NAGASAWA Tomoaki

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Name
NAGASAWA Tomoaki
Affiliation
Tomakomai National College of Technology
Section
Department of Engineering of Innovation

Research Interests

 
 

Academic & Professional Experience

 
Apr 2006
 - 
Mar 2011
Lecturer, Anan National College of Technology General Arts
 

Published Papers

 
Yukihiro Fujimoto, Kohkichi Konno, Tomoaki Nagasawa, Rohta Takahashi
   Dec 2018
We consider the scattering problems of a quantum particle in a system with a single Y-junction and in ring systems with double Y-junctions. We provide new formalism for such quantum mechanical problems. Based on a path integral approach, we find c...
Kohkichi Konno, Tomoaki Nagasawa, Rohta Takahashi
Annals of Physics 385, 729 (2017)      Jun 2017
We discuss the scattering of a quantum particle by two independent successive point interactions in one dimension. The parameter space for two point interactions is given by Tex, which is described by eight real parameters. We perfor...
Kohkichi Konno, Tomoaki Nagasawa, Rohta Takahashi
Annals of Physics 375, 91 (2016)      May 2016
We consider the scattering of a quantum particle by two independent, successive parity-invariant point interactions in one dimension. The parameter space for the two point interactions is given by the direct product of two tori, which is described...
Yukihiro Fujimoto, K. Hasegawa, Tomoaki Nagasawa, Kenji Nishiwaki, Makoto Sakamoto, Kentaro Tatsumi
JHEP 1606 (2016) 178      Jan 2016
We propose a new mechanism to generate minuscule active neutrino masses in a five-dimensional~(5d) spacetime of an interval without introducing Tex singlet neutrinos. Under asymmetric boundary conditions on the two end points, a bulk mass fo...
Yukihiro Fujimoto, Tomoaki Nagasawa, Kenji Nishiwaki, Makoto Sakamoto
   Sep 2012
We propose a new model which can naturally explain origins of fermion generations, quark mass hierarchy, and Cabibbo-Kobayashi-Maskawa matrix simultaneously from geometry of an extra dimension. We take the extra dimension to be an interval with po...
Yukihiro Fujimoto, Tomoaki Nagasawa, Satoshi Ohya, Makoto Sakamoto
Prog. Theor. Phys. 126 (2011), 841-854      Aug 2011
We discuss gauge symmetry breaking in a general framework of gauge theories on an interval. We first derive a possible set of boundary conditions for a scalar field, which are compatible with several consistency requirements. It is shown that with...
Tomoaki Nagasawa, Satoshi Ohya, Kazuki Sakamoto, Makoto Sakamoto
SIGMA 7 (2011), 065      May 2011
We show that quantum mechanical supersymmetries are emerged in Kaluza-Klein spectrum of linearized gravity in several warped backgrounds as a consequence of higher-dimensional general coordinate invariance. These emergent supersymmetries play an e...
Tomoaki Nagasawa, Satoshi Ohya, Kazuki Sakamoto, Makoto Sakamoto, Kosuke Sekiya
J.Phys.A42:265203,2009      Dec 2008
We systematically formulate a hierarchy of isospectral Hamiltonians in one-dimensional supersymmetric quantum mechanics on an interval and on a circle, in which two successive Hamiltonians form N=2 supersymmetry. We find that boundary conditions c...
C. S. Lim, Tomoaki Nagasawa, Satoshi Ohya, Kazuki Sakamoto, Makoto Sakamoto
Phys.Rev.D77:065009,2008      Jan 2008
We study compactified pure gauge/gravitational theories with gauge-fixing terms and show that these theories possess quantum mechanical SUSY-like symmetries between unphysical degrees of freedom. These residual symmetries are global symmetries and...
C. S. Lim, Tomoaki Nagasawa, Satoshi Ohya, Kazuki Sakamoto, Makoto Sakamoto
Phys.Rev.D77:045020,2008      Oct 2007
We study a 5d gravity theory with a warped metric and show that two N = 2 supersymmetric quantum-mechanical systems are hidden in the 4d spectrum. The supersymmetry can be regarded as a remnant of higher-dimensional general coordinate invariance a...
Tomoaki Nagasawa, Makoto Sakamoto, Kazunori Takenaga
J.Phys. A38 (2005) 8053-8082      May 2005
We investigate Tex-extended supersymmetry in one-dimensional quantum mechanics on a circle with point singularities. For any integer Tex, Tex supercharges are explicitly constructed in terms of discrete transformations, and a class of singula...
C. S. Lim, Tomoaki Nagasawa, Makoto Sakamoto, Hidenori Sonoda
Phys.Rev. D72 (2005) 064006      Feb 2005
We show that a quantum-mechanical N=2 supersymmetry is hidden in 4d mass spectrum of any gauge invariant theories with extra dimensions. The N=2 supercharges are explicitly constructed in terms of differential forms. The analysis can be extended t...
Tomoaki Nagasawa, Makoto Sakamoto
   Oct 2004
We propose a higher dimensional scenario to solve the gauge hierarchy problem. In our formulation, a crucial observation is that a supersymmetric structure is hidden in the 4d spectrum of any gauge invariant theories with compact extra dimensions ...
Tomoaki Nagasawa, Makoto Sakamoto
Prog.Theor.Phys.112:629-638,2004      Jun 2004
We propose a mechanism of Higgsless gauge symmetry breaking with a large mass hierarchy. We consider a 5D gauge theory on an orbifold Tex. The gauge symmetry is broken by orbifolding and also nontrivial boundary conditions at fixed points. A...
Tomoaki Nagasawa, Makoto Sakamoto, Kazunori Takenaga
Phys.Lett. B583 (2004) 357-363      Nov 2003
We investigate N-extended supersymmetry in one-dimensional quantum mechanics on a circle with point singularities. For any integer n, N=2n supercharges are explicitly constructed and a class of point singularities compatible with supersymmetry is ...
Tomoaki Nagasawa, Makoto Sakamoto, Kazunori Takenaga
Phys.Lett.B562:358-364,2003      Dec 2002
We investigate supersymmetry in one-dimensional quantum mechanics with point interactions. We clarify a class of point interactions compatible with supersymmetry and present N=2 supersymmetric models on a circle with two point interactions as well...

Research Grants & Projects

 
quantum information
Basic Research Promotion Service for Health and Medical Field
hierarchy problem
Basic Research Promotion Service for Health and Medical Field
qunatum information
Basic Research Promotion Service for Health and Medical Field