Supersymmetric extended string field theory in NS^n sector and NS^{n-1}-R sector

We construct a class of quadratic gauge invariant actions for extended string fields defined on the tensor product of open superstring state space for multiple open string Neveu-Schwarz (NS) sectors with or without one Ramond (R) sector. The basic idea is the same as for the bosonic extended string field theory developed by the authors [arXiv:1309.3850]. The theory for NS^n sector and NS^{n-1}-R sector contains general n-th rank tensor fields and (n-1)-th rank spinor-tensor fields in the massless spectrum respectively. In principle, consistent gauge invariant actions for any generic type of 10-dimensional massive or massless tensor or spinor-tensor fields can be extracted from the theory. We discuss some simple examples of bosonic and fermionic massless actions.Comment: 25 page

New Covariant Gauges in String Field Theory

A single-parameter family of covariant gauge fixing conditions in bosonic string field theory is proposed. It is a natural string field counterpart of the covariant gauge in the conventional gauge theory, which includes the Landau gauge as well as the Feynman (Siegel) gauge as special cases. The action in the Landau gauge is largely simplified in such a way that numerous component fields have no derivatives in their kinetic terms and appear in at most quadratic in the vertex.Comment: 24 page

Physical state representations and gauge fixing in string theory

We re-examine physical state representations in the covariant quantization of bosonic string. We especially consider one parameter family of gauge fixing conditions for the residual gauge symmetry due to null states (or BRST exact states), and obtain explicit representations of observable Hilbert space which include those of the DDF states. This analysis is aimed at giving a necessary ingredient for the complete gauge fixing procedures of covariant string field theory such as temporal or light-cone gauge.Comment: 16 page

An English Translation of Siblings Drowning by Takeo Arishima

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Proton-switchable vapochromic behaviour of a platinum(II)-carboxy-terpyridine complex

We synthesized a carboxy-substituted Pt(II)-terpyridine complex, i.e. [PtCl(Hctpy)] Cl ([1H] Cl; Hctpy = 4'-carboxy-2,2': 6',2''-terpyridine), that shows interesting switchable vapochromic behaviour upon protonation/deprotonation of the carboxy group. The as-synthesized dark-blue amorphous-like solid [1H] Cl center dot 3H(2)O was converted to a yellow crystalline solid, [1H] Cl center dot H2O, upon exposure to various polar organic solvent vapours (e.g., acetonitrile, ethanol, 1-propanol, and dichloromethane), which promote the removal of water molecules. The reaction of [1H] Cl center dot 3H(2)O with aqueous ammonia afforded a deprotonated bright-yellow crystalline complex, i.e. [PtCl(ctpy)]center dot H2O (1 center dot H2O), which exhibits red luminescence with an emission maximum at 622nm. Although the colour of 1 center dot H2O was not affected by exposure to various polar organic solvent vapours, interesting vapochromic luminescence with a remarkable red-shift of the emission maximum from 622 to 652 nm was observed upon exposure to saturated water vapour to form orange crystalline 1 center dot 3.5H(2)O X-ray structural analysis revealed that the planar and neutral complex molecule 1 forms a one-dimensional columnar structure with an intermolecular Pt center dot center dot center dot Pt distance of 3.518(2) angstrom in the orange crystall 1 center dot 3.5H(2)O, while the cationic molecule [1H](+) in the protonated form, [1H] Cl center dot H2O, generates a dimeric structure with an intermolecular Pt center dot center dot center dot Pt distance of 3.439(2) angstrom. This difference suggests that the vapochromic behaviours of the protonated and deprotonated forms could be caused by structural changes induced by water-vapour adsorption/desorption, which affect the intermolecular Pt. Pt distance, thereby changing the energy of the metal-metal-to-ligand charge-transfer (MMLCT) transition. These contrasting results for the protonated and deprotonated complexes clearly indicate that the hydrophilicity of complex 1 is significantly affected by protonation/deprotonation of the carboxy group. In addition, quasi-reversible conversion between [1H] Cl center dot 3H(2)O and 1 center dot H2O was achieved by exposure of the protonated and deprotonated forms to triethylamine and humid hydrochloric acid vapours, respectively

Level Truncated Tachyon Potential in Various Gauges

New gauge fixing condition with single gauge parameter proposed by the authors is applied to the level truncated analysis of tachyon condensation in cubic open string field theory. It is found that the only one real non-trivial extremum persists to appear in the well-defined region of the gauge parameter, while the other solutions are turned out to be gauge-artifacts. Contrary to the previously known pathology in the Feynman-Siegel gauge, tachyon potential is remarkably smooth enough around Landau-type gauge.Comment: 13 pages, 5 figures. For associated movie files, see http://hep1.c.u-tokyo.ac.jp/~kato/sft