Properties of hadron and quark matter studied with a molecular dynamics

We study the hadron-quark phase transition in a molecular dynamics (MD) of quark degrees of freedom. The hadron state at low density and temperature, and the deconfined quark state at high density and temperature are observed in our model. We investigate the equations of state and draw the phase-diagram at wide baryon density and temperature range. We also discuss the transport property, e.g. viscosity, of $q\bar{q}$ matter. It is found that the ratio of the shear viscosity to the entropy density is less than one for quark matter.Comment: Poster presentation at Quark Matter 200

General pairing interactions and pair truncation approximations for fermions in a single-j shell

We investigate Hamiltonians with attractive interactions between pairs of fermions coupled to angular momentum J. We show that pairs with spin J are reasonable building blocks for the low-lying states. For systems with only a J = Jmax pairing interaction, eigenvalues are found to be approximately integers for a large array of states, in particular for those with total angular momenta I le 2j. For I=0 eigenstates of four fermions in a single-j shell we show that there is only one non-zero eigenvalue. We address these observations using the nucleon pair approximation of the shell model and relate our results with a number of currently interesting problems.Comment: a latex text file and 2 figures, to be publishe

Oxygen reduction behavior of rutile-type iridium oxide in sulfuric acid solution

ArticleELECTROCHIMICA ACTA. 54(2):566-573 (2008)journal articl

Ground state spin 0+^+ dominance of many-body systems with random interactions and related topics

In this talk we shall show our recent results in understanding the spin$^{\rm parity}$ 0$^+$ ground state (0 g.s.) dominance of many-body systems. We propose a simple approach to predict the spin $I$ g.s. probabilities which does not require the diagonalization of a Hamiltonian with random interactions. Some findings related to the 0 g.s. dominance will also be discussed.Comment: 11 pages and 4 figure