Ordered bicontinuous double-diamond morphology in subsaturation nuclear matter

We propose to identify the new "intermediate" morphology in subsaturation nuclear matter observed in a recent quantum molecular dynamics simulation with the ordered bicontinuous double-diamond structure known in block copolymers. We estimate its energy density by incorporating the normalized area-volume relation given in a literature into the nuclear liquid drop model. The resulting energy density is higher than the other five known morphologies.Comment: 4 pages, 4 figures, published in Phys. Rev.

Solvable few-body quantum problems

This work is devoted to the study of some exactly solvable quantum problems of four, five and six bodies moving on the line. We solve completely the corresponding stationary Schr\"odinger equation for these systems confined in an harmonic trap, and interacting pairwise, in clusters of two and three particles, by two-body inverse square Calogero potential. Both translationaly and non-translationaly invariant multi-body potentials are added. In each case, the full solutions are provided, namely the normalized regular eigensolutions and the eigenenergies spectrum. The irregular solutions are also studied. We discuss the domains of coupling constants for which these irregular solutions are square integrable. The case of a "Coulomb-type" confinement is investigated only for the bound states of the four-body systems.Comment: 23 page

A Generalized Uhlenbeck and Beth Formula for the Third Cluster Coefficient

Relatively recently (A. Amaya-Tapia, S. Y. Larsen and M. Lassaut. Ann. Phys., vol. 306 (2011) 406), we presented a formula for the evaluation of the third Bose fugacity coefficient - leading to the third virial coefficient - in terms of three-body eigenphase shifts, for particles subject to repulsive forces. An analytical calculation for a 1-dim. model, for which the result is known, confirmed the validity of this approach. We now extend the formalism to particles with attractive forces, and therefore must allow for the possibility that the particles have bound states. We thus obtain a true generalization of the famous formula of Uhlenbeck and Beth (G.E. Uhlenbeck and E. Beth. Physica, vol. 3 (1936) 729; E. Beth and G.E. Uhlenbeck. ibid, vol.4 (1937) 915) (and of Gropper (L. Gropper. Phys. Rev. vol. 50 (1936) 963; ibid vol. 51 (1937) 1108)) for the second virial. We illustrate our formalism by a calculation, in an adiabatic approximation, of the third cluster in one dimension, using McGuire's model as in our previous paper, but with attractive forces. The inclusion of three-body bound states is trivial; taking into account states having asymptotically two particles bound, and one free, is not.Comment: 38 pages, 6 figure

Cluster Expansion of Cold Alpha Matter Energy

In the cluster expansion framework of Bose liquids we calculate analytical expressions of the two-body, three-body and four-body diagrams contributing to the g.s. energy of an infinite system of neutral alpha-particles at zero-temperature, interacting via the strong nuclear forces exclusively. This is analytically tractable by assuming a density dependent two-body correlation function of Gaussian type. For the alpha-alpha potential we adopt the phenomenological Ali-Bodmer interaction and semi-microscopic potentials obtained from the Gogny force parametrizations. We show that under such assumptions we achieve a rapid convergence in the cluster expansion, the four-body contributions to the energy being smaller than the two-body and three-body contributions by at least an order of magnitude.Comment: 22 pages, 13 figure

Piecewise constant potentials and discrete ambiguities

This work is devoted to the study of discrete ambiguities. For parametrized potentials, they arise when the parameters are fitted to a finite number of phase-shifts. It generates phase equivalent potentials. Such equivalence was suggested to be due to the modulo $\pi$ uncertainty inherent to phase determinations. We show that a different class of phase-equivalent potentials exists. To this aim, use is made of piecewise constant potentials, the intervals of which are defined by the zeros of their regular solutions of the Schr\"odinger equation. We give a classification of the ambiguities in terms of indices which include the difference between exact phase modulo $\pi$ and the numbering of the wave function zeros.Comment: 26 pages Subject: Mathematical Physics math-p

Ising analogue to compact-star matter

By constructing an Ising analogue of compact-star matter at sub-saturation density we explored the effect of Coulomb frustration on the nuclear liquid-gas phase transition. Our conclusions is twofold. First, the range of temperatures where inhomogeneous phases form expands with increasing Coulomb-field strength. Second, within the approximation of uniform electron distribution, the limiting point upon which the phase-coexistence region ends does not exhibit any critical behaviour. Possible astrophysics consequences and thermodynamical connections are discussed.Comment: 4 pages, 3 figure

European protection of agricultural products and foodstuffs in the new EU member countries : the example of collaboration between France and Slovenia

The objective of this article is to present the main results of an advising and assisting program, which took place in years 2001 until 2003, and which involved the Slovenian Ministry for Agriculture and two French institutions, French Agency for Standardization and National Institute for Designations of Origin. Authors report their experience in implementation of a system for the registration and certification of special agricultural products and foodstuffs in the Republic of Slovenia, in accordance with the quality policy and legislation of the European union (Council Regulations 2081/92 and 2082/92). They highlight the key success factors for an efficient implementation of the registration system for the special agricultural products and foodstuffs in the new EU members

EVROPSKA ZAŠČITA POIMENOVANJ ZA POSEBNE KMETIJSKE PROIZVODE IN ŽIVILA V NOVIH ČLANICAH EU. PRIMER SODELOVANJA MED FRANCIJO IN SLOVENIJO

The objective of this article is to present the main results of an advising and assisting program, which took place in years 2001 until 2003, and which involved the Slovenian Ministry of Agriculture, Forestry and Food and two French institutions, French Agency for Standardization and National Institute for Designations of Origin. Authors report their experience in implementation of a system for the registration and certifi cation of special agricultural products and foodstuffs in the Republic of Slovenia, in accordance with the quality policy and legislation of the European union (Council Regulations 2081/92 and 2082/92). They highlight the key success factors for an effi cient implementation of the registration system for the special agricultural products and foodstuffs in the new EU members.V članku so predstavljeni glavni rezultati programa Phare, ki je potekal v letih 2001 do 2003 med slovenskim Ministrstvom za kmetijstvo, gozdarstvo in prehrano ter dvema francoskima institucijama, in sicer Agencijo za standardizacijo in inštitutom INAO (nacionalni inštitut za poimenovanja porekla). Avtorji poročajo o izkušnjah pri implementaciji sistema registracije in certifi kacije posebnih kmetijskih proizvodov in živil v Republiki Sloveniji skladno s politiko kakovosti in zakonodajo Evropske unije (Uredba Sveta 2081/92 in 2082/92). Posebej so poudarjeni ključni dejavniki za učinkovito implementacijo sistema zaščite posebnih kmetijskih proizvodov in živil ter uspešnost tovrstne zaščite v novih članicah Evropske unije

The size of two-body weakly bound objects : short versus long range potentials

The variation of the size of two-body objects is investigated, as the separation energy approaches zero, with both long range potentials and short range potentials having a repulsive core. It is shown that long range potentials can also give rise to very extended systems. The asymptotic laws derived for states with angular momentum l=1,2 differ from the ones obtained with short range potentials. The sensitivity of the asymptotic laws on the shape and length of short range potentials defined by two and three parameters is studied. These ideas as well as the transition from the short to the long range regime for the l=0 case are illustrated using the Kratzer potential.Comment: 5 pages, 3 figures, submitted to Physical Review Letter

Anyonic Excitations in Fast Rotating Bose Gases Revisited

The role of anyonic excitations in fast rotating harmonically trapped Bose gases in a fractional Quantum Hall state is examined. Standard Chern-Simons anyons as well as "non standard" anyons obtained from a statistical interaction having Maxwell-Chern-Simons dynamics and suitable non minimal coupling to matter are considered. Their respective ability to stabilize attractive Bose gases under fast rotation in the thermodynamical limit is studied. Stability can be obtained for standard anyons while for non standard anyons, stability requires that the range of the corresponding statistical interaction does not exceed the typical wavelenght of the atoms.Comment: 5 pages. Improved version to be published in Phys. Rev. A, including a physical discussion on relevant interactions and scattering regime together with implication on the nature of statistical interactio