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Article type: Cover
2001 Volume 104 Issue 2 Pages
Cover1-
Published: November 20, 2001
Released on J-STAGE: October 02, 2017
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Article type: Appendix
2001 Volume 104 Issue 2 Pages
App1-
Published: November 20, 2001
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Article type: Appendix
2001 Volume 104 Issue 2 Pages
B1-B3
Published: November 20, 2001
Released on J-STAGE: October 02, 2017
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[in Japanese], [in Japanese]
Article type: Article
2001 Volume 104 Issue 2 Pages
B4-B8
Published: November 20, 2001
Released on J-STAGE: October 02, 2017
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Noboru Takigawa, Sachie Kimura, David Brink
Article type: Article
2001 Volume 104 Issue 2 Pages
B9-B15
Published: November 20, 2001
Released on J-STAGE: October 02, 2017
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Heavy-ion fusion reactions at energies below the Coulomb barrier are typical examples of the quantum tunneling under influence of the intrinsic degrees of freedom. In order to calculate the barrier transmission probability it is necessary to have a framework which describes the classically allowed and the tunneling regions in a unified way. Another example which requires such a theory is the low energy nuclear reactions in laboratory experiments, where the bound electrons in the target nucleus yield screening effects on the potential barrier between the target and projectile nuclei. To this end, we develop a novel semiclassical theory of quantum tunneling under influence of other degrees of free-dom. The method relies upon the mean field variational principle to handle the coupling between the tunneling and the other degrees of freedom, and consistently describes the classically allowed and the tunneling regions. Also, the method can be applied to a wide range of problems with various degree of adiabaticity.
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Sachie Kimura, Noboru Takigawa
Article type: Article
2001 Volume 104 Issue 2 Pages
B16-B20
Published: November 20, 2001
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Heavy-ion fusion reactions at energies below the Coulomb barrier are typical examples of the quantum tunneling, where intrinsic degrees of freedom strongly influence the barrier transmission probability of a macroscopic motion. A related example is the low energy nuclear reaction in laboratories, where the bound electrons in the target nucleus modify the reaction rate through the screening effect on the fusion barrier. Here we discuss the characteristics of the effects of intrinsic degrees of freedom on the barrier transmission probability when they are initially in an excited state using a two-level coupled-channels calculations. In the case of fast tunneling, where the intrinsic motion is slow, the barrier transmission probability is affected in the same manner irrespective of whether the initial intrinsic state is the ground or an excited state. On the other hand, a fast intrinsic motion hinders the barrier transmission for whole energy region if the initial state is an excited state contrary to the enhancement in the case when the intrinsic motion starts from the ground state. We show also that a significant transition from the excited state to the ground state takes place in low energy region even for the cases, where one would expect almost no non-adiabatic transitions because of the large excitation energy of the intrinsic motion.
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Sh. Matsumoto
Article type: Article
2001 Volume 104 Issue 2 Pages
B21-B26
Published: November 20, 2001
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Time evolution of tunneling in thermal medium is studied using a standard model of environment interaction. A semiclassical formula for the particle motion in a metastable state of one dimensional system is combined with the quantum tunneling rate through a potential barrier, to derive the tunneling rate in medium. Effect of dissipation is clarified in a real-time formalism. If the friction η from environment is small enough, the nonlinear resonance effect due to the anharmonic terms in the potential well is shown to enhance the tunneling rate at finite times of order 1/η.
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[in Japanese], Aldo Bonasera, [in Japanese]
Article type: Article
2001 Volume 104 Issue 2 Pages
B27-B31
Published: November 20, 2001
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Kiyoshi Kato
Article type: Article
2001 Volume 104 Issue 2 Pages
B32-B37
Published: November 20, 2001
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The extended completenss relation including bound, resonant and contunuum states is discussed in the framework of the complex scaling method. Applying the extended completeness relation to calculation of Green's function, breakup reactions of two- and three-body systems are studied. Based on the successful results of the complex scaling method in description of bound and unbound states, we discuss the level density in this framwork.
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Shigeyoshi AOYAMA
Article type: Article
2001 Volume 104 Issue 2 Pages
B38-
Published: November 20, 2001
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[in Japanese], [in Japanese], [in Japanese], [in Japanese]
Article type: Article
2001 Volume 104 Issue 2 Pages
B39-B43
Published: November 20, 2001
Released on J-STAGE: October 02, 2017
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[in Japanese]
Article type: Article
2001 Volume 104 Issue 2 Pages
B44-B45
Published: November 20, 2001
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[in Japanese]
Article type: Article
2001 Volume 104 Issue 2 Pages
B46-B47
Published: November 20, 2001
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[in Japanese]
Article type: Article
2001 Volume 104 Issue 2 Pages
B48-B50
Published: November 20, 2001
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[in Japanese]
Article type: Article
2001 Volume 104 Issue 2 Pages
B51-B56
Published: November 20, 2001
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[in Japanese]
Article type: Article
2001 Volume 104 Issue 2 Pages
B57-B58
Published: November 20, 2001
Released on J-STAGE: October 02, 2017
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M. Ueda, A.J. Sargeant, M.S. Hussein, M.P. Pato, N. Takigawa
Article type: Article
2001 Volume 104 Issue 2 Pages
B59-B64
Published: November 20, 2001
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We formulate the attenuation of the intensities of two-step E2 7-transitions within a superdeformed band which results from mixing with normally deformed states based on a nuclear reaction theory. It is found that a chaotic nature of the normally deformed states has a significant influence on the attenuation of the intensities of El 7-transitions within a superdeformed band when there exist not so many doorway states which couple to superde-formed states. We also discuss whether the sharp increase of the attenuation at a certain member of the band is caused by the chaotic nature of the normally deformed states or more due to the strong spin dependence of the tunneling barrier separating the superdeformed and normally deformed states.
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[in Japanese], [in Japanese], [in Japanese], [in Japanese]
Article type: Article
2001 Volume 104 Issue 2 Pages
B65-B68
Published: November 20, 2001
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[in Japanese]
Article type: Article
2001 Volume 104 Issue 2 Pages
B69-B74
Published: November 20, 2001
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[in Japanese], [in Japanese], [in Japanese]
Article type: Article
2001 Volume 104 Issue 2 Pages
B75-B77
Published: November 20, 2001
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[in Japanese], [in Japanese]
Article type: Article
2001 Volume 104 Issue 2 Pages
B78-B82
Published: November 20, 2001
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Kazuki Ohmori
Article type: Article
2001 Volume 104 Issue 2 Pages
1-67
Published: November 20, 2001
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We review the recent studies of tachyon condensation in string field theory. After introducing the open string field theory both for bosonic string and for superstring, we use them to examine the conjecture that the unstable configurations of the D-branes will decay into the 'closed string vacuum' through the tachyon condensation. And we describe the attemps to construct a lower-dimensional bosonic D-brane as an unstable lump solution of the string field equation. This paper is based on my master's thesis submitted to Department of Physics, Faculty of Science, University of Tokyo on January 2001.
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Article type: Appendix
2001 Volume 104 Issue 2 Pages
App2-
Published: November 20, 2001
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Article type: Appendix
2001 Volume 104 Issue 2 Pages
App3-
Published: November 20, 2001
Released on J-STAGE: October 02, 2017
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Article type: Cover
2001 Volume 104 Issue 2 Pages
Cover2-
Published: November 20, 2001
Released on J-STAGE: October 02, 2017
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Article type: Cover
2001 Volume 104 Issue 2 Pages
Cover3-
Published: November 20, 2001
Released on J-STAGE: October 02, 2017
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