On the 18O positive-parity rotational band

Deuteron-alpha angular correlations have been measured for the reaction ${}^{14}\text{C}\text{(}{}^6\text{Li,d}\text{)}{}^{18}\text{O}{}^1\text{→α}{}_0\text{+}{}^{14}\text{C at}\text{E(}{}^6\text{Li}\text{)=34}\text{MeV}$ and θ_d^lab=10°. Transitions involving the 11.69 MeV (6⁺) and the 17.6±0.2 MeV ¹⁸O states have been analyzed. Spin and parity are confirmed for the known 11.69 MeV (6⁺) state and assigned to be 8⁺ for the 17.6 MeV level. This last is suggested to be the fifth member of the positive-parity ¹⁸O rotational band built on the 3.63 MeV (0⁺) level.     

Propagators for time-dependent linear and quadratic potentials and inverse Weierstrass transform

It is shown that the inversion of the Weierstrass transform allows obtaining the propagator without an explicit knowledge of an orthonormal complete system of solutions. The cases of the time-dependent linear and quadratic potentials are investigated in some detail.     

A Purely Geometric Approach to the Problem of Computing the Projection of a Point on a Simplex

In this short note, we present a new proof of a classical algorithm for finding the projection of a point on the standard simplex. The new proof is based only on elementary geometric arguments.     

Gap orders of rational functions on plane curves with few singular points

We prove that certain integers n cannot occur as degrees of linear series without base points on the normalization of a plane curve whose only singularities are a “small” number of nodes and ordinary cusps. As a consequence we compute the gonality of such a curve. Work done with financial support of M.U.R.S.T. while the authors were members of C.N.R.     

Some remarks on the Walras equilibrium problem in Lebesgue spaces

We introduce a parametric variational inequality in order to model the time dependent Walras economic equilibrium and discuss its relation with an integral formulation in the spaces (L ^∞, L ¹). The role of monotonicity is analysed and, as a classical example, we study the Walras problem using the Cobb–Douglas functions in this new functional setting.     

<Superscript>18</Superscript>Ne diproton decay

Two proton radioactivity studies have been performed on excited states of ¹⁸Ne produced, among other fragments, by ²⁰Ne projectile fragmentation and excited via Coulomb excitation on a Pb target. Every incoming ion was tagged before interacting with the lead target on an event by event basis in order to discriminate the secondary reactions according to the projectile. Decay of ¹⁸Ne levels has been studied by complete kinematical reconstruction. In spite of the low statistics a couple of events looks very promising for two proton correlated emission.     

Chirality Enhancement of Porphyrin Supramolecular Assembly Driven by a Template Preorganization Effect

Cationic polylysine promotes, under neutral conditions, the spontaneous aggregation of opposite charged ZnTPPS in water. Spectroscopic investigations evidence a different preorganization of ZnTPPS onto the polypeptide matrix depending on the chain length. Spinodal decomposition theory in confined geometry is used to model this mechanism by considering the time evolution of a homogeneous distribution of randomly adsorbed particles (porphyrins) onto a rodlike polyelectrolyte (polymer) of variable length L.