Three-nucleon force at large distances: Insights from chiral effective field theory and the large-N_c expansion

We confirm the claim of Ref. [D.R. Phillips, C. Schat, Phys. Rev. C88 (2013) 3, 034002] that 20 operators are sufficient to represent the most general local isospin-invariant three-nucleon force and derive explicit relations between the two sets of operators suggested in Refs. [D.R. Phillips, C. Schat, Phys. Rev. C88 (2013) 3, 034002] and [H. Krebs, A.M. Gasparyan, E. Epelbaum, Phys.Rev. C87 (2013) 5, 054007]. We use the set of 20 operators to discuss the chiral expansion of the long- and intermediate-range parts of the three-nucleon force up to next-to-next-to-next-to-next-to-leading order in the standard formulation without explicit Delta(1232) degrees of freedom. We also address implications of the large-N_c expansion in QCD for the size of the various three-nucleon force contributions.Comment: 15 pages, 6 figure

Isospin-breaking two-nucleon force with explicit Delta-excitations

We study the leading isospin-breaking contributions to the two-nucleon two-pion exchange potential due to explicit Delta degrees of freedom in chiral effective field theory. In particular, we find important contributions due to the delta mass splittings to the charge symmetry breaking potential that act opposite to the effects induced by the nucleon mass splitting.Comment: 10 pages, 4 figure

On Matrix Product States for Periodic Boundary Conditions

The possibility of a matrix product representation for eigenstates with energy and momentum zero of a general m-state quantum spin Hamiltonian with nearest neighbour interaction and periodic boundary condition is considered. The quadratic algebra used for this representation is generated by 2m operators which fulfil m^2 quadratic relations and is endowed with a trace. It is shown that {\em not} every eigenstate with energy and momentum zero can be written as matrix product state. An explicit counter-example is given. This is in contrast to the case of open boundary conditions where every zero energy eigenstate can be written as a matrix product state using a Fock-like representation of the same quadratic algebra.Comment: 7 pages, late

On-shell consistency of the Rarita-Schwinger field formulation

We prove that any bilinear coupling of a massive spin-3/2 field can be brought into a gauge invariant form suggested by Pascalutsa by means of a non-linear field redefinition. The corresponding field transformation is given explicitly in a closed form and the implications for chiral effective field theory with explicit Delta (1232) isobar degrees of freedom are discussed.Comment: 9 pages, 1 figur

Folklore, Fear, and the Feminine: Ghosts and Old Wives' Tales in Wuthering Heights

Folk sources and narratives underlie much of Wuthering Heights

Olive Schreiner's Racialization of South Africa

South African novelist and essayist Olive Schreiner interpreted South African racial and class categories for British readers in an effort to prevent what she worried would be bloody conflict between Boers and indigenous Africans

Überprüfung der Bezugskurven der Schweizer Version des Freiburger Zahlen- und Einsilbertests

Zusammenfassung: Hintergrund: Die Schweizer Ausgabe des Freiburger Sprachverständlichkeitstests unterscheidet sich von der deutschen Version u.a. durch den Ersatz von 5 in der Schweiz ungebräuchlichen einsilbigen Testworten. Zudem wird keine Freifeldentzerrung benutzt und die die sich aus dem Freifeldübertragungsmaß ergebende Differenz von 6dB zwischen Lautsprecher und Kopfhörer wird bei der Kalibrierung nicht berücksichtigt. Der vor einiger Zeit eingeführte Pegelausgleich zwischen den Prüfworten und Anpassungen in der Kalibrierung veranlassten uns zur Überprüfung der Bezugskurven. Patienten/Methoden: Bei 20 normal hörenden Versuchpersonen wurde das Sprachverstehen von Zahlen und einsilbigen Wörtern mit Kopfhörern und Lautsprechern geprüft. Ergebnisse: Der Pegel für 50% Sprachverstehen lag bei Lautsprecherdarbietung im Mittel um 7,5dB niedriger ist als bei Kopfhörerdarbietung. Die mittlere Pegeldifferenz zwischen Zahlen und Einsilbern betrug 9,6dB, liegt also deutlich unter den 14dB der heute in der Schweiz empfohlenen Bezugskurven. Fazit: Die heute in der Schweiz empfohlenen Bezugskurven stimmen für Einsilber bei Kopfhörerdarbietung gut mit unseren Messungen überein, nicht aber für Zahlen und bei Lautsprecherdarbietun

Concentration for One and Two Species One-Dimensional Reaction-Diffusion Systems

We look for similarity transformations which yield mappings between different one-dimensional reaction-diffusion processes. In this way results obtained for special systems can be generalized to equivalent reaction-diffusion models. The coagulation (A + A -> A) or the annihilation (A + A -> 0) models can be mapped onto systems in which both processes are allowed. With the help of the coagulation-decoagulation model results for some death-decoagulation and annihilation-creation systems are given. We also find a reaction-diffusion system which is equivalent to the two species annihilation model (A + B ->0). Besides we present numerical results of Monte Carlo simulations. An accurate description of the effects of the reaction rates on the concentration in one-species diffusion-annihilation model is made. The asymptotic behavior of the concentration in the two species annihilation system (A + B -> 0) with symmetric initial conditions is studied.Comment: 20 pages latex, uuencoded figures at the en