Double handbag description of proton-antiproton annihilation into a heavy meson pair

We propose to describe the process $p \bar{p} \,\to\, \bar{D^0} D^0$ in a perturbative QCD motivated framework where a double-handbag hard process $u d \bar u \bar d \to \bar{c} c$ factorizes from transition distribution amplitudes, which are quasi forward hadronic matrix elements of $\Psi_q \Psi_q \Psi_c$ operators, where q denotes light quarks and c denotes the heavy quark. We advocate that the charm-quark mass acts as the large scale allowing this factorization. We calculate this process in the simplified framework of the scalar diquark model and present the expected cross sections for the PANDA experiment at GSI-FAIR.Comment: 25 page

D0ˉD0\bar{D^0} D^0-production in ppˉp\bar{p}-collisions within a double handbag approach

We estimate the scattering amplitude of the process $p \bar{p} \,\to\, \bar{D^0} D^0$ within a double-handbag framework where transition distribution amplitudes, calculated through an overlap representation, factorize from a hard subprocess. This process will be measured in the $\bar{\text{P}}\text{ANDA}$ experiment at GSI-FAIR.Comment: Talk given at the 11th International Conference on Low Energy Antiproton Physics (LEAP2013

Switched Control of Electron Nuclear Spin Systems

In this article, we study control of electron-nuclear spin dynamics at magnetic field strengths where the Larmor frequency of the nucleus is comparable to the hyperfine coupling strength. The quantization axis for the nuclear spin differs from the static B_0 field direction and depends on the state of the electron spin. The quantization axis can be switched by flipping the state of electron spin, allowing for universal control on nuclear spin states. We show that by performing a sequence of flips (each followed by a suitable delay), we can perform any desired rotation on the nuclear spins, which can also be conditioned on the state of the electron spin. These operations, combined with electron spin rotations can be used to synthesize any unitary transformation on the coupled electron-nuclear spin system. We discuss how these methods can be used for design of experiments for transfer of polarization from the electron to the nuclear spins

A comparison of Random Set and Point Estimate Methods in Finite Element Analysis of Tunnel Excavation

Risk and Reliability in Geotechnical Engineerin

Sustainability assessment of organic dairy farms in mountainous areas of Austria

Dairy farming plays a major role in mountainous regions of Austria, mostly due to high proportion of grasslands. In general, Austria’s dairy farming faces challenges regarding sustainability, e.g. environmental impacts, but specifically for alpine areas low productivity and dependency on direct payments are lowering sustainability. Organic farming is considered as a strategy to overcome these challenges. Considering this general background, we analysed the sustainability performance and its main drivers of organic dairy farms in mountainous regions of Austria

Critical connectedness of thin arithmetical discrete planes

An arithmetical discrete plane is said to have critical connecting thickness if its thickness is equal to the infimum of the set of values that preserve its $2$-connectedness. This infimum thickness can be computed thanks to the fully subtractive algorithm. This multidimensional continued fraction algorithm consists, in its linear form, in subtracting the smallest entry to the other ones. We provide a characterization of the discrete planes with critical thickness that have zero intercept and that are $2$-connected. Our tools rely on the notion of dual substitution which is a geometric version of the usual notion of substitution acting on words. We associate with the fully subtractive algorithm a set of substitutions whose incidence matrix is provided by the matrices of the algorithm, and prove that their geometric counterparts generate arithmetic discrete planes.Comment: 18 pages, v2 includes several corrections and is a long version of the DGCI extended abstrac