Fluorescence Spectroscopic Properties Analysed within the Extended Förster Theory with Application to Biomacromolecular Systems

The extended Förster theory (EFT) of electronic energy transport accounts for translational and rotational dynamics, which are neglected by the classical Förster theory (FT). EFT has been developed for electronic energy transfer within donor-acceptor pairs [Isaksson, et al, Phys. Chem. Chem. Phys., 9, 1941(2007)] and donor-donor pairs [Johansson, et al, J. Chem. Phys., 105, 10896 (1996); Norlin, et al, Phys. Chem. Chem. Phys., 10, 6962(2008)]. For donors that exhibit different or identical non-exponential fluorescence relaxation within a donor-donor pair, the process of reverberating energy migration is reversible to a higher or lower degree. Here the impact of the EFT has been studied with respect to its influence on fluorescence quantum yields, fluorescence lifetimes as well as depolarisation experiments. The FT predicts relative fluorescence quantum yields which usually agree with the EFT within experimental accuracy, however, substantial deviations occurs in the steady-state and in particular the time-resolved depolarisation data.     

Experimental determination of the scattering length for positron scattering from krypton

We report the first experimentally supported determination of the scattering length for positron scattering from krypton. Our result of  ?10.3 ± 1.5 a.u. compares favourably with that from a convergent close coupling calculation performed as a part of this investigation (?9.5 a.u.), and also with an earlier many body theory calculation of  ?10.1 a.u. from Gribakin and Ludlow [Phys. Rev. A 70, 032720 (2004)] and a polarized-orbital result of  ?10.4 a.u. from McEachran et al. [J. Phys. B 13, 1281 (1980)]. The present experimental scattering length supports the existence of a low-lying positron-krypton virtual state (Surko et al. [J. Phys. B 38, R57 (2005)]) at an energy ε = 0.13 eV.     

Inhomogeneous Heisenberg spin chain and quantum vortex filament as non-holonomically deformed NLS systems

Through the Hasimoto map, various dynamical systems can be mapped to different integrodifferential generalizations of Nonlinear Schrödinger (NLS) family of equations some of which are known to be integrable. Two such continuum limits, corresponding to the inhomogeneous XXX Heisenberg spin chain [J. Phys. C 15, L1305 (1982)] and that of a thin vortex filament moving in a superfluid with drag [Eur. Phys. J. B 86, 275 (2013) 86; Phys. Rev. E 91, 053201 (2015)], are shown to be particular non-holonomic deformations (NHDs) of the standard NLS system involving generalized parameterizations. Crucially, such NHDs of the NLS system are restricted to specific spectral orders that exactly complements NHDs of the original physical systems. The specific non-holonomic constraints associated with these integrodifferential generalizations additionally posses distinct semi-classical signature.     

Estimation of the nuclear distortion in the Coulomb breakup of 6Li into α + d in the field of 208Pb ion

In this article the results of the evaluation of the contribution of nuclear disintegration, based on the basis of diffraction theory in the ²⁰⁸Pb(⁶Li, αd)²⁰⁸Pb Coulomb breakup at an energy of 156 MeV is presented. Comparison of the results of the calculation with the experimental data of Kiener et al. [Phys. Rev. C 44, 2195 (1991)] gives evidence for the dominance of the Coulomb dissociation mechanism and contribution of nuclear distortion, but essentially smaller than the value reported byHammache et al. [Phys. Rev. C 82, 065803 (2010)] and Sümmerer [Prog. Part. Nucl. Phys. 66, 298 (2011)].     

Monopole, half-quantum vortex, and nexus in chiral superfluids and superconductors

Two exotic objects are still not identified experimentally in chiral superfluids and superconductors. These are the half-quantum vortex, which plays the part of the Alice string in relativistic theories [A. S. Schwarz, Nucl. Phys. B 208, 141 (1982)], and the hedgehog in the Î field, which is the counterpart of the Dirac magnetic monopole. These two objects of different dimensionality are topologically connected. They form a combined object which is called a nexus [John M. Cornwall, hep-th/9911125; Phys. Rev. D 59, 125015 (1999); Phys. Rev. D 58, 105028 (1998)] or center monopole [N. N. Chernodub, M. I. Polikarpov, A. I. Veselov and M. A. Zubkov, Nucl. Phys. Proc. Suppl. 73, 575 (1999)] in relativistic theories. Such a combination will permit the observation of half-quantum vortices and monopoles in several realistic geometries.     

Laser fields at flat interfaces: II. Plasmon resonances in aluminium photoelectron spectra

Using the model derived in paper I?[G. Ra?eev, Eur. Phys. J. D 66, 167 (2012)], this work presents calculations of the photoelectron spectrum (PES) of low index aluminium surfaces in the 10?C30?eV region. The laser is p or transverse magnetic linearly polarized incident on a flat structureless surface and its fields are modeled in I using the vector potential in the temporal gauge. This model uses a tensor and non-local isotropic (TNLI) susceptibility and solves the classical Ampère-Maxwell equation through the use of the vector potential from the electron density-coupled integro-differential equations (VPED-CIDE). The PE cross sections are the squares of the PE transition moments calculated using the VPED-CIDE vector potential function of the penetration coordinate. The PES is obtained in a one step model using either the Fermi golden rule or the Weisskopf-Wigner (WW) expressions. The WW cross section PES compares favorably with the experimental angle and energy resolved photoelectron yield (AERPY) spectrum of Levinson et?al. [Phys. Rev. Lett. 43, 952 (1979)], Levinson and Plummer [Phys. Rev. B 24, 628 (1981)] for Al(001) and of Barman et?al.?[Phys. Rev. B 58, R4285 (1998)], Barman [Curr. Sci. 88, 54 (2005)] for Al(111) surfaces. As in the experiment, our theoretical AERPY displays the multipole surface plasmon resonance at 11.32/12.75 eV for Al(001)/Al(111), mainly due to the surface contribution |??? _f |p·A|?? _i ?|², the bulk plasmon minimum at 15 eV and the two single particle excitation resonances at about 16 and 22 eV. The nature of the plasmon resonances of the PES is analyzed using the reflectance, the electron density induced by the laser and Feibelman??s parameter d _?? all introduced in paper?I.     

Basic kinetic wealth-exchange models: common features and open problems

We review the basic kinetic wealth-exchange models of Angle [J. Angle, Social Forces 65, 293 (1986); J. Math. Sociol. 26, 217 (2002)], Bennati [E. Bennati, Rivista Internazionale di Scienze Economiche e Commerciali 35, 735 (1988)], Chakraborti and Chakrabarti [A. Chakraborti, B. K. Chakrabarti, Eur. Phys. J. B 17, 167 (2000)], and of Dragulescu and Yakovenko [A. Dragulescu, V.M. Yakovenko, Eur. Phys. J. B 17, 723 (2000)]. Analytical fitting forms for the equilibrium wealth distributions are proposed. The influence of heterogeneity is investigated, the appearance of the fat tail in the wealth distribution and the relaxation to equilibrium are discussed. A unified reformulation of the models considered is suggested.     

The calculation of active Raman modes of α-quartz crystal via density functional theory based on B3LYP Hamiltonian in 6–311+G(2d) basis set?

We obtained an approximation of the force field of ??-quartz crystal using a new idea of applying density functional theory [J Purton, R Jones, C R A Catlow and M Leslie, Phys. Chem. Minerals 19, 392 (1993)]. Our calculations were based on B3LYP Hamiltonian [A N Lazarev and A P Mirgorodsky, Phys. Chem. Minerals 18, 231 (1991)] in 6?311+G(2d) basis set for H₁₆Si₇O₆ cluster and included a unit cell of the lattice. The advantage of our method is the increase in the speed of calculations and the better adaption of simulation results with the experimental data.     

On the supersymmetric partition function in QCD-inspired random matrix models

We show that the expression for the supersymmetric partition function of the chiral unitary (Laguerre) ensemble conjectured recently by Splittorff and Verbaarschot [Phys. Rev. Lett. 90, 041601 (2003)] follows from the general expression derived recently by Fyodorov and Strahov [J. Phys. A: Math. Gen. 36, 3203 (2003)].     

Structure of zero modes in a model of the discrete (2+1)-dimensional nonlinear Schrödinger equation

The structure of the zero modes in a discrete (2+1)-dimensional model of the gauge-invariant nonlinear Schrödinger equation is studied. Including the compactification of the Chern-Simons gauge fields eliminates the difficulties with the continuous model [L. A. Abramyan and A. P. Protogenov, JETP Lett. 64, 859 (1996); L. A. Abramyan, V. I. Berezhiani, and A. P. Protogenov, Phys. Rev. E 56, 6026 (1997)] and leads to a prediction of the existence of a transition region characterized by a hierarchical sequence of collapses which are enumerated by the Chern-Simons coefficient. Using the zero modes in calculating the dependence of the critical power N on the Chern-Simons coefficient, we have found that the transition region lies in the interval 11.703≤N≤12.01.     

Surface properties of the three-dimensional one-component plasma

Extending earlier work by us Badialiet al. [J. Phys. C: Solid State Phys. 16:2183 (1983)] we give further evidence for the usefulness of using spherical boundaries to calculate the bulk and surface properties of the three-dimensional onecomponent plasma (OCP) by Monte Carlo. Results are reported for the density profile of a “charged” OCP and for the pair distribution function parallel to the surface of an “open” system and of a neutral OCP near a hard wall. The charge fluctuations are calculated.     

Re-localization due to finite response times in a nonlinear Anderson chain

We study a disordered nonlinear Schr?dinger equation with an additional relaxation process having a finite response time ??. Without the relaxation term, ?? = 0, this model has been widely studied in the past and numerical simulations showed subdiffusive spreading of initially localized excitations. However, recently Caetano et al. [Eur. Phys. J. B 80, 321 (2011)] found that by introducing a response time ?? > 0, spreading is suppressed and any initially localized excitation will remain localized. Here, we explain the lack of subdiffusive spreading for ?? > 0 by numerically analyzing the energy evolution. We find that in the presence of a relaxation process the energy drifts towards the band edge, which enforces the population of fewer and fewer localized modes and hence leads to re-localization. The explanation presented here relies on former findings by Mulansky et al. [Phys. Rev. E 80, 056212 (2009)] on the energy dependence of thermalized states.     

Study of the polarization degree for the p ⃗ p → ppη measurement with WASA

Understanding of the production processes of the η meson will strongly rely on the precise determination of spin observables. So far these observables have been determined only for few excess energies and with low statistics (Winter et al. Eur. Phys. J. A18, 355 2003; Czyzykiewicz et al. Phys. Rev. Lett. 98, 122003 2007; Balestra et al. Phys. Rev. C69, 064003 2004). In the year 2010 WASA detector was used for the measurement of the \(\overrightarrow {p}p\rightarrow pp\eta \) reaction with the polarized proton beam of COSY (Moskal and Hodana J. Phys. Conf. Ser 295, 012080 2011). The measurement was done for the excess energy of Q = 15 MeV and Q = 72 MeV. In total about 10⁶ events corresponding to the \(\overrightarrow {p}p\rightarrow pp\eta \) reaction have been collected.     

Localization theory in zero dimension and the structure of the diffusion poles

The 1/[-iω + D(ω, q)q ²] diffusion pole in the localized phase transfers to the 1/ω Berezinskii-Gorkov singularity, which can be analyzed by the instanton method {M. V. Sadovski?, Zh. Éksp. Teor. Fiz. 83, 1418 (1982) [Sov. Phys. JETP 56, 816 (1982)] and J. L. Cardy, J. Phys. C 11, L321 (1978)}. When this approach is used directly, contradictions arise and do not disappear even if the problem is extremely simplified by taking the zero-dimensional limit. On the contrary, they are extremely sharpened in this case and become paradoxes. The main paradox is specified by the following statements: (i) the 1/ω singularity is determined by high orders of perturbation theory, (ii) the high-order behaviors for Φ^RA and U ^RA are the same, and (iii) Φ^RA has the 1/ω singularity, whereas U ^RA does not have it. Solution to the paradox indicates that the instanton method makes it possible to obtain only the 1/(ω + 2iγ) singularity, where the parameter γ remains indefinite and must be determined from additional conditions. This conceptually confirms the necessity of the self-consistent treatment of the diffusion coefficient used in the Vollhardt-Wölfle-type theories.     

The Ground State Energy of the Multi-Polaron in the Strong Coupling Limit

We consider the Fröhlich N-polaron Hamiltonian in the strong coupling limit and bound its ground state energy from below. In particular, our lower bound confirms that the ground state energy of the Fröhlich polaron and the ground state energy of the associated Pekar–Tomasevich variational problem are asymptotically equal in the strong coupling limit. We generalize the operator approach that was used to prove a similar result in the N =  1 case in Lieb and Thomas (Commun. Math. Phys. 183:511–519, 1997) and apply a Feynman–Kac formula to obtain the same result for an arbitrary particle number N ≥  1.     

Vision of nuclear physics with photo-nuclear reactions by laser-driven $\sf \gamma$ beams

A laser-accelerated dense electron sheet with an energy \(E=\tilde{\gamma} mc^2\) can be used as a relativistic mirror to coherently reflect a second laser with photon energy ?ω, thus generating by the Doppler boost [A. Einstein, Annalen der Physik 17, 891 (1905); D. Habs et al., Appl. Phys. B 93, 349 (2008)] brilliant high-energy photon beams with \(\hbar\omega^{\prime}=4\tilde{\gamma}^2\hbar\omega\) and short duration for many new nuclear physics experiments.While the shortest-lived atomic levels are in the atto-second range, nuclear levels can have lifetimes down to zeptoseconds. We discuss how the modulation of electron energies in phase-locked laser fields used for as-measurements [E. Goulielmakis et al., Science 317, 769 (2007)] can be carried over to the new direct measurement of fs–zs nuclear lifetimes by modulating the energies of accompanying conversion electrons or emitted protons. In the field of nuclear spectroscopy we discuss the new perspective as a function of increasing photon energy. In nuclear systems a much higher sensitivity is predicted to the timevariation of fundamental constants compared to atomic systems [V. Flambaum, arXiv:nucl-th/0801.1994v1 (2008)]. For energies up to 50 keV Mössbauer-like recoilless absorption allows to produce nuclear bosonic ensembles with many delocalized coherent polaritons [G.V. Smirnov et al., Phys. Rev. A 71, 023804 (2005)] for the firsttime. Using the (γ,n) reaction to produce cold, polarized neutrons with a focusing ellipsoidal device [P. Böni, Nucl. Instrum. Meth. A 586, 1 (2008); Ch. Schanzer et al., Nucl. Instrum. Meth. 529, 63 (2004)], brilliant cold polarized micro-neutron beams become available. The compact and relatively cheap laser-generated γ beams may serve forextended studies at university-based facilities.     

On the determination of the mutual exclusion statistics parameter

Following the generalized definition of exclusion statistics to infinite-dimensional Hilbert space [Murthy and Shankar, Phys. Rev. Lett. 72, 3629 (1994)] for a single-component anyonic system, we derive a simple relation between second mixed virial coefficient and the mutual exclusion statistics parameters using high-temperature expansion method for multicomponent anyonic system. The above result is derived without working in a specific model and is valid in any spatial dimensions.