Re-integerization of fractional charges in the correlated quarter-filled band

Previous work has demonstrated the existence of soliton defect states with charges +/-e/2 in the limits of zero and infinite on-site Coulomb interactions in the one-dimensional (1D) quarter-filled band. For large but finite on-site Coulomb interaction, the low temperature 2kF bond distortion that occurs within the 4kF bond-distorted phase is accompanied by charge ordering on the sites. We show that a "re-integerization" of the defect charge occurs in this bond-charge-density-wave state due to a "binding" of the fractional charges. We indicate briefly possible implications of this result for mechanisms of organic superconductivity.     

Absence of superconductivity in the half-filled band Hubbard model on the anisotropic triangular lattice

We report exact calculations of magnetic and superconducting pair-pair correlations for the half-filled band Hubbard model on an anisotropic triangular lattice. Our results for the magnetic phases are similar to those obtained with other techniques. The superconducting pair-pair correlations at distances beyond nearest neighbor decrease monotonically with increasing Hubbard interaction U for all anisotropy, indicating the absence of frustration-driven superconductivity within the model.     

Quantum spreading of a self-gravitating wave-packet in singularity free gravity

In this paper we will study for the first time how the wave-packet of a self-gravitating meso-scopic system spreads in theories beyond Einstein’s general relativity. In particular, we will consider a ghost-free infinite derivative gravity, which resolves the 1 / r singularity in the potential – such that the gradient of the potential vanishes within the scale of non-locality. We will show that a quantum wave-packet spreads faster for a ghost-free and singularity-free gravity as compared to the Newtonian case, therefore providing us a unique scenario for testing classical and quantum properties of short-distance gravity in a laboratory in the near future.     

Crystal structure of a nucleoside analog: 9-(R)-[6-(R)-hydroxymethyl-1-oxa-4-thiacyclohexan-2-yl] adenine

The title compound (C₁₀H₁₃N₅O₂S,M _r=267.3) crystallizes in the orthorhombic space groupP2₁2₁2₁ witha=7.579(8),b=7.686(2) andc=20.941(4)Å,V=1220(1)ų,D _x=1.456 gm cm^–3,Z=4,=23.6 cm^–1,F(000)=560 andT=293 K. The structure was solved by direct methods and refined to aR value of 0.068 for 776 unique observed reflections. The oxathiane ring adopts a chair conformation. In the crystal structure the molecules are held together by hydrogen bonds and C-HO close contacts.     

Crystal and molecular structure ofp-aminobenzene sulfonacetamide sodium [sulfacetamide sodium] monohydrate

The crystal and molecular structure ofp-aminobenzene sulfonacetamide sodium, C₈H₉N₂NaO₃S·H₂O, an important substituted sulfa drug, has been determined from diffractometric data using MoK radiation. The crystals are monoclinic, witha=6.614(2),b=23.788(6),c=7.012(2) Å,=103.13(2)°, and space groupP2₁/c. The structure was solved by the heavyatom method, and refined by full-matrix least squares to a finalR value of 0.040 with 1435 unique reflections. In packing, the molecules form dimers through pairs of N-HN and N-HO hydrogen bonds. The molecules are further stabilized by O-HO and O-HN hydrogen bonds.     

Nuclear Halos and Efimov Effect: A Three-Body Approach

We present a brief review of our search for Efimov states and their evolutions in two-neutron halo nuclei ³²Ne and ³⁸Mg. We have tried to generalise the results by extending the calculations to a hypothetical case of a very heavy nucleus of mass 102 with a core of mass 100 and two valence neutrons.     

Particle physics models of inflation and curvaton scenarios

We review the particle theory origin of inflation and curvaton mechanisms for generating large scale structures and the observed temperature anisotropy in the cosmic microwave background (CMB) radiation. Since inflaton or curvaton energy density creates all matter, it is important to understand the process of reheating and preheating into the relevant degrees of freedom required for the success of Big Bang Nucleosynthesis. We discuss two distinct classes of models, one where inflaton and curvaton belong to the hidden sector, which are coupled to the Standard Model gauge sector very weakly. There is another class of models of inflaton and curvaton, which are embedded within Minimal Supersymmetric Standard Model (MSSM) gauge group and beyond, and whose origins lie within gauge invariant combinations of supersymmetric quarks and leptons. Their masses and couplings are all well motivated from low energy physics, therefore such models provide us with a unique opportunity that they can be verified/falsified by the CMB data and also by the future collider and non-collider based experiments. We then briefly discuss the stringy origin of inflation, alternative cosmological scenarios, and bouncing universes.     

Peculiarity of the $${}^{{12}}$$ C(0 $${{}^{+}}$$ ) and $${}^{{12}}$$ C(2 $${{}^{+}}$$ ) Energy Spectrum in a 3 $$\alpha$$ Model

Physics of Atomic Nuclei - Lowest energy spectrum of the $${}^{12}$$ C nucleus is analyzed in the 3 $$\alpha$$ -cluster model with a deep $$\alpha\alpha$$ potential of Buck, Friedrich and Wheatley...