Daniel Vrinceanu

Padé reconstruction of Regge poles from scattering matrix data for chemical reactions

Abstract We describe a practical procedure for analytically continuing a scattering matrix element into the complex angular momentum plane, given its values at the physical angular momentum quantum numbers of 0, 1, 2, …. The procedure first applies a preconditioning function to the scattering matrix element; then the remaining residual function is interpolated using Pade approximations. The method is illustrated by extracting the leading Regge pole position and residue for the state selected reactions Cl+HCl(v=1, j=5) → ClH(v′=1, j′=5)+Cl and I+HI(v=0, j=0) → IH(v′=0, j′=2)+I, where v and j are vibrational and rotational quantum numbers respectively.

Linear dielectric response of clustered living cells

The dielectric behavior of a linear cluster of two or more living cells connected by tight junctions is analyzed using a spectral method. The polarizability of this system is obtained as an expansion over the eigenmodes of the linear response operator, showing a clear separation of geometry from electric parameters. The eigenmode with the second largest eigenvalue dominates the expansion as the junction between particles tightens, but only when the applied field is aligned with the cluster axis. This effect explains a distinct low-frequency relaxation observed in the impedance spectrum of a suspension of linear clusters.

Surface Plasmon Resonances of Clustered Nanoparticles

Linear clusters made by tightly connecting two or more metallic nanoparticles have new types of surface plasmon resonances as compared with isolated nanoparticles. These new resonances are sensitive to the size of the junction and to the number of interconnected particles and are described by eigenmodes of a boundary integral equation. This formulation allows effective separation of geometric and shape contribution from electric properties of the constituents. Results for particles covered by a thin shell are also provided highlighting ultrasensitive sensing applications. The present analysis sheds a new light on the interpretation of recent experiments.

Long-range interactions for Ηe(nS)-He(n'S) and He(nS)-He(n'P)

The energetically lowest five states of a helium atom are: He(

Orthogonal polynomial projection quantization: a new Hill determinant method

1^1S

The variable phase method used to calculate and correct scattering lengths

), He(

COMPREHENSIVE RATE COEFFICIENTS FOR ELECTRON-COLLISION-INDUCED TRANSITIONS IN HYDROGEN

2^3S

Electron wave filters from inverse scattering theory

), He(

Long-range interactions between aHe(2S3)atom and aHe(2P3)atom for like isotopes

2^1S

The King model for electrons in a finite-size ultracold plasma

), He(