Heterotic string field theory with cyclic L-infinity structure

We construct a complete heterotic string field theory that includes both the Neveu-Schwarz and Ramond sectors. We give a construction of general string products, which realizes a cyclic L-infinity structure and thus provides with a gauge-invariant action in the homotopy algebraic formulation. Through a map of the string fields, we also give the Wess-Zumino-Witten-like action in the large Hilbert space, and verify its gauge invariance independently.Comment: 31 pages, 1figure, section for four point amplitudes is inserted; v3 English has been improved; v4 English is improved, Eq(5.16b) is corrected (published as erratum), Eq (A.19) is adde

Relativisitic mean field theory of surface pion condensation in finite nuclei

We study the possible occurrence of surface pion condensation in finite nuclei in the relativistic mean field (RMF) theory. We are led to this conjecture due to the essential role of pions in few-body systems and the recent (p,n) experiments performed at RCNP for spin-isospin excitations of medium and heavy nuclei. We calculate explicitly various N=Z closed shell nuclei with finite pion mean field in the RMF framework and demonstrate the actual occurrence of surface pion condensation.Comment: 4 pages, 1 figur

Tensor correlation in 4He with the tensor-optimized shell model

We study the characteristics of the tensor correlation in $^4$He using a shell model type method. We treat the tensor force explicitly by performing a configuration-mixing calculation in the $2p2h$ basis and include single-particle states up to intermediately high angular momenta. We adopt the Gaussian expansion method for the quantitative description of the spatial shrinkage of the single-particle states to optimize the tensor correlation. We are able to describe the full strength of the tensor correlation for $^4$He in the shell model type method by realizing convergence. We call this model the tensor-optimized shell model. It is found that in $^4$He, three specific $2p2h$ configurations are strongly coupled with the $(0s)^4$ configuration due to the characteristic features of the tensor operator.Comment: 18 pages, 8 figures, Changed content, To be Published in Prog. Theor. Phys. 117(2007

Study of the effect of the tensor correlation in oxygen isotopes with the charge- and parity-projected Hartree-Fock method

Recently, we developed a mean-field-type framework which treats the correlation induced by the tensor force. To exploit the tensor correlation we introduce single-particle states with the parity and charge mixing. To make a total wave function have a definite charge number and a good parity, the charge number and parity projections are performed. Taking a variation of the projected wave function with respect to single-particle states a Hartree-Fock-like equation, the charge- and parity-projected Hartree-Fock equation, is obtained. In the charge- and parity-projected Hartree-Fock method, we solve the equation selfconsistently. In this paper we extend the charge- and parity-projected Hartree-Fock method to include a three-body force, which is important to reproduce the saturation property of nuclei in mean-field frameworks. We apply the charge- and parity-projected Hartree-Fock method to sub-closed-shell oxygen isotopes (14O, 16O, 22O, 24O, and 28O) to study the effect of the tenor correlation and its dependence on neutron numbers. We obtain reasonable binding energies and matter radii for these nuclei. It is found that relatively large energy gains come from the tensor force in these isotopes and there is the blocking effect by occupied neutron orbits on the tensor correlation

H_2 Dissociative Adsorption at the Armchair Edges of Graphite

We investigate and discuss how hydrogen behaves at the edges of a graphite sheet, in particular the armchair edge. Our density functional theory-based calculations results show that, in contrast to the zigzag edge [cf., e-J. Surf. Sci. Nanotech. 2 (2004) 77], regardless of orientation, there is an activation barrier hindering H_2 dissociation at the armchair edges. And once they do get dissociatively adsorbed at the armchair edges, we find that it would be extremely hard to desorb the H from their adsorption sites at the armchair edges. Furthermore, we also found that, consistent with our earlier conclusions [cf., J. Phys. Soc. Jpn. 72 (2003) 1867], it is unlikely that we would find a whole H_2 in between plain graphite sheets.Comment: 4 pages, 5 figures, preprin

L’art japonais et moi

Plus de la moitié de ma vie d’artiste contemporain s’est déroulée à l’étranger. On a beau parler aujourd’hui de monde globalisé, le travail d’un artiste est toujours considéré comme émanant d’une manière ou d’une autre de sa culture d’origine. Dans mon pays, je n’ai pas conscience d’être japonais, parce qu’il n’y a aucune nécessité à cela. Mais à l’étranger, je deviens un homme venu de cette lointaine contrée. À la fin de la période glaciaire, il y a environ 100 000 ans, le niveau des océans ..