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Search Results: 1 - 10 of 118019 matches for " T. Mizutani "
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Effective Lagrangian Study of $γp \to K^+ Λ$ (spin 3/2 resonances and their off-shell effects)
T. Mizutani
Physics , 1998,
Abstract: The purpose of the present discussion is to supplement the talk, by B.~Saghai at this workshop, on the study of the electromagnetic production of strangeness on the nucleon based upon effective Lagrangian methods. Here we focus on the proper treatment of the spin 3/2 resonances and their associated effects due to the spin 1/2 component of the corresponding fields when they are {\it off the mass shell}.
D Mesons in Nuclear Matter: A DN Coupled-Channel Equations Approach
T. Mizutani,A. Ramos
Physics , 2006, DOI: 10.1103/PhysRevC.74.065201
Abstract: A set of coupled two-body scattering equations is solved for the DN system embedded in an iso-symmetric nuclear matter. The in-medium behavior of charmed D mesons: (D^+,D^0), is investigated from the self-consistent solution within this scheme. The effective meson-baryon Lagrangian in charm quantum number one sector, the key ingredient in the present study, is adopted from a recent model by Hofmann and Lutz which has aimed at combining the charmed meson degree of freedom in a consistent manner with chiral unitary models. After a critical examination, the original model is modified in several important aspects, such as the method of regularization, in order to be more consistent and practical for our objective. The resultant interaction is used to reproduce the position and width of the s-wave \Lambda_c(2593) resonance in the isospin zero DN channel. In the isospin one channel, it generates a rather wide resonance at \~2770 MeV. The corresponding in-medium solution is then sought by incorporating Pauli blocking and the D- and \pi-meson dressing self-consistently. At normal nuclear matter density, the resultant \Lambda_c (2593) is found to stay narrow and shifted at a lower energy, while the I=1 resonance is lowered in position as well and broadened considerably. The possible implication of our findings on the J/\Psi suppression, etc. in relativistic heavy ion collisions is briefly discussed.
Self-energy of Heavy Quark
M. A. Ivanov,T. Mizutani
Physics , 1995, DOI: 10.1007/BF01565263
Abstract: We demonstrate that to calculate the self-energy of a heavy quark in the heavy quark limit (or the heavy fermion limit in what is called the Baryon Chiral Perturbation Theory), the use of standard dimensional regularization provides only the quantum limit: opposite to the heavy quark (or classical) limit that one wishes to obtain. We thus devised a standard ultraviolet/infrared regularization procedure in calculating the one- and two-loop contributions to the heavy quark self-energy in this limit. Then the one-loop result is shown to provide the standard classical Coulomb self-energy of a static colour source that is linearly proportional to the untraviolet cutoff $\Lambda$. All the two-loop contributions are found to be proportional to $\Lambda \ln(\Lambda/\lambda)$ where $\lambda$ is the infrared cutoff. Often only the contribution from the bubble (light quarks, gluon and ghost) insertion to the gluon propagator has been considered as the $O(\alpha_s)$ correction to the Coulomb energy to this order. Our result shows that other contributions are of the same magnitude, thus have to be taken into account.
Heavy quark limit in the model with confined light quarks and infrared heavy quark propagators
M. A. Ivanov,T. Mizutani
Physics , 1994, DOI: 10.1063/1.48164
Abstract: We have studied the weak decay constants and the Isgur-Wise form factor of the B and D mesons in the heavy quark limit, by employing a relativistic quark confinement model. It is an attempt to improve our previous work within the same line of thinking, but by incorporating a couple of novel aspects. First, the infrared behavior of the heavy quark is considered by modifying its conventional propagator in terms of a single parameter $\nu$. Second, the mass difference of the heavy meson and heavy quark: $E=m_H-M_Q$ has been included. It is found that the weak decay constants depend strongly on the mass difference E with a relatively mild $\nu$ dependence. As for the Isgur-Wise function it is controlled more sensitively by the infrared parameter $\nu$, leading to its suppression at maximum meson recoil.
Reaction γπ\to ππin a confined quark model
M. A. Ivanov,T. Mizutani
Physics , 1995, DOI: 10.1103/PhysRevD.53.1470
Abstract: A confined quark model study in a couple of chirally anomalous processes is presented in comparison with effective meson Lagrangian approaches of various kind. The processes considered are \pi^0 \to \gamma \gamma and \gamma \to \pi^+ \pi^- \pi^0 (or the equivalent \pi \gamma \to \pi\pi) for which there is a well-known low energy theorem relating the latter amplitude with the former one by a very simple algebraic relation in the zero energy (or chiral, or soft pion) limit. Our quark model naturally generates the so-called contact term in the amplitude for the second process, but with the opposite sign to what effective chiral meson models indicate. A reinterpretation of our vector pole contribution restores the consistency, however. While the first reaction is observed to serve in it calibrating various models, it is found difficult, based upon the quality of the existing data in the second reaction, to single out the best model, which appears indispensable for testing the validity of the above low energy theorem. Thus the proposed experiments and their analyses should aim at attaining an optimal accuracy.
The box anomaly and radiative decays of η(η')-mesons
M. A. Ivanov,T. Mizutani
Physics , 1997,
Abstract: We report on a confined quark model calculation of the transition form factors for the radiative decays of \eta(\eta')->\gamma l^+l^- and \eta(\eta')->\gamma\pi^+\pi^-. The \eta-\eta' mixing angle \theta_P is determined from the set of data on the electromagnetic \eta(\eta') decays. It is found that \theta_P\sim -16.5. The analysis of the dipionic mass distribution in the decay \eta'->\gamma\pi^+\pi^- confirms the existence of a non-resonant contribution which is the box anomaly.
Issues Related to Accounting Education for NFPs in the U.S.  [PDF]
Fuminobu Mizutani
Open Journal of Accounting (OJAcct) , 2016, DOI: 10.4236/ojacct.2016.51001
Abstract: There have been no efforts to organize existing works about accounting education for NFPs. This paper is an article reviewing existing works published in the 21st century. There is a sufficient volume of cases to use the case method. Some of the existing works were about active learning (mainly service learning). Some existing works can be used to improve lectures. Some existing works can help faculty members to design their curriculums. However, some issues still remain and these issues should be resolved in the future. As a whole, the problem of existing works is lack of sufficient concerns about other academic areas. Some of future works are hoped to be more interdisciplinary.
IL-1 Receptor Type II Production Is Upregulated by IL-4 and IL-13, and Downregulated by IFN-γ in Mouse Gingival Epithelial Cells  [PDF]
Y. Kamiya, Y. Ishihara, H. Kamei, Y. Ozawa, H. Mizutani, K. Kubo, H. Maeda, T. Noguchi
Modern Research in Inflammation (MRI) , 2014, DOI: 10.4236/mri.2014.32005
Abstract:

Background and Objective: Interleukin-1 (IL-1) binds to 2 distinct and separate receptors, types I and II (IL-1RI and IL-1RII, respectively). The binding of IL-1 to IL-1RI induces cellular signaling and biological effects, whereas binding to IL-1RII does not induce cellular signaling and indirectly inhibits IL-1 biological activities such as that of the decoy receptor. Recently, Suzukiet al.reported that soluble IL-1RII (sIL-1RII) was detected in gingival crevicular fluid from a periodontitis patient. However, it remains unclear which cells produce sIL-1RII detected in periodontal tissues. We examined the localization of IL-1RII producing cells in gingival tissues as well as related production control mechanisms. Material and Methods: IL-1RII mRNA expression in gingival epithelial cells (GE1) was performed by real-time PCR analysis, while the amount of sIL-1RII production in supernatant from GE1 cells was examined by dot-blot analysis. Involvement of the phosphorylation of STAT6 in the signaling pathway was determined by western blot analysis. Statistical analysis was performed with Student’st-test. Results: Culturing with IL-4 and IL-13 significantly increased IL-1RII mRNA to levels 10.5-and 8.89-fold, respectively, above that of the control (p< 0.01), while addition of interferon-γ (IFN-γ) significantly suppressed IL-1RII mRNA by 0.22-fold as compared to the control (p< 0.05). Soluble IL-1RII in the supernatant of cultured GE1 cells was increased by IL-4 and IL-13, and decreased by IFN-γ, while western blotting determines the suppression of IL-1RII production by IFN-γ. Without the addition of IL-4 or IL-13 with or without

Heavy-to-light form factors in the quark model with heavy propagators
M. A. Ivanov,T. Mizutani,Yu. M. Valit
Physics , 1996, DOI: 10.1007/s006010050086
Abstract: We calculate the heavy-to-light form factors in the relativistic quark model with heavy infrapropagators. Their q^2-dependence in the physical region is defined by two parameters: the "infrared" parameter \nu characterizing the infrared behavior of the heavy quark and the mass difference of the heavy meson and heavy quark E=m_H-M_Q. It is found that the values of the D\to K(K^*) and D\to \pi(\rho) form factors at q^2=0 are in excellent agreement with the available experimental data and other approaches whereas these values for B\to \pi(\rho) transitions are found to be larger than those of several other models. The obtained form factors are used to calculate the widths of the semileptonic decays of B and D mesons. The comparison of our results with the available experimental data and other approaches is given
Three-Body approach to the K^- d Scattering Length in Particle Basis
A. Bahaoui,C. Fayard,T. Mizutani,B. Saghai
Physics , 2002, DOI: 10.1103/PhysRevC.66.057001
Abstract: We report on the first calculation of the scattering length A_{K^-d} based on a relativistic three-body approach where the two-body input amplitudes coupled to the Kbar N channels have been obtained with the chiral SU(3) constraint, but with isospin symmetry breaking effects taken into account. Results are compared with a recent calculation applying a similar set of two-body amplitudes,based on the fixed center approximation, considered as a good approximation for a loosely bound target, and for which we find significant deviations from the exact three-body results. Effects of the hyperon-nucleon interaction, and deuteron $D$-wave component are also evaluated.
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