Hadronic aspects of exotic baryons

In this talk I look into three different topics, addressing first the possibility that the $\Theta^+$ is a bound state of $K \pi N$, exploiting the results of this study to find out the contribution of two meson and one baryon components in the baryon antidecuplet and in the third place I present results on a new resonant exotic baryonic state which appears as dynamically generated by the Weinberg Tomozawa $\Delta K$ interaction.Comment: Talk at the International Workshop PENTAQUARK0

On the determination of Θ+\Theta^+ quantum numbers and other topics of exotic baryons

In this talk I look into three different topics, addressing first a method to determine the quantum numbers of the $\Theta^+$, then exploiting the possibility that the $\Theta^+$ is a bound state of $K \pi N$ and in the third place I present results on a new resonant exotic baryonic state which appears as dynamically generated by the Weinberg Tomozawa $\Delta K$ interaction.Comment: 9 pags. Talk in the NSTAR04 Workshop, Grenoble, march 200

Passive Sole Constraining Method to Stabilize 3D Passive Dynamic Walking

Inspired by the function of a toe and a lateral arch of a human foot, we propose a method to stabilize the biped walk by attaching unactuated toes and lateral arches. The toes and lateral arches work as adaptive braking of sagittal and lateral directions. They touch on the ground at the angle where the biped exceedingly inclines. After touching on the floor, the center of rotation changes at the landing positions. This change causes the reduction of the exceeding angular velocities toward sagittal and lateral directions. By setting appropriate heights of the toe and lateral arch during the swing phase, the walking robot is expected to be stabilized. To analyze the effects of the toe, we derived equations of motions and the state transition functions for a simplified 3D passive dynamic walker with toes. We clarified the potential stabilizing effect of the method from numerical simulations and preliminary experiments by a real-world biped with toes. Note that the proper setting of heights and the verification of the effect of lateral arches are on the way

Spin degeneracy in multi-hadron systems with a heavy quark

We study multi-hadron systems with a single heavy quark (charm or bottom) in the limit of heavy quark mass. The spin degeneracy of the states with quantum numbers $(j+1/2)^{P}$ and $(j-1/2)^{P}$ for $j \neq 0$, known in a normal hadron, can be generalized to multi-hadron systems. The spin degeneracy is the universal phenomena for any multi-hadron systems with a single heavy quark, irrespective of their internal structures, including compact multi-quarks, hadronic molecules and exotic nuclei. We demonstrate the spin degeneracy in the hadronic systems formed by a heavy hadron effective theory; $P^{(\ast)}N$ states with a $P^{(\ast)}=\bar{D}^{(\ast)}$, $B^{(\ast)}$ meson and a nucleon $N$, and a $P^{(\ast)}$ meson in nuclear matter.Comment: 9 pages, 1 figur