small., Comment: 14 pages; version published in Phys. Lett. B
- Published
- 2016
29. Lorentz invariant CPT breaking in the Dirac equation
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Kazuo Fujikawa and Anca Tureanu
- Subjects
Physics ,Nuclear and High Energy Physics ,Antiparticle ,Physics::General Physics ,010308 nuclear & particles physics ,FOS: Physical sciences ,Astronomy and Astrophysics ,Position and momentum space ,Lorentz covariance ,16. Peace & justice ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Symmetry (physics) ,Standard Model (mathematical formulation) ,symbols.namesake ,High Energy Physics - Phenomenology ,High Energy Physics - Phenomenology (hep-ph) ,Dirac equation ,0103 physical sciences ,symbols ,Coordinate space ,010306 general physics ,Mathematical physics ,Planck length - Abstract
If one modifies the Dirac equation in momentum space to $[\gamma^{\mu}p_{\mu}-m-\Delta m(\theta(p_{0})-\theta(-p_{0})) \theta(p_{\mu}^{2})]\psi(p)=0$, the symmetry of positive and negative energy eigenvalues is lifted by $m\pm \Delta m$ for a small $\Delta m$. The mass degeneracy of the particle and antiparticle is thus lifted in a Lorentz invariant manner since the combinations $\theta(\pm p_{0})\theta(p_{\mu}^{2})$ with step functions are manifestly Lorentz invariant. We explain an explicit construction of this CPT breaking term in coordinate space, which is Lorentz invariant but non-local at a distance scale of the Planck length. The application of this Lorentz invariant CPT breaking mechanism to the possible mass splitting of the neutrino and antineutrino in the Standard Model is briefly discussed., Comment: Talk given at the Memorial Meeting for Abdus Salam's 90th Birthday, Nanyang Technological University, Singapore, January 25-28, 2016 (to appear in the Proceedings)
- Published
- 2016
30. Nambu–Goldstone theorem and spin-statistics theorem
- Author
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Kazuo Fujikawa
- Published
- 2016
31. Dimensional regularization is generic
- Author
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Kazuo Fujikawa
- Subjects
Physics ,Quadratic growth ,High Energy Physics - Theory ,Nuclear and High Energy Physics ,010308 nuclear & particles physics ,FOS: Physical sciences ,Astronomy and Astrophysics ,Supersymmetry ,Renormalization group ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Standard Model ,Renormalization ,Dimensional regularization ,High Energy Physics - Phenomenology ,Quadratic equation ,High Energy Physics - Phenomenology (hep-ph) ,High Energy Physics - Theory (hep-th) ,Regularization (physics) ,0103 physical sciences ,010306 general physics ,Scalar field ,Mathematical physics - Abstract
The absence of the quadratic divergence in the Higgs sector of the Standard Model in the dimensional regularization is usually regarded to be an exceptional property of a specific regularization. To understand what is going on in the dimensional regularization, we illustrate how to reproduce the results of the dimensional regularization for the $\lambda\phi^{4}$ theory in the more conventional regularization such as the higher derivative regularization; the basic postulate involved is that the quadratically divergent induced mass, which is independent of the scale change of the physical mass, is kinematical and unphysical. This is consistent with the derivation of the Callan-Symanzik equation, which is a comparison of two theories with slightly different masses, for the $\lambda\phi^{4}$ theory without encountering the quadratic divergence. We thus suggest that the dimensional regularization is generic in a bottom-up approach starting with a successful low-energy theory. We also define a modified version of the mass independent renormalization for a scalar field which leads to the homogeneous renormalization group equation. Implications of the present analysis on the Standard Model at high energies and the presence or absence of SUSY at LHC energies are briefly discussed., Comment: 20 pages. To be published in the Proceedings of Conference on New Physics at the Large Hadron Collider, Nanyang Technological University, Singapore, 29 February to 4 March, 2016
- Published
- 2016
32. Yang–Mills Theory and Fermionic Path Integrals
- Author
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Kazuo Fujikawa
- Subjects
Bosonization ,Physics ,Nuclear and High Energy Physics ,010308 nuclear & particles physics ,High Energy Physics::Lattice ,General Physics and Astronomy ,Astronomy and Astrophysics ,Yang–Mills existence and mass gap ,Yang–Mills theory ,Faddeev–Popov ghost ,01 natural sciences ,High Energy Physics::Theory ,N = 4 supersymmetric Yang–Mills theory ,Grassmann number ,0103 physical sciences ,Path integral formulation ,Gauge theory ,010306 general physics ,Mathematical physics - Abstract
The Yang–Mills gauge field theory, which was proposed 60 years ago, is extremely successful in describing the basic interactions of fundamental particles. The Yang–Mills theory in the course of its developments also stimulated many important field theoretical machinery. In this brief review I discuss the path integral techniques, in particular, the fermionic path integrals which were developed together with the successful applications of quantized Yang–Mills field theory. I start with the Faddeev–Popov path integral formula with emphasis on the treatment of fermionic ghosts as an application of Grassmann numbers. I then discuss the ordinary fermionic path integrals and the general treatment of quantum anomalies. The contents of this review are mostly pedagogical except for a recent analysis of path integral bosonization.
- Published
- 2016
33. Conditional Measurement in Noncontextual Hidden-Variable Models
- Author
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Kazuo Fujikawa
- Subjects
Quantum Physics ,Physics and Astronomy (miscellaneous) ,Hidden variable theory ,FOS: Physical sciences ,Statistical physics ,Quantum Physics (quant-ph) ,Mathematics - Abstract
The noncontextual hidden variables models in $d=2$, such as the ones constructed by Bell and by Kochen and Specker, have difficulties in accounting for the conditional measurement of two non-orthogonal projectors. An idea of branching in the hidden variables space, which provides a means to realize the notion of reduction effectively and describe the state preparation, is suggested as a way to resolve the difficulties associated with the conditional measurement., 11 pages. Progress of Theoretical Physics (in press). arXiv admin note: text overlap with arXiv:1201.4421
- Published
- 2012
34. Neutrino–antineutrino mass splitting in the Standard Model and baryogenesis
- Author
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Kazuo Fujikawa, Anca Tureanu, and Department of Physics
- Subjects
High Energy Physics - Theory ,BARYON-NUMBER ,Particle physics ,Nuclear and High Energy Physics ,LEPTOGENESIS ,CPT symmetry ,UNIVERSE ,FOS: Physical sciences ,114 Physical sciences ,GAUGE THEORIES ,Baryon asymmetry ,High Energy Physics - Phenomenology (hep-ph) ,Effective field theory ,OSCILLATIONS ,Neutrino oscillation ,Physics ,High Energy Physics::Phenomenology ,WEINBERG-SALAM THEORY ,lcsh:QC1-999 ,Sphaleron ,INVARIANT CPT VIOLATION ,Baryogenesis ,High Energy Physics - Phenomenology ,High Energy Physics - Theory (hep-th) ,Leptogenesis ,High Energy Physics::Experiment ,PSEUDO-DIRAC NEUTRINOS ,SCALES ,Neutrino ,lcsh:Physics - Abstract
On the basis of a previously proposed mechanism of neutrino-antineutrino mass splitting in the Standard Model, which is Lorentz and $SU(2)\times U(1)$ invariant but non-local to evade $CPT$ theorem, we discuss the possible implications of neutrino-antineutrino mass splitting on neutrino physics and baryogenesis. It is shown that non-locality within a distance scale of the Planck length, that may not be fatal to unitarity in generic effective theory, can generate the neutrino-antineutrino mass splitting of the order of observed neutrino mass differences, which is tested in oscillation experiments, and non-negligible baryon asymmetry depending on the estimate of sphaleron dynamics. The one-loop order induced electron-positron mass splitting in the Standard Model is shown to be finite and estimated at $\sim 10^{-20}$ eV, well below the experimental bound $< 10^{-2}$ eV. The induced $CPT$ violation in the $K$-meson in the Standard Model is expected to be even smaller and well below the experimental bound $|m_{K}-m_{\bar{K}}, 17 pages, 1 figure
- Published
- 2015
35. Uncertainty Relation and Probability
- Author
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Koichiro Umetsu and Kazuo Fujikawa
- Subjects
High Energy Physics - Theory ,Physics ,Quantum Physics ,Physics and Astronomy (miscellaneous) ,Relation (database) ,Gravitational wave ,Quantum limit ,FOS: Physical sciences ,Sampling (statistics) ,General Relativity and Quantum Cosmology (gr-qc) ,Interpretations of quantum mechanics ,Evasion (ethics) ,General Relativity and Quantum Cosmology ,Standard deviation ,High Energy Physics - Theory (hep-th) ,Product (mathematics) ,Statistical physics ,Quantum Physics (quant-ph) - Abstract
The uncertainty relation and the probability interpretation of quantum mechanics are intrinsically connected, as is evidenced by the evaluation of standard deviations. It is thus natural to ask if one can associate a very small uncertainty product of suitably sampled events with a very small probability. We have shown elsewhere that some examples of the evasion of the uncertainty relation noted in the past are in fact understood in this way. We here numerically illustrate that a very small uncertainty product is realized if one performs a suitable sampling of measured data which occur with a very small probability. It is also shown that our analysis is consistent with the Landau-Pollak type uncertainty relation. It is suggested that the present analysis may help reconcile the contradicting views about the "standard quantum limit" in the detection of gravitational waves., 27 pages, 4 figures. To appear in Progress of Theoretical Physics (kyoto)
- Published
- 2011
36. Comment on the Uncertainty Relation with Periodic Boundary Conditions
- Author
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Kazuo Fujikawa
- Subjects
High Energy Physics - Theory ,Physics ,Quantum Physics ,Free particle ,Physics and Astronomy (miscellaneous) ,Relation (database) ,Mathematical analysis ,FOS: Physical sciences ,Boundary (topology) ,State (functional analysis) ,High Energy Physics - Theory (hep-th) ,Simple (abstract algebra) ,Periodic boundary conditions ,Limit (mathematics) ,Quantum Physics (quant-ph) ,Bloch wave - Abstract
The Kennard-type uncertainty relation $\Delta x\Delta p >\frac{\hbar}{2}$ is formulated for a free particle with given momentum < \hat{p}>$ inside a box with periodic boundary conditions in the large box limit. Our construction of a free particle state is analogous to that of the Bloch wave in a periodic potential. A simple Robertson-type relation, which minimizes the effect of the box boundary and may be useful in some practical applications, is also presented., Comment: 17 pages, to appear in Prog. Theor. Phys. (kyoto)
- Published
- 2010
37. Effects of fission neutrons on human thyroid tissues maintained in SCID mice
- Author
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Tetsuo Itoh, Rie Tsuboi-Kikuya, Taisei Nomura, Tadashi Hongyo, Yoriko Tokita, Fumio Matsuzuka, Keizo Hiramatsu, Shigeki Adachi, Hiroo Nakajima, Haruko Ryo, and Kazuo Fujikawa
- Subjects
Thyroid Hormones ,medicine.medical_specialty ,Ratón ,Health, Toxicology and Mutagenesis ,Transplantation, Heterologous ,Thyroid Gland ,Gene Expression ,Mice, SCID ,Radiation ,Biology ,Mice ,Internal medicine ,Gene expression ,Genetics ,medicine ,Relative biological effectiveness ,Animals ,Humans ,Neutrons ,Thyroid ,Dose-Response Relationship, Radiation ,Transplantation ,Endocrinology ,medicine.anatomical_structure ,Gamma Rays ,Apoptosis ,Immunology ,Relative Biological Effectiveness ,Nuclear Fission ,Hormone - Abstract
Morphology and function (secretion of thyroid hormone) of human thyroid tissues from Graves’ disease patients are well maintained in C57BL/6J- scid mice. Serum level of thyroid hormone was reduced by fission neutrons from the nuclear reactor UTR-KINKI, and changes in thyroid hormone by fission neutrons were bigger than those by low LET radiations, X-rays and 137 Cs γ-rays, suggesting high relative biological effectiveness (RBE; 6.5) of fission neutrons. Microarray analyses revealed that about 3% of genes showed more than 4-fold change in gene expression in the unexposed thyroid tissues against surgically resected thyroid tissues from the same patient, probably due to the difficult oxygen and nutrient supply shortly after transplantation. Dose-dependent changes in gene expression against unexposed concurrent controls were observed with increasing doses of fission neutrons (0.2–0.6 Gy) and 137 Cs γ-rays (1.0–3.0 Gy) and showed high RBE (4.2). Furthermore, there were some specific genes which showed more than 4-fold change in gene expression in all the thyroid tissues exposed to higher doses of radiation, especially neutrons (0.4 and 0.6 Gy), but none at lower doses (0.2 Gy of neutrons and 1.0 and 2.0 Gy of γ-rays). These genes related to degeneration, regeneration, apoptosis, and transcription, respond specifically and very sensitively to neutron injury in human thyroid tissues. This is the first experimental report that fission neutrons can induce some morphological and functional disorders in human tissues, showing high RBE against γ-ray exposure. These results are useful to evaluate the risks of fission neutrons and cosmic rays to humans.
- Published
- 2010
38. Locations of disulfide bonds and free cysteines in the heavy and light chains of recombinant human factor VIII (antihemophilic factor A)
- Author
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Ulla Hedner, Brad A. McMullen, Kazuo Fujikawa, Earl W. Davie, and Mirella Ezban
- Subjects
Protein Denaturation ,Stereochemistry ,Molecular Sequence Data ,Immunoglobulin light chain ,Biochemistry ,law.invention ,Iodoacetamide ,chemistry.chemical_compound ,law ,Humans ,Amino Acid Sequence ,Cysteine ,Disulfides ,Protein disulfide-isomerase ,Molecular Biology ,Peptide sequence ,Chromatography, High Pressure Liquid ,Factor VIII ,biology ,Chemistry ,Factor V ,Recombinant Proteins ,biology.protein ,Recombinant DNA ,Peptides ,Ceruloplasmin ,Sequence Analysis ,Research Article - Abstract
The locations of disulfide bonds and free cysteines in the heavy and light chains of recombinant human factor VIII were determined by sequence analysis of fragments produced by chemical and enzymatic digestions. The A1 and A2 domains of the heavy chain and the A3 domain of the light chain contain one free cysteine and two disulfide bonds, whereas the C1 and C2 domains of the light chain have one disulfide bond and no free cysteine. The positions of these disulfide bonds are conserved in factor V and ceruloplasmin except that the second disulfide bond in the A3 domain is missing in both factor V and ceruloplasmin. The positions of the three free cysteines of factor VIII are the same as three of the four cysteines present in ceruloplasmin. However, the positions of the free cysteines in factor VIII and ceruloplasmin are not conserved in factor V.
- Published
- 2008
39. Clear Evasion of the Uncertainty Relation with Very Small Probability
- Author
-
Kazuo Fujikawa and Koichiro Umetsu
- Subjects
High Energy Physics - Theory ,Physics ,Quantum Physics ,Physics and Astronomy (miscellaneous) ,Relation (database) ,Probabilistic logic ,Degrees of freedom (physics and chemistry) ,FOS: Physical sciences ,Quantum entanglement ,Evasion (ethics) ,Interpretation (model theory) ,Momentum ,High Energy Physics - Theory (hep-th) ,Phase space ,Statistical physics ,Quantum Physics (quant-ph) - Abstract
We entertain the idea that the uncertainty relation is not a principle, but rather it is a consequence of quantum mechanics. The uncertainty relation is then a probabilistic statement and can be clearly evaded in processes which occur with a very small probability in a tiny sector of the phase space. This clear evasion is typically realized when one utilizes indirect measurements, and some examples of the clear evasion appear in the system with entanglement though the entanglement by itself is not essential for the evasion. The standard Kennard's relation and its interpretation remain intact in our analysis. As an explicit example, we show that the clear evasion of the uncertainty relation for coordinate and momentum in the diffraction process discussed by Ballentine is realized in a tiny sector of the phase space with a very small probability. We also examine the uncertainty relation for a two-spin system with the EPR entanglement and show that no clear evasion takes place in this system with the finite discrete degrees of freedom., Comment: 21 pages and 1 figure. The title has been changed. The presentation of the entire manuscript has been modified and expanded. This revised version is to appear in the November issue of Progress of Theoretical Physics
- Published
- 2008
40. Comparative Susceptibility of Kidney and Gill Cells of Medaka Fish (Oryzias latipes) to Spontaneous and X-ray-induced Micronucleus Formation
- Author
-
Akinori Takai, Nao Kagawa, and Kazuo Fujikawa
- Subjects
Kidney ,Social Psychology ,biology ,Oryzias ,Cell ,Acridine orange ,Anatomy ,Environmental Science (miscellaneous) ,biology.organism_classification ,Kidney cell ,Andrology ,chemistry.chemical_compound ,medicine.anatomical_structure ,chemistry ,Micronucleus test ,Genetics ,medicine ,%22">Fish ,Micronucleus - Abstract
The frequency of micronucleated cells (MNCs) was measured in acridine orange (AO) stained kidney cells obtained from male and female medaka fish (Oryzias latipes) of known body weight before and after X-irradiation at a dose of 4 Gy. The MNC frequency in the kidney cells obtained from untreated and X-ray treated fish did not vary in correlation with the body weight in either gender, and neither did it show a significant gender-related difference. In both the untreated and treated groups, the number of MNCs in kidney cells per fish appeared to follow a Poisson distribution. These results are in agreement with those previously reported for the MNC frequency in gill cells of medaka fish. The average MNC frequency in kidney cells for the untreated fish was 0.4‰ (12/30000), which was significantly lower than 0.8‰ (24/30000) reported for gill cells. Similarly, a relatively lower frequency of X-ray-induced MNCs was evident for kidney cells (2.2‰; 69/30000) vs. gill cells (6.3‰; 191/30000). These results combined with previous reports support the use of AO to detect micronucleus formation in kidney cells, and further indicate that the kidney cell micronucleus assay can be used as a reliable and coincidently applied adjunct to the gill cell assay for medaka fish.
- Published
- 2008
41. Increased Levels of 8-Hydroxy-2′-Deoxyguanosine in Drosophila Larval DNA after Irradiation with 364-nm Laser Light but not with X-rays
- Author
-
Kazuaki Kawai, Hiroshi Kasai, Masakatsu Watanabe, Shoichi Higashi, Tomoe Negishi, Ritsuo Arakawa, Kazuo Fujikawa, and Takanori Nakamura
- Subjects
chemistry.chemical_classification ,Reactive oxygen species ,Programmed cell death ,8-Hydroxy-2'-deoxyguanosine ,General Medicine ,Biology ,medicine.disease_cause ,Biochemistry ,Molecular biology ,Ionizing radiation ,chemistry.chemical_compound ,chemistry ,In vivo ,Botany ,medicine ,Irradiation ,Physical and Theoretical Chemistry ,Thymidine ,Oxidative stress - Abstract
Exposure to UVA light causes damage to cellular components such as DNA and membrane lipids. We showed previously that UVA irradiation can induce mutations in Drosophila larvae and that the major lesions responsible for mutations were not thymidine dimers when wavelengths tested became longer. The use of a longer wavelength with UVA laser apparatus (364 nm) has made it possible to test the effects of this powerful light in biological organisms. In the present study, we irradiated third instar larvae of the urate-null Drosophila mutant strain y v ma-l, which is sensitive to oxidative stress, and compared the effects of 364 nm light irradiation with the effects of X-rays. To assay viability, some of the larvae were kept at 25 degrees C until they eclosed in order to obtain a measure of viability. The remaining larvae were used to measure the amount of 8-hydroxydeoxyguanosine (8-OHdG), an indicator of oxidative DNA damage. The amount of 8-OHdG increased and viability decreased in response to increased UV dose in both the y v ma-l and wild-type strains. With irradiation of 600 kJ m(-2), 8-OHdG/10(6)dG was 7.2 +/- 3.2 and 6.2 +/- 2.0 in y v ma-l and wild-type strains, respectively, whereas the respective levels were 2.2 +/- 0.6 and 2.3 +/- 0.8 without irradiation. Our results indicated that irradiation with a 364-nm laser light caused significant oxidative damage in Drosophila larval DNA; however, induction of the damage was not prohibited by urate. To the best of our knowledge, this is the first report of a study in whole animals that shows increased levels of 8-OHdG in response to 364-nm UVA. X-ray ionizing radiation is also thought to generate reactive oxygen species in irradiated cells. We found that the amount of 8-OHdG in DNA following X-ray radiation remained unchanged in both strains, though survival rates were affected. X-ray-generated oxidative damage in Drosophila cells was followed by cell death but not DNA base oxidation, and the damage was suppressed by urate. The overall results suggest significant differences in the major in vivo oxidative damage caused by 364-nm light and X-rays.
- Published
- 2007
42. Increased levels of 8-hydroxy-2′-deoxyguanosine in Drosophila larval DNA after irradiation with 364-nm laser light but not with X-rays
- Author
-
Tomoe, Negishi, Kazuaki, Kawai, Ritsuo, Arakawa, Shoichi, Higashi, Takanori, Nakamura, Masakatsu, Watanabe, Hiroshi, Kasai, and Kazuo, Fujikawa
- Subjects
Survival Rate ,8-Hydroxy-2'-Deoxyguanosine ,Ultraviolet Rays ,Larva ,Lasers ,X-Rays ,Animals ,Deoxyguanosine ,Drosophila ,DNA ,DNA Damage - Abstract
Exposure to UVA light causes damage to cellular components such as DNA and membrane lipids. We showed previously that UVA irradiation can induce mutations in Drosophila larvae and that the major lesions responsible for mutations were not thymidine dimers when wavelengths tested became longer. The use of a longer wavelength with UVA laser apparatus (364 nm) has made it possible to test the effects of this powerful light in biological organisms. In the present study, we irradiated third instar larvae of the urate-null Drosophila mutant strain y v ma-l, which is sensitive to oxidative stress, and compared the effects of 364 nm light irradiation with the effects of X-rays. To assay viability, some of the larvae were kept at 25 degrees C until they eclosed in order to obtain a measure of viability. The remaining larvae were used to measure the amount of 8-hydroxydeoxyguanosine (8-OHdG), an indicator of oxidative DNA damage. The amount of 8-OHdG increased and viability decreased in response to increased UV dose in both the y v ma-l and wild-type strains. With irradiation of 600 kJ m(-2), 8-OHdG/10(6)dG was 7.2 +/- 3.2 and 6.2 +/- 2.0 in y v ma-l and wild-type strains, respectively, whereas the respective levels were 2.2 +/- 0.6 and 2.3 +/- 0.8 without irradiation. Our results indicated that irradiation with a 364-nm laser light caused significant oxidative damage in Drosophila larval DNA; however, induction of the damage was not prohibited by urate. To the best of our knowledge, this is the first report of a study in whole animals that shows increased levels of 8-OHdG in response to 364-nm UVA. X-ray ionizing radiation is also thought to generate reactive oxygen species in irradiated cells. We found that the amount of 8-OHdG in DNA following X-ray radiation remained unchanged in both strains, though survival rates were affected. X-ray-generated oxidative damage in Drosophila cells was followed by cell death but not DNA base oxidation, and the damage was suppressed by urate. The overall results suggest significant differences in the major in vivo oxidative damage caused by 364-nm light and X-rays.
- Published
- 2007
43. Neutrino–Antineutrino Mass Splitting in the Standard Model: Neutrino Oscillation and Baryogenesis
- Author
-
Anca Tureanu and Kazuo Fujikawa
- Subjects
Physics ,Baryogenesis ,Particle physics ,Baryon asymmetry ,CPT symmetry ,High Energy Physics::Phenomenology ,Effective field theory ,High Energy Physics::Experiment ,Neutrino ,Neutrino oscillation ,Sphaleron ,Standard Model - Abstract
By adding a neutrino mass term to the Standard Model, which is Lorentz and SU(2) × U(1) invariant but nonlocal to evade CPT theorem, it is shown that nonlocality within a distance scale of the Planck length, that may not be fatal to unitarity in generic effective theory, can generate the neutrino–antineutrino mass splitting of the order of observed neutrino mass differences, which is tested in oscillation experiments, and non-negligible baryon asymmetry depending on the estimate of sphaleron dynamics. The one-loop order induced electron–positron mass splitting in the Standard Model is shown to be finite and estimated at ∼ 10-20 eV, well below the experimental bound < 10-2 eV. The induced CPT violation in the K-meson in the Standard Model is expected to be even smaller and well below the experimental bound |mK − mK| < 0.44 × 10−18GeV.
- Published
- 2015
44. Neutrino-antineutrino Mass Splitting in the Standard Model: Neutrino Oscillation and Baryogenesis
- Author
-
Anca Tureanu and Kazuo Fujikawa
- Subjects
Physics ,High Energy Physics - Theory ,Nuclear and High Energy Physics ,Particle physics ,Neutrino theory of light ,010308 nuclear & particles physics ,CPT symmetry ,High Energy Physics::Phenomenology ,FOS: Physical sciences ,General Physics and Astronomy ,Astronomy and Astrophysics ,Solar neutrino problem ,01 natural sciences ,Sphaleron ,Baryogenesis ,Nuclear physics ,High Energy Physics - Phenomenology ,High Energy Physics - Phenomenology (hep-ph) ,High Energy Physics - Theory (hep-th) ,0103 physical sciences ,Measurements of neutrino speed ,High Energy Physics::Experiment ,Neutrino ,010306 general physics ,Neutrino oscillation - Abstract
By adding a neutrino mass term to the Standard Model, which is Lorentz and $SU(2)\times U(1)$ invariant but non-local to evade $CPT$ theorem, it is shown that non-locality within a distance scale of the Planck length, that may not be fatal to unitarity in generic effective theory, can generate the neutrino-antineutrino mass splitting of the order of observed neutrino mass differences, which is tested in oscillation experiments, and non-negligible baryon asymmetry depending on the estimate of sphaleron dynamics. The one-loop order induced electron-positron mass splitting in the Standard Model is shown to be finite and estimated at $\sim 10^{-20}$ eV, well below the experimental bound $< 10^{-2}$ eV. The induced $CPT$ violation in the $K$-meson in the Standard Model is expected to be even smaller and well below the experimental bound $|m_{K}-m_{\bar{K}}, A brief review in MPLA, 10 pages
- Published
- 2015
45. S-Matrix Theory and Entanglement
- Author
-
Kazuo Fujikawa
- Subjects
Physics ,Photon entanglement ,Spin polarization ,Quantum mechanics ,Quantum Physics ,Quantum entanglement ,W state ,Squashed entanglement ,Spin (physics) ,Multipartite entanglement ,Entanglement witness - Abstract
But no good and simple criterion of entanglement for more complicated cases is known. This situation is rather strange since everybody talks about entanglement. How to produce and how to measure the entanglement are also interesting issues. When one measures the spin of the electron, for example, there are three major operators one can think of [1] a) Wigner spin, b) Dirac spin, c) Magnetic moment. The notion of chirality is important to distinguish these operators. Incidentally, many people talk about the Stern-Gerlach apparatus to measure the spin polarization of the electron. This is also strange since N. Bohr and N. F. Mott and other prominent people have shown many years ago that one cannot measure the electron spin polarization by a Stern-Gerlach apparatus, since the inhomogeneous magnetic field disturbs the motion of the electron so much and it is impossible to detect the spin orientation. The Stern-Gerlach particles are electrically neutral. One may ask if novel features appear in high energy physics? Chiral symmetry (including the use of weak interaction) can become important such as in a neutrino-antineutrino pair in Z decay
- Published
- 2015
46. Uncertainty principle, Shannon-Nyquist sampling and beyond
- Author
-
Kazuo Fujikawa, Mo-Lin Ge, Qing Zhao, and Yu-Long Liu
- Subjects
FOS: Computer and information sciences ,Signal processing ,Quantum Physics ,Uncertainty principle ,Information Theory (cs.IT) ,Computer Science - Information Theory ,Bandwidth (signal processing) ,FOS: Physical sciences ,General Physics and Astronomy ,Information theory ,symbols.namesake ,Compressed sensing ,Signal recovery ,Fourier analysis ,symbols ,Nyquist–Shannon sampling theorem ,Statistical physics ,Quantum Physics (quant-ph) - Abstract
Donoho and Stark have shown that a precise deterministic recovery of missing information contained in a time interval shorter than the time-frequency uncertainty limit is possible. We analyze this signal recovery mechanism from a physics point of view and show that the well-known Shannon-Nyquist sampling theorem, which is fundamental in signal processing, also uses essentially the same mechanism. The uncertainty relation in the context of information theory, which is based on Fourier analysis, provides a criterion to distinguish Shannon-Nyquist sampling from compressed sensing. A new signal recovery formula, which is analogous to Donoho-Stark formula, is given using the idea of Shannon-Nyquist sampling; in this formulation, the smearing of information below the uncertainty limit as well as the recovery of information with specified bandwidth take place. We also discuss the recovery of states from the domain below the uncertainty limit of coordinate and momentum in quantum mechanics and show that in principle the state recovery works by assuming ideal measurement procedures. The recovery of the lost information in the sub-uncertainty domain means that the loss of information in such a small domain is not fatal, which is in accord with our common understanding of the uncertainty principle, although its precise recovery is something we are not used to in quantum mechanics. The uncertainty principle provides a universal sampling criterion covering both the classical Shannon-Nyquist sampling theorem and the quantum mechanical measurement., 27 pages. Journal of Physical Society of Japan (in press)
- Published
- 2015
47. Hardy's paradox and measurement-disturbance relations
- Author
-
Choo Hiap Oh, Kazuo Fujikawa, and Sixia Yu
- Subjects
Thought experiment ,Physics ,Quantum Physics ,Uncertainty principle ,Hardy's paradox ,FOS: Physical sciences ,Quantum entanglement ,Atomic and Molecular Physics, and Optics ,Quantum nonlocality ,Quantum mechanics ,Weak measurement ,Quantum Physics (quant-ph) ,Relation (history of concept) ,Mathematical economics ,Eigenvalues and eigenvectors - Abstract
We establish a quantitative relation between Hardy's paradox and the breaking of uncertainty principle in the sense of measurement-disturbance relations in the conditional measurement of non-commuting operators. The analysis of the inconsistency of local realism with entanglement by Hardy is simplified if this breaking of measurement-disturbance relations is taken into account, and a much simplified experimental test of local realism is illustrated in the framework of Hardy's thought experiment. The essence of Hardy's model is identified as a combination of two conditional measurements, which give rise to definite eigenvalues to two non-commuting operators simultaneously in hidden-variables models. Better understanding of the intimate interplay of entanglement and measurement-disturbance is crucial in the current discussions of Hardy's paradox using the idea of weak measurement, which is based on a general analysis of measurement-disturbance relations., 6 pages. PRA (in press)
- Published
- 2015
48. Bosonization in the path integral formulation
- Author
-
Kazuo Fujikawa and Hiroshi Suzuki
- Subjects
Combinatorics ,Physics ,Bosonization ,High Energy Physics - Theory ,Nuclear and High Energy Physics ,Condensed Matter - Strongly Correlated Electrons ,High Energy Physics - Lattice ,High Energy Physics - Theory (hep-th) ,Strongly Correlated Electrons (cond-mat.str-el) ,High Energy Physics - Lattice (hep-lat) ,Path integral formulation ,FOS: Physical sciences ,Mathematical physics - Abstract
We establish the direct $d=2$ on-shell bosonization $\psi_{L}(x_{+})=e^{i\xi(x_{+})}$ and $\psi_{R}^{\dagger}(x_{-})=e^{i\xi(x_{-})}$ in path integral formulation by deriving the off-shell relations $\psi_{L}(x)\psi_{R}^{\dagger}(x)=\exp[i\xi(x)]$ and $\psi_{R}(x)\psi_{L}^{\dagger}(x)=\exp[-i\xi(x)]$. Similarly, the on-shell bosonization of the bosonic commuting spinor, $\phi_{L}(x_{+})=ie^{-i\xi(x_{+})}\partial^{+}e^{-i\chi(x_{+})}$, $\phi^{\dagger}_{R}(x_{-})=e^{-i\xi(x_{-})-i\chi(x_{-})}$ and $\phi_{R}(x_{-})=ie^{i\xi(x_{-})}\partial^{-}e^{+i\chi(x_{-})}$, $\phi^{\dagger}_{L}(x_{+})=e^{i\xi(x_{+})+i\chi(x_{+})}$, is established in path integral formulation by deriving the off-shell relations $\phi_{L}(x)\phi^{\dagger}_{R}(x)=ie^{-i\xi(x)}\partial^{+}e^{-i\chi(x)}$ and $\phi_{R}(x)\phi^{\dagger}_{L}(x)=ie^{i\xi(x)}\partial^{-}e^{i\chi(x)}$., Comment: 18 pages, the final version to appear in Phys. Rev. D
- Published
- 2015
49. Electronic structure and correlated wave functions of a few electron quantum dots
- Author
-
Kazuo Fujikawa, Hiroshi Ishida, and Tokuei Sako
- Subjects
Physics ,Normal mode ,Quantum dot ,Quantum mechanics ,Anharmonicity ,Electronic structure ,Configuration interaction ,Wave function ,Quantum number ,Molecular physics ,Full configuration interaction - Abstract
The energy spectra and wave functions of a few electrons confined by a quasi-one-dimensional harmonic and anharmonic potentials have been studied by using a full configuration interaction method employing a Cartesian anisotropic Gaussian basis set. The energy spectra are classified into three regimes of the strength of confinement, namely, large, medium and small. The polyad quantum number defined by a total number of nodes in the wave functions is shown to be a key ingredient to interpret the energy spectra for the whole range of the confinement strength. The nodal pattern of the wave functions exhibits normal modes for the harmonic confining potential, indicating collective motions of electrons. These normal modes are shown to undergo a transition to local modes for an anharmonic potential with large anharmonicity.
- Published
- 2015
50. Improved error-tradeoff and error-disturbance relations in terms of measurement error components
- Author
-
Xiao-Ming Lu, Kazuo Fujikawa, Sixia Yu, and Choo Hiap Oh
- Subjects
Physics ,Imagination ,Quantum circuit ,Operator (computer programming) ,Observational error ,Disturbance (geology) ,Uncertainty principle ,Control theory ,media_common.quotation_subject ,Quantum information ,Measure (mathematics) ,Atomic and Molecular Physics, and Optics ,media_common - Abstract
Heisenberg's uncertainty principle is quantified by error-disturbance tradeoff relations, which have been tested experimentally in various scenarios. Here we shall report various error-disturbance tradeoff relations by decomposing the measurement errors and disturbance into two different components, namely, operator bias and fuzziness. Our uncertainty relations reveal the tradeoffs between these two components of errors, and imply various conditionally valid error-tradeoff relations for the unbiased and projective measurements. We also design a quantum circuit to measure the two components of the error and disturbance.
- Published
- 2014
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