10 papers
Resonance Enhanced Tunneling
Sh. Matsumoto, M. Yoshimura
Time evolution of tunneling in thermal medium is examined using the real-time semiclassical formalism previously developed. Effect of anharmonic terms in the potential well is show…
Dynamics of barrier penetration in thermal medium: exact result for inverted harmonic oscillator
Sh. Matsumoto, M. Yoshimura
Time evolution of quantum tunneling is studied when the tunneling system is immersed in thermal medium. We analyze in detail the behavior of the system after integrating out the en…
New Kinetic Equation for Pair-annihilating Particles: Generalization of the Boltzmann Equation
Sh. Matsumoto, M. Yoshimura
A convenient form of kinetic equation is derived for pair annihilation of heavy stable particles relevant to the dark matter problem in cosmology. The kinetic equation thus derived…
Temperature Power Law of Equilibrium Heavy Particle Density
Sh. Matsumoto, M. Yoshimura
A standard calculation of the energy density of heavy stable particles that may pair-annihilate into light particles making up thermal medium is performed to second order of coupli…
Prolonged Decay and CP-asymmetry
I. Joichi, Sh. Matsumoto, M. Yoshimura
Time evolution of unstable particles that occur in the expanding universe is investigated. The off-shell effect not included in the Boltzmann-like equation is important for the dec…
Quantum Dissipation in Open Harmonic Systems: Operator Solution
I. Joichi, Sh. Matsumoto, M. Yoshimura
A finite number of harmonic oscillators coupled to infinitely many environment oscillators is fundamental to the problem of understanding quantum dissipation of a small system imme…