Compton Scattering and Photo-absorption Sum Rules on Nuclei

We revisit the photo-absorption sum rule for real Compton scattering from the proton and from nuclear targets. In analogy with the Thomas-Reiche-Kuhn sum rule appropriate at low energies, we propose a new "constituent quark model" sum rule that relates the integrated strength of hadronic resonances to the scattering amplitude on constituent quarks. We study the constituent quark model sum rule for several nuclear targets. In addition we extract the $\alpha=0$ pole contribution for both proton and nuclei. Using the modern high energy proton data we find that the $\alpha=0$ pole contribution differs significantly from the Thomson term, in contrast with the original findings by Damashek and Gilman.Comment: 8 pages, 4 figures, 2 tables; typos corrected; submitted to PR

Isovector Giant Dipole Resonance from the 3D Time-Dependent Density Functional Theory for Superfluid Nuclei

A fully symmetry unrestricted Time-Dependent Density Functional Theory extended to include pairing correlations is used to calculate properties of the isovector giant dipole resonances of the deformed open-shell nuclei 172Yb (axially deformed), 188Os (triaxially deformed), and 238U (axially deformed), and to demonstrate good agreement with experimental data on nuclear photo-absorption cross-sections for two different Skyrme force parametrizations of the energy density functional: SkP and SLy4.Comment: 5 pages, 3 figures, published versio

A Novel Exercise Initiative for Seniors to Improve Balance and Physical Function.

OBJECTIVE: To investigate the feasibility, effectiveness, and short-term effects of an exercise intervention using a novel exercise park in improving seniors' balance, physical function, and quality of life. METHOD: Randomized controlled trial with pre- and post-intervention design (baseline and 18-week intervention) was used. Outcome measures included measures of balance, strength, and function, as well as quality of life and fear of falling. MANCOVA was used to assess differences between groups (control and exercise intervention) over time. RESULTS: Intervention group showed significant improvement on single leg stance (p = .02, 95% confidence interval [CI] = [-8.35, -0.549]), knee strength (p < .01, 95% CI = [-29.14, -5.86]), 2-min walk (p = 0.02, 95% CI = [-19.13, -0.859]), and timed sit to stand (p = .03, 95% CI = [-2.26, -0.143]) tests. DISCUSSION: The exercise park program improved physical function and had high adherence and participation rate. Such intervention has been shown to be safe and therefore might enhance participation in exercise programs for older adults

What doesn’t kill you makes you fitter: A systematic review of high-intensity interval exercise for patients with cardiovascular and metabolic diseases

High-intensity interval exercise (HIIE) has gained popularity in recent years for patients with cardiovascular and metabolic diseases. Despite potential benefits, concerns remain about the safety of the acute response (during and/or within 24 hours postexercise) to a single session of HIIE for these cohorts. Therefore, the aim of this study was to perform a systematic review to evaluate the safety of acute HIIE for people with cardiometabolic diseases. Electronic databases were searched for studies published prior to January 2015, which reported the acute responses of patients with cardiometabolic diseases to HIIE (≥80% peak power output or ≥85% peak aerobic power, VO2peak). Eleven studies met the inclusion criteria (n = 156; clinically stable, aged 27–66 years), with 13 adverse responses reported (~8% of individuals). The rate of adverse responses is somewhat higher compared to the previously reported risk during moderate-intensity exercise. Caution must be taken when prescribing HIIE to patients with cardiometabolic disease. Patients who wish to perform HIIE should be clinically stable, have had recent exposure to at least regular moderate-intensity exercise, and have appropriate supervision and monitoring during and after the exercise session

Deuteron tensor polarization component T_20(Q^2) as a crucial test for deuteron wave functions

The deuteron tensor polarization component T_20(Q^2) is calculated by relativistic Hamiltonian dynamics approach. It is shown that in the range of momentum transfers available in to-day experiments, relativistic effects, meson exchange currents and the choice of nucleon electromagnetic form factors almost do not influence the value of T_20(Q^2). At the same time, this value depends strongly on the actual form of the deuteron wave function, that is on the model of NN-interaction in deuteron. So the existing data for T_20(Q^2) provide a crucial test for deuteron wave functions.Comment: 11 pages, 3 figure

Ultra-low energy scattering of a He atom off a He dimer

We present a new, mathematically rigorous, method suitable for bound state and scattering processes calculations for various three atomic or molecular systems where the underlying forces are of a hard-core nature. We employed this method to calculate the binding energies and the ultra-low energy scattering phase shifts below as well as above the break-up threshold for the three He-atom system. The method is proved to be highly successful and suitable for solving the three-body bound state and scattering problem in configuration space and thus it paves the way to study various three-atomic systems, and to calculate important quantities such as the cross-sections, recombination rates etc.Comment: LaTeX, RevTeX and amssymb styles, 7 pages (25 Kb), 3 table

Deuteron distribution in nuclei and the Levinger's factor

We compute the distribution of quasideuterons in doubly closed shell nuclei. The ground states of $^{16}$O and $^{40}$Ca are described in $ls$ coupling using a realistic hamiltonian including the Argonne $v_{8}^\prime$ and the Urbana IX models of two-- and three--nucleon potentials, respectively. The nuclear wave function contains central and tensor correlations, and correlated basis functions theory is used to evaluate the distribution of neutron-proton pairs, having the deuteron quantum numbers, as a function of their total momentum. By computing the number of deuteron--like pairs we are able to extract the Levinger's factor and compare to both the available experimental data and the predictions of the local density approximation, based on nuclear matter estimates. The agreement with the experiments is excellent, whereas the local density approximation is shown to sizably overestimate the Levinger's factor in the region of the medium nuclei.Comment: 26 pages, 8 figures, typeset using REVTe

Meson-induced correlations of nucleons in nuclear Compton scattering

The non-resonant (seagull) contribution to the nuclear Compton amplitude at low energies is strongly influenced by nucleon correlations arising from meson exchange. We study this problem in a modified Fermi gas model, where nuclear correlation functions are obtained with the help of perturbation theory. The dependence of the mesonic seagull amplitude on the nuclear radius is investigated and the influence of a realistic nuclear density on this amplitude is dicussed. We found that different form factors appear for the static part (proportional to the enhancement constant $\kappa$) of the mesonic seagull amplitude and for the parts, which contain the contribution from electromagnetic polarizabilities.Comment: 15 pages, Latex, epsf.sty, 9 eps figures