Pairing-excitation versus intruder states in 68Ni and 90Zr

A discussion on the nature of the 0+ states in 68Ni (Z=28, N=40) is presented and a comparison is made with its valence counterpart 90Zr (Z=40, N=50). Evidence is given for a 0+ proton intruder state at only ~2.2 MeV excitation energy in 68Ni, while the analogous neutron intruder states in 90Zr reside at 4126 keV and 5441 keV. The application of a shell-model description of 0+ intruder states reveals that many pair-scattered neutrons across N=40 have to be involved to explain the low excitation energy of the proton-intruder configuration in 68Ni.Comment: 10 pages, 2 figures, 1 tabl

Effectiveness of Planned Educational Program on the Knowledge and Practice regarding Coronary Angiogram Care among Staff Nurses at a selected hospital in Chennai

A study was conducted to assess the effectiveness of planned educational program on knowledge and practice regarding coronary angiogram care among staff nurses at a selected hospital in Chennai. The objectives of the study were: 1. To assess the pre and post-test level of knowledge and practice of the staff nurses regarding coronary angiogram care. 2. To correlate the post-test knowledge and practice of the staff nurses regarding coronary angiogram care. 3. To assess the effectiveness of planned educational program on knowledge and practice of the staff nurses regarding coronary angiogram care. 4. To associate the mean differed level of knowledge and practice of the staff nurses with their selected demographic variables. Methodology : The research approach was quantitative approach and the research design was pre-experimental one group pre-test and post-test. Sixty samples were selected based on sample selection criteria using non probability purposive sampling technique. The study was conducted in MMM hospital, Chennai. Structured questionnaire was used to assess the knowledge level and an observational check list to assess the practice level of staff nurses on coronary angiogram care. The data was collected in three phases. Findings : The overall pre-test level of knowledge revealed that many 39(65%) needs improvement and 21(35%) had moderately adequate knowledge regarding coronary angiogram care. The overall post-test level of knowledge revealed that majority 59(98.33%) had adequate knowledge and 1(1.67%) had moderately adequate knowledge regarding coronary angiogram care. The overall pre-test level of practice revealed that 30(50%) had fair practice and 30(50%) needed improvement and none of the samples had good practice regarding coronary angiogram care. The overall post-test level of practice revealed that all 60(100%) had good practice regarding coronary angiogram care. The calculated ‘r’ test value r = 0.371 showed a moderate positive correlation between post-test knowledge and practice score which was found to be statistically significant at p<0.01. The findings also revealed that the pre-test mean score of knowledge was 13.0 with S.D of 3.71 whereas in the post test the mean score of knowledge was 26.98 with S.D of 1.89. The calculated paired ’t’ test value t = 28.758 found to be statistically significant at p<0.001. The findings revealed that the pre-test mean score of practice was 22.63 with S.D of 2.01 whereas in the post- test the mean score of practice was 40.75 with S.D 1.51. The calculated paired ‘t’ test value t = 57.933 was found to be statistically significant at p<0.001. The findings revealed that there was statistical significance found between the mean differed level of knowledge and the demographic variable age (χ 2 = 4.286) at (p=0.038)and there was no statistically significant association found with other demographic variables. Conclusion : The study concluded that the planned educational program was effective in improving the knowledge and practice of staff nurses. It helps them to be more confident in their duty and to omit errors

Neutron-skin thickness of 208^{208}Pb, and symmetry-energy constraints from the study of the anti-analog giant dipole resonance

The $^{208}$Pb($p$,$n\gamma\bar p$) $^{207}$Pb reaction at a beam energy of 30 MeV has been used to excite the anti-analog of the giant dipole resonance (AGDR) and to measure its $\gamma$-decay to the isobaric analog state in coincidence with proton decay of IAS. The energy of the transition has also been calculated with the self-consistent relativistic random-phase approximation (RRPA), and found to be linearly correlated to the predicted value of the neutron-skin thickness ($\Delta R_{pn}$). By comparing the theoretical results with the measured transition energy, the value of 0.190 $\pm$ 0.028 fm has been determined for $\Delta R_{pn}$ of $^{208}$Pb, in agreement with previous experimental results. The AGDR excitation energy has also been used to calculate the symmetry energy at saturation ($J=32.7 \pm 0.6$ MeV) and the slope of the symmetry energy ($L=49.7 \pm 4.4$ MeV), resulting in more stringent constraints than most of the previous studies.Comment: 6 pages, 5 figures. arXiv admin note: text overlap with arXiv:1205.232

Convexity criteria and uniqueness of absolutely minimizing functions

We show that absolutely minimizing functions relative to a convex Hamiltonian $H:\mathbb{R}^n \to \mathbb{R}$ are uniquely determined by their boundary values under minimal assumptions on $H.$ Along the way, we extend the known equivalences between comparison with cones, convexity criteria, and absolutely minimizing properties, to this generality. These results perfect a long development in the uniqueness/existence theory of the archetypal problem of the calculus of variations in $L^\infty.$Comment: 34 page

Search for Fingerprints of Tetrahedral Symmetry in 156Gd^{156}Gd

Theoretical predictions suggest the presence of tetrahedral symmetry as an explanation for the vanishing intra-band E2-transitions at the bottom of the odd-spin negative parity band in $^{156}Gd$. The present study reports on experiment performed to address this phenomenon. It allowed to determine the intra-band E2 transitions and branching ratios B(E2)/B(E1) of two of the negative-parity bands in $^{156}Gd$.Comment: presented by Q.T. Doan at XLII Zakopane School of Physics: Breaking Frontiers: Submicron Structures in Physics and Biology, May 2008. 5 pages, minor corrections. To be published in the proceeding

First observation of excited states in 173Hg

The neutron-deficient nucleus 173Hg has been studied following fusion-evaporation reactions. The observation of gamma rays decaying from excited states are reported for the first time and a tentative level scheme is proposed. The proposed level scheme is discussed within the context of the systematics of neighbouring neutron-deficient Hg nuclei. In addition to the gamma-ray spectroscopy, the alpha decay of this nucleus has been measured yielding superior precision to earlier measurements.Comment: 5 pages, 4 figure

Intruder bands and configuration mixing in the lead isotopes

A three-configuration mixing calculation is performed in the context of the interacting boson model with the aim to describe recently observed collective bands built on low-lying $0^+$ states in neutron-deficient lead isotopes. The configurations that are included correspond to the regular, spherical states as well as two-particle two-hole and four-particle four-hole excitations across the Z=82 shell gap.Comment: 20 pages, 4 figures, accepted by PRC, reference added for section 1 in this revised versio