Collective Excitations of (154)Sm nucleus at FEL{gamma}+LHC Collider

The production of collective excitations of the (154)Sm at FEL{gamma}+LHC collider is investigated. We show that this machine will be a powerful tool for investigation of high energy level excitations.Comment: 6 pages, 1 figure, 4 table

Competing electric and magnetic excitations in backward electron scattering from heavy deformed nuclei

Important $E2$ contributions to the $(e,e^{\prime})$ cross sections of low-lying orbital $M1$ excitations are found in heavy deformed nuclei, arising from the small energy separation between the two excitations with $I^{\pi}K = 2^+1$ and 1$^+1$, respectively. They are studied microscopically in QRPA using DWBA. The accompanying $E2$ response is negligible at small momentum transfer $q$ but contributes substantially to the cross sections measured at $\theta = 165 ^{\circ}$ for $0.6 < q_{\rm eff} < 0.9$ fm$^{-1}$ ($40 \le E_i \le 70$ MeV) and leads to a very good agreement with experiment. The electric response is of longitudinal $C2$ type for $\theta \le 175 ^{\circ}$ but becomes almost purely transverse $E2$ for larger backward angles. The transverse $E2$ response remains comparable with the $M1$ response for $q_{\rm eff} > 1.2$ fm$^{-1}$ ($E_i > 100$ MeV) and even dominant for $E_i > 200$ MeV. This happens even at large backward angles $\theta > 175 ^{\circ}$, where the $M1$ dominance is limited to the lower $q$ region.Comment: RevTeX, 19 pages, 8 figures included Accepted for publication in Phys Rev

Medical education reform in Tajikistan: comparison of the conventional one-year family medicine residency program and the new two-year residency program for postgraduate medical education

INTRODUCTION: The last two decades have seen a shift in former Soviet countries from highly specialized to more family medicine-focused systems. Medical education has slowly adjusted to these reforms, although the region is still at risk to have a chronic shortage of family doctors. This paper presents the evaluation of a new post-graduate family medicine program in Tajikistan, focused on competency-based training. The findings are relevant for policy makers, international organizations and practitioners participating in similar medical education reform programs. METHODS: We employed a quasi-experimental control group design and compared intervention residents, control group residents with traditional training, and 1st year residents with no training in two outcomes, clinical knowledge and competencies. We employed two objective measures, a written multiple-choice question test (MCQT) and an Objective Structured Clinical Examination (OSCE), respectively. We report reliability and validity of the measures along with ANOVA, planned contrasts and effect size estimates to examine differences across groups. RESULTS: We found statistically significant differences in both clinical knowledge and competencies between intervention and control groups. We also detected a large intervention effect size. Participants in the intervention outperformed control group participants in the two measures. Our analysis suggests that intervention and control group participants are comparable in terms of initial knowledge and competencies, strengthening the argument that the intervention caused the improvement in the program outcomes. DISCUSSION: Receiving tailored training and structured opportunities to practice knowledge and competencies in clinical settings have a positive effect on the education of family medicine doctors in Tajikistan. Our results support curriculum reform and investment in medical education in the form of longer and supervised on-the-job preparation designed to be more in line with international standards. We discuss suggestions for future studies and potential requirements to inform replicability in other countries. CONCLUSION: Family medicine is well recognized as central to health systems throughout the world, but high quality residency training lags behind in some countries. Our study showed that investing in family medicine residency programs and structured training is effective in increasing critical clinical competencies. We encourage promoting comprehensive post graduate family medicine doctor training so that the goals of a family medicine centered health system are attainable

Orbital Magnetic Dipole Mode in Deformed Clusters: A Fully Microscopic Analysis

The orbital M1 collective mode predicted for deformed clusters in a schematic model is studied in a self-consistent random-phase-approximation approach which fully exploits the shell structure of the clusters. The microscopic mechanism of the excitation is clarified and the close correlation with E2 mode established. The study shows that the M1 strength of the mode is fragmented over a large energy interval. In spite of that, the fraction remaining at low energy, well below the overwhelming dipole plasmon resonance, is comparable to the strength predicted in the schematic model. The importance of this result in view of future experiments is stressed.Comment: 10 pages, 3 Postscript figures, uses revte

Universality of Symmetry and Mixed-symmetry Collective Nuclear States

The global correlation in the observed variation with mass number of the $E2$ and summed $M1$ transition strengths is examined for rare earth nuclei. It is shown that a theory of correlated $S$ and $D$ fermion pairs with a simple pairing plus quadrupole interaction leads naturally to this universality. Thus a unified and quantitative description emerges for low-lying quadrupole and dipole strengths.Comment: In press, Phys. Rev. Lett. 199

Temperature Dependence of Damping and Frequency Shifts of the Scissors Mode of a trapped Bose-Einstein Condensate

We have studied the properties of the scissors mode of a trapped Bose-Einstein condensate of $^{87}$Rb atoms at finite temperature. We measured a significant shift in the frequency of the mode below the hydrodynamic limit and a strong dependence of the damping rate as the temperature increased. We compared our damping rate results to recent theoretical calculations for other observed collective modes finding a fair agreement. From the frequency measurements we deduce the moment of inertia of the gas and show that it is quenched below the transition point, because of the superfluid nature of the condensed gas.Comment: 5 pages, 4 figure

Scissors modes in triaxial metal clusters

We study the scissors mode (orbital M1 excitations) in small Na clusters, triaxial metal clusters ${\rm Na}_{12}$ and ${\rm Na}_{16}$ and the close-to-spherical ${{\rm Na}_9}^+$, all described in DFT with detailed ionic background. The scissors modes built on spin-saturated ground and spin-polarized isomeric states are analyzed in virtue of both macroscopic collective and microscopic shell-model treatments. It is shown that the mutual destruction of Coulomb and the exchange-correlation parts of the residual interaction makes the collective shift small and the net effect can depend on details of the actual excited state. The crosstalk with dipole and spin-dipole modes is studied in detail. In particular, a strong crosstalk with spin-dipole negative-parity mode is found in the case of spin-polarized states. Triaxiality and ionic structure considerably complicate the scissors response, mainly at expense of stronger fragmentation of the strength. Nevertheless, even in these complicated cases the scissors mode is mainly determined by the global deformation. The detailed ionic structure destroys the spherical symmetry and can cause finite M1 response (transverse optical mode) even in clusters with zero global deformation. But its strength turns out to be much smaller than for the genuine scissors modes in deformed systems.Comment: 17 pages, 5 figure

Magnetic Dipole Sum Rules for Odd-Mass Nuclei

Sum rules for the total- and scissors-mode M1 strength in odd-A nuclei are derived within the single-j interacting boson-fermion model. We discuss the physical content and geometric interpretation of these sum rules and apply them to ^{167}Er and ^{161}Dy. We find consistency with the former measurements but not with the latter.Comment: 13 pages, Revtex, 1 figure, Phys. Rev. Lett. in pres

Level densities and γ\gamma-strength functions in 148,149^{148,149}Sm

The level densities and $\gamma$-strength functions of the weakly deformed $^{148}$Sm and $^{149}$Sm nuclei have been extracted. The temperature versus excitation energy curve, derived within the framework of the micro canonical ensemble, shows structures, which we associate with the break up of Cooper pairs. The nuclear heat capacity is deduced within the framework of both the micro canonical and the canonical ensemble. We observe negative heat capacity in the micro canonical ensemble whereas the canonical heat capacity exhibits an S-shape as function of temperature, both signals of a phase transition. The structures in the $\gamma$-strength functions are discussed in terms of the pygmy resonance and the scissors mode built on exited states. The samarium results are compared with data for the well deformed $^{161,162}$Dy, $^{166,167}$Er and $^{171,172}$Yb isotopes and with data from (n,$\gamma$)-experiments and giant dipole resonance studies.Comment: 12 figure