Measurement of the resonant d(mu)t molecular formation rate in solid HD

Measurements of muon-catalyzed dt fusion ( d(mu)t-->4He + n + mu(-)) in solid HD have been performed. The theory describing the energy dependent resonant molecular formation rate for the reaction (mu)t + HD-->[(d(mu)t)pee](*) is compared to experimental results in a pure solid HD target. Constraints on the rates are inferred through the use of a Monte Carlo model developed specifically for the experiment. From the time-of-flight analysis of fusion events in 16 and 37 microg x cm(-2) targets, an average formation rate consistent with 0.897+/-(0.046)(stat)+/-(0.166)(syst) times the theoretical prediction was obtained.     

Semi-Classical Dynamics in Quantum Spin Systems

We consider two limiting regimes, the large-spin and the mean-field limit, for the dynamical evolution of quantum spin systems. We prove that, in these limits, the time evolution of a class of quantum spin systems is determined by a corresponding Hamiltonian dynamics of classical spins. This result can be viewed as a Egorov-type theorem. We extend our results to the thermodynamic limit of lattice spin systems and continuum domains of infinite size, and we study the time evolution of coherent spin states in these limiting regimes.     

A real-space perturbation theory for electronic correlation

We introduce a method for treating electronic correlation in which a correlation factor is optimized using Hylleraas variational perturbation theory. The factor is defined by a number of parameters which grows only linearly with system size. We test the theory on two-electron atoms using the shielded-nucleus Hamiltonian at zeroth order, obtaining −2.9035 a.u. for helium. The convergence of the method is investigated, and energies and intracule densities are compared with accurate variational results. The application of the theory to an N-electron problem with a Hartree–Fock Hamiltonian at zeroth order is discussed.     

Gender in mathematics relationality: counseling underprepared college students

As a professional tutor practicing primarily in the Northeast of the USA, I have noticed gender differences in how college students approach required mathematics courses and in how I approach tutoring them. I conducted a relational mathematics counseling pilot study, where I was a participant researcher in an introductory statistics for psychology class, ran a study group for the class, and offered individual tutor-counseling to ten volunteer participants, four males, and six females. I found that while students’ expressions of gender were unique and more or less salient to their mathematical progress, there were also some patterns of interest. My analysis suggests that gender difference in underprepared students, on whom I focus in this paper, was a key in the development of differing efforts to protect underdeveloped mathematics selves: typically overconfident grandiosity and/or resistance in the men and underconfident depression or anxiety and troubled tutor attachment relationships in the women. To the concomitant question with respect to effective support that emerged, I show that key relational changes I made and approaches I developed to help, needed also to be gender-sensitive.     

Bestimmung des Aluminiums

Ohne Zusammenfassung     

Die Bestimmung des Urans

Ohne Zusammenfassung     

A linked electron pair functional

A modification of the variational configuration interaction functional in the first-order interacting space for molecular electronic structure is presented. The modified functional is a fully linked expression that by construction is extensive and invariant to transformations of the underlying orbital basis and is exact for an ensemble of separated two-electron subsystems. In addition, an approximation to variational coupled cluster is generated through truncation of the exponential cluster operator. When combined, these methods demonstrate accuracy that exceeds that of the standard coupled-cluster method, in particular in situations where the reference Slater determinant is not a good approximation.