Feshbach Molecules in a One-dimensional Optical Lattice

We present the theory of a pair of atoms in a one-dimensional optical lattice interacting via a narrow Feshbach resonance. Using a two-channel description of the resonance, we derive analytic results for the scattering states inside the continuum band and the discrete bound states outside the band. We identify a Fano resonance profile, and the survival probability of a molecule when swept through the Bloch band of scattering states by varying an applied magnetic field. We discuss how these results may be used to investigate the importance of the structured nature of the continuum in experiments.Comment: 4 pages, 3 figure

Two-channel Feshbach physics in a structured continuum

We analyze the scattering and bound state physics of a pair of atoms in a one-dimensional optical lattice interacting via a narrow Feshbach resonance. The lattice provides a structured continuum allowing for the existence of bound dimer states both below and above the continuum bands, with pairs above the continuum stabilized by either repulsive interactions or their center of mass motion. Inside the band the Feshbach coupling to a closed channel bound state leads to a Fano resonance profile for the transmission, which may be mapped out by RF- or photodissociative spectroscopy. We generalize the scattering length concept to the one-dimensional lattice, where a scattering length may be defined at both the lower and the upper continuum thresholds. As a function of the applied magnetic field the scattering length at either band edge exhibits the usual Feshbach divergence when a bound state enters or exits the continuum. Near the scattering length divergences the binding energy and wavefunction of the weakly bound dimer state acquires a universal form reminiscent of those of free-space Feshbach molecules. We give numerical examples of our analytic results for a specific Feshbach resonance, which has been studied experimentally.Comment: 18 pages, 9 embedded figure

Scattering and binding of different atomic species in a one-dimensional optical lattice

The theory of scattering of atom pairs in a periodic potential is presented for the case of different atoms. When the scattering dynamics is restricted to the lowest Bloch band of the periodic potential, a separation in relative and average discrete coordinates applies and makes the problem analytically tractable, and we present a number of new results and features compared to the case of identical atoms.Comment: 5 pages, 4 figure

THE EFFECT OF LANGUAGE BARRIERS ON VARIATION AND RECEIPT OF EARLY STAGE BREAST CANCER TREATMENT

Background: Arriving at and implementing an appropriate patient centered treatment plan for early stage breast cancer requires significant dialogue between healthcare providers and patients. How language barriers affect this process has not been thoroughly explored in the literature. The aim of this paper is to examine the effect of language barrier on variation and receipt of early stage breast cancer treatment. Methods: Rates of lumpectomy, mastectomy, and contralateral prophylactic mastectomy (CPM) with or without reconstruction were compared between English speaking and Low English Proficiency (LEP) cohorts. Patients with recurrent or bilateral breast cancer, male patients, and/or known genetic mutations were excluded. Receipt of recommended treatments including chemotherapy, hormonal therapy and radiation were compared between the two groups, as well as patient refusal and loss of follow-up. Regression analysis for all-cause mortality within this time period was tabulated for each group. Results: There were no significant differences between receipt of recommended treatments, patient refusal or loss of follow up between the cohorts. LEP patients had a greater proportion of lumpectomies (79.7 versus 70.7%) while 9.2% of English-speaking patients had CPM or CPM with reconstruction compared to none of the LEP patients. These trends, however, did not rise to statistical significance within our small population sample. Age, insurance type, and LEP were associated with significant difference in all-cause mortality, however only age and insurance remained significant in adjusted analysis. Conclusion: Our results indicate a non-statistically significant trend towards less variation of surgical treatment variation for early stage breast cancer in the LEP population, including a greater frequency of lumpectomy and less utilization of CPM. Larger, multicenter studies would be needed to affirm and further investigate these trends

Negative Ion Production Rates In Rare Gas-Halide Lasers

This paper reports on dissociative electron attachment in F2, NF3, Cl2, and I2. The principle of the method is to produce a short burst of photoelectrons from a photocathode by means of light from an argon-fluoride laser. Subsequently, by studying the motion of electrons and negative ions in a constant electric field (E) region, information is obtained about drift velocities and effective attachment cross sections. Helium, argon, and nitrogen were used as buffer gases. Of particular interest is a very strong temperature dependence of the attachment coefficient in I2. Measurements were taken from 35 to 110°C, covering an E/N range of 1-50 Townsend. An explanation based on vibrational excitation is presented. Copyright © 1979 by The Institute of Electrical and Electronics Engineers, Inc

Temperature Dependence Of The Electron Attachment Coefficient In Iodine

The attachment coefficient for iodine in a (1% I2+99% N 2) mixture, 50 Torr total pressure, has been measured in an electron swarm experiment from 1 to 50 Townsends (1 Townsend=1Td=10-17 V cm2). As the temperature was increased from 35 to 110°C, the attachment coefficient increased for any E/N (electric field intensity/gas number density) values greater than 7 Td. These results are compared to other experimental data and an explanation for the temperature dependence, based on the population of upper vibrational states, is presented. © 1979 American Institute of Physics

Electron Attachment In Dilute Fluorine-helium Mixtures

We have made an absolute determination of the electron attachment coefficient η (cm-1) in helium containing 0.1-1% fluorine covering an E/N range from 3Td-17Td. At an estimated average energy of 5 eV we find a rate coefficient equal to (7.5±1.5) x10-10 cm3/sec