A one-dimensional lattice model for a quantum mechanical free particle

Two types of particles, A and B with their corresponding antiparticles, are defined in a one dimensional cyclic lattice with an odd number of sites. In each step of time evolution, each particle acts as a source for the polarization field of the other type of particle with nonlocal action but with an effect decreasing with the distance: A -->...\bar{B} B \bar{B} B \bar{B} ... ; B --> A \bar{A} A \bar{A} A ... . It is shown that the combined distribution of these particles obeys the time evolution of a free particle as given by quantum mechanics.Comment: 8 pages. Revte

Employment Changes following Breast Cancer Diagnosis: The Effects of Race and Place

The financial implications of breast cancer diagnosis may be greater among rural and black women. Women with incident breast cancer were recruited as part of the Carolina Breast Cancer Study. We compared unadjusted and adjusted prevalence of cancer-related job or income loss, and a composite measure of either outcome, by rural residence and stratified by race. We included 2435 women: 11.7% were rural; 48.5% were black; and 38.0% reported employment changes after diagnosis. Rural women more often reported employment effects, including reduced household income (43.6% vs 35.4%, two-sided ?2 test P =. 04). Rural white, rural black, and urban black women each more often reported income reduction (statistically significant vs. urban white women), although these groups did not meaningfully differ from each other. In multivariable regression, rural differences were mediated by socioeconomic factors, but racial differences remained. Programs and policies to reduce financial toxicity in vulnerable patients should address indirect costs of cancer, including lost wages and employment

Shape evolution in even-mass 98−104^{98-104}Zr isotopes via lifetime measurements using the γγ\gamma \gamma -coincidence technique

International audienceThe Zirconium (Z = 40) isotopic chain has attracted interest for more than four decades. The abrupt lowering of the energy of the first $2^+$ state and the increase in the transition strength B(E2; $2^+_1\rightarrow 0^+_1)$ going from $^{98}$Zr to $^{100}$Zr has been the first example of “quantum phase transition” in nuclear shapes, which has few equivalents in the nuclear chart. Although a multitude of experiments have been performed to measure nuclear properties related to nuclear shapes and collectivity in the region, none of the measured lifetimes were obtained using the Recoil Distance Doppler Shift method in the $\gamma \gamma$-coincidence mode where a gate on the direct feeding transition of the state of interest allows a strict control of systematical errors. This work reports the results of lifetime measurements for the first yrast excited states in $^{98-104}$Zr carried out to extract reduced transition probabilities. The new lifetime values in $\gamma \gamma$-coincidence and $\gamma$-single mode are compared with the results of former experiments. Recent predictions of the Interacting Boson Model with Configuration Mixing, the Symmetry Conserving Configuration Mixing model based on the Hartree–Fock–Bogoliubov approach and the Monte Carlo Shell Model are presented and compared with the experimental data