arXiv subjects

H. Kuwabara

Publications and source records attributed to H. Kuwabara.

3 recordsLinked to original sources

arXiv2015

Time dependent Pais-Uhlenbeck oscillator and its decomposition

The Pais-Uhlenbeck(PU) oscillator is the simplest model with higher time derivatives. Its properties were studied for a long time. In this paper, we extend the 4th order free PU oscillator to a more non-trivial case, dubbed the 4th order time dependent PU oscillator, which has time dependent frequencies. We show that this model cannot be decomposed into two harmonic oscillators in contrast to the original PU oscillator. An interaction is added by the coordinate transformation of Smilga.

gr-qc↗

arXiv1996

Light Vector Mesons in Nuclear Matter

We summarize the current theoretical and experimental status of the spectral changes of vector mesons ($ρ$, $ω$, $ϕ$) in nuclear medium. Various approaches including QCD sum rules, effective theory of hadrons and bag models show decreasing of the vector meson masses in nuclear matter. Possibility to detect the mass shift through lepton pairs in $γ-A$, $p-A$ and $A-A$ reactions are also discussed.

nucl-th↗

arXiv1995

phi-meson in Nuclear Matter

$ϕ$-meson mass in nuclear matter ($m_ϕ^*$) is investigated using an effective Lagrangian of $ϕ$ interacting with octet baryons. $m_ϕ^*$ decreases by a few \% in nuclear matter due to the current conservation and effective nucleon/hyperon masses. Its implication to the p-A and A-A collisions are briefly discussed.

nucl-th↗