Comments on “the (3He,d) reaction on28Si”

An assertion made in a recent paper dealing with the²⁸Si(³He,d) reaction to the 1/2⁺ ground state of²⁹P, namely that the spectroscopic factor extracted in the conventional way using DWBA analyses has a strong energy dependence, is shown to be due to a complication of inconsistent DWBA analyses by various authors, rather than being due to any intrinsic feature of the²⁸Si(³He,d) reaction mechanism.     

Ultrafast nonadiabatic dynamics: quasiclassical calculation of the transient photoelectron spectrum of I2(-).(CO2)8

In this paper we investigate the transient photoelectron spectrum of I2(-) in CO2 clusters recently measured by Neumark and co-workers. This work reveals a rich excited state dynamics with various competing electronic output channels. We find good agreement with experiments and we are able to relate the transient signal to different dynamical events that occur during the evolution of the cluster and its fragmentation products.     

Quantum simulation of systems with nodal surfaces

A modification of the diffusion Monte Carlo algorithm that enables the direct simulation of wave functions containing nodal surfaces is described. The use of orthogonality constraints during the simulation enables the properties of excited state systems to be calculated. For Fermi systems, spin variables and exchange operators are also included in the algorithm. The effectiveness of the methods is demonstrated using applications to several simple models.     

A Sharp Threshold for a Modified Bootstrap Percolation with Recovery

Bootstrap percolation is a type of cellular automaton on graphs, introduced as a simple model of the dynamics of ferromagnetism. Vertices in a graph can be in one of two states: ‘healthy’ or ‘infected’ and from an initial configuration of states, healthy vertices become infected by local rules. While the usual bootstrap processes are monotone in the sets of infected vertices, in this paper, a modification is examined in which infected vertices can return to a healthy state. Vertices are initially infected independently at random and the central question is whether all vertices eventually become infected. The model examined here is such a process on a square grid for which healthy vertices with at least two infected neighbours become infected and infected vertices with no infected neighbours become healthy. Sharp thresholds are given for the critical probability of initial infections for all vertices eventually to become infected.     

Communication: Partial linearized density matrix dynamics for dissipative, non-adiabatic quantum evolution

An approach for treating dissipative, non-adiabatic quantum dynamics in general model systems at finite temperature based on linearizing the density matrix evolution in the forward-backward path difference for the environment degrees of freedom is presented. We demonstrate that the approach can capture both short time coherent quantum dynamics and long time thermal equilibration in an application to excitation energy transfer in a model photosynthetic light harvesting complex. Results are also presented for some nonadiabatic scattering models which indicate that, even though the method is based on a "mean trajectory" like scheme, it can accurately capture electronic population branching through multiple avoided crossing regions and that the approach offers a robust and reliable way to treat quantum dynamical phenomena in a wide range of condensed phase applications.     

Analytical methods for determination of mycotoxins: An update (2009–2014)

Mycotoxins are a problematic and toxic group of small organic molecules that are produced as secondary metabolites by several fungal species that colonise crops. They lead to contamination at both the field and postharvest stages of food production with a considerable range of foodstuffs affected, from coffee and cereals, to dried fruit and spices. With wide ranging structural diversity of mycotoxins, severe toxic effects caused by these molecules and their high chemical stability the requirement for robust and effective detection methods is clear.     

208Pb(p, α)205Tl reaction at 16.475 MeV

The (p, α) reaction was studied on a²⁰⁸Pb target at 16.475 MeV. Nineteen states were observed in²⁰⁵Tl, up to 3.6 MeV in excitation. Angular distributions were obtained for five strong proton-hole transitions, and DWBA fits made to determinelj values. Results are compared with previous²⁰⁶Pb(t, α)²⁰⁵Tl,²⁰⁶Pb(d,³He)²⁰⁵Tl,²⁰⁵Tl(p, p′), and²⁰⁵Tl(n, n′) work.