Coupled-channel pseudo-potential description of the Feshbach resonance in two dimensions

We derive pseudo-potentials that describe the scattering between two particles in two spatial dimensions for any partial wave m, whose scattering strength is parameterized in terms of the m-dependent phase shift. Using our m=0 pseudo-potential, we develop a coupled channel model with 2D zero-range interactions, which describes the two-body physics across a Feshbach resonance. Our model predicts the scattering length, the binding energy and the "closed channel molecular fraction" of two particles; these observables can be measured in experiments on ultracold quasi-2D atomic Bose and Fermi gases with present-day technology.Comment: 4 pages, 3 figure

Structure and spectroscopy of doped helium clusters using quantum Monte Carlo techniques

We present a comparative study of the rotational characteristics of various molecule-doped 4He clusters using quantum Monte Carlo techniques. The theoretical conclusions obtained from both zero and finite temperature Monte Carlo studies confirm the presence of two different dynamical regimes that correlate with the magnitude of the rotational constant of the molecule, i.e., fast or slow rotors. For a slow rotor, the effective rotational constant for the molecule inside the helium droplet can be determined by a microscopic two-fluid model in which helium densities computed by path integral Monte Carlo are used as input, as well as by direct computation of excited energy levels. For a faster rotor, the conditions for application of the two-fluid model for dynamical analysis are usually not fulfilled and the direct determination of excitation energies is then mandatory. Quantitative studies for three molecules are summarized, showing in each case excellent agreement with experimental results

Pseudo-potential treatment of two aligned dipoles under external harmonic confinement

Dipolar Bose and Fermi gases, which are currently being studied extensively experimentally and theoretically, interact through anisotropic, long-range potentials. Here, we replace the long-range potential by a zero-range pseudo-potential that simplifies the theoretical treatment of two dipolar particles in a harmonic trap. Our zero-range pseudo-potential description reproduces the energy spectrum of two dipoles interacting through a shape-dependent potential under external confinement very well, provided that sufficiently many partial waves are included, and readily leads to a classification scheme of the energy spectrum in terms of approximate angular momentum quantum numbers. The results may be directly relevant to the physics of dipolar gases loaded into optical lattices.Comment: 9 pages, 4 figure

Examining the Effects of Aspects of Resiliency and Vulnerability on the Relationship Between Experiencing Microaggressions and Mental Health Among Persons of Color

Ethnic minorities experience discrimination frequently, especially a subtle form of discrimination called microaggressions-which are linked with poorer mental health. This study examined protective factors against microaggressions. In this study, responding to microaggressions actively (as opposed to ignoring the situation) was linked with better mental health. When use of active coping strategies was low, microaggressions were associated with lower self-esteem and higher depression and anxiety. Alternatively, when use of active coping styles was high, microaggressions were associated with higher self-esteem and less depression, anxiety, and drug use. Responding to microaggressions is a disengaged way (such as attempting to ignore or avoid the situation) was consistently linked with worse mental health, including lower self-esteem and higher depression, anxiety, and substance use. Participants were randomly assigned to one of two conditions to examine emotional impacts of microaggressions. Experimental group participants wrote about recent microaggressions, whereas control condition participants wrote about a neutral activity. Participants who wrote about microaggressions reported higher negative emotions. Higher use of active coping styles was associated with higher positive emotions. Alternatively, when the use of disengaged coping strategies was high, positive emotions decreased among experimental condition participants. Results suggest that the healthiest way to manage discrimination is to use active coping (such as addressing or attempting to change the situation, seeking support from friends or family, trying to view the other person\u27s motives and behavior in a more positive light, or using humor to lighten the situation) rather than disengaged (such as distraction, denial, avoidance, or using drugs)