Towards a fitting procedure for deeply virtual Compton scattering at next-to-leading order and beyond

Combining dispersion and operator product expansion techniques, we derive the conformal partial wave decomposition of the virtual Compton scattering amplitude in terms of complex conformal spin to twist-two accuracy. The perturbation theory predictions for the deeply virtual Compton scattering (DVCS) amplitude are presented in next-to-leading order for both conformal and modified minimal subtraction scheme. Within a conformal subtraction scheme, where we exploit predictive power of conformal symmetry, the radiative corrections are presented up to next-to-next-to-leading order accuracy. Here, because of the trace anomaly, the mixing of conformal moments of generalized parton distributions (GPD) at the three-loop level remains unknown. Within a new proposed parameterization for GPDs, we then study the convergence of perturbation theory and demonstrate that our formalism is suitable for a fitting procedure of DVCS observables.Comment: LaTeX, 100 pages, 16 figures, 5 tables; Secs. 5.1 and 5.2 revised, minor corrections, version to be published in Nucl.Phys.

Conformational and phase behavior of comb copolymer brushes : a theoretical study

iii+160hlm.;24c

Comb Copolymer Brush with Chemically Different Side Chains

An investigation of side chain microphase separation within a single comb copolymer molecule containing chemically different A and B side chains has been carried out. Expressions for the transition point χ*AB in a good (χ*AB ~ N-3/8), marginal (χ*AB ~ N-1/2), θ (χ*AB ~ N-2/3), and poor (χ*AB ~ N-1) solvent are derived both by a mean field calculation and by scaling arguments. Properties of the system below and above the transition point are described. Some unusual “bowlike” conformations are predicted for a single molecule in the microphase separated state in a good solvent.

Strongly adsorbed comb copolymers with rigid side chains

We study the conformational behavior in a plane of a comb copolymer molecule, consisting of a semiflexible backbone and rigid side chains interacting via a van der Waals potential. Using a mean-field approach, two different regimes are distinguished depending on the strength of the attraction between the side chains. In the weak attraction limit the side chains are oriented preferably perpendicular to the backbone. The persistence length λ of the comb copolymer molecule scales as the second power of the length of the side chain L: λ ∝L2. In the strong attraction limit all side chains become strongly tilted and the persistence length scales as λ ∝L4. The nonlinear bending regime is also studied and characterized by a change in structure and a decreasing moment of bending force as a function of curvature, i.e., bending becomes easier.

Food as a marker for economy and part of identity: traditional vegetal food of Yezidis and Kurds in Armenia

Background: The traditional food of the Yezidis and Kurds of Armenia has some particularities and differences compared with the traditional cuisine of Armenians. Methods: Ethnobotanical data collected during fieldworks in 2013–2015 in Armenia via interviews, direct observations and sampling of used plants for identification of species. Results: Traditional dishes of Yezidis and Kurds are simple. They are mostly made from or contain as a main component lamb and milk products (sometimes beef and chicken, but never pork). The main vegetal components of their traditional food are represented by cultivated cereals, grains, and herbs of wild plants. Edible plants gathered from the wild are used primarily for nutritional purposes, for flavoring prepared meals and milk products, and for tea. Discussion: We correlate these distinctions with the transhumant pastoral lifestyle of the Yezidi and Kurdish people