201 research outputs found

    Part of the D - dimensional Spiked harmonic oscillator spectra

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    The pseudoperturbative shifted - l expansion technique PSLET [5,20] is generalized for states with arbitrary number of nodal zeros. Interdimensional degeneracies, emerging from the isomorphism between angular momentum and dimensionality of the central force Schrodinger equation, are used to construct part of the D - dimensional spiked harmonic oscillator bound - states. PSLET results are found to compare excellenly with those from direct numerical integration and generalized variational methods [1,2].Comment: Latex file, 20 pages, to appear in J. Phys. A: Math. & Ge

    Dirac eigenvalues for a softcore Coulomb potential in d dimensions

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    A single fermion is bound by a softcore central Coulomb potential V(r) = -v/(r^q + b^q)^(1/q), v>0, b>0, q \ge 1, in d>1 spatial dimensions. Envelope theory is used to construct analytic lower bounds for the discrete Dirac energy spectrum. The results are compared to accurate eigenvalues obtained numerically.Comment: 8 pages 1 figur

    Bound - states for truncated Coulomb potentials

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    The pseudoperturbative shifted - ll expansion technique PSLET is generalized for states with arbitrary number of nodal zeros. Bound- states energy eigenvalues for two truncated coulombic potentials are calculated using PSLET. In contrast with shifted large-N expansion technique, PSLET results compare excellently with those from direct numerical integration.Comment: TEX file, 22 pages. To appear in J. Phys. A: Math. & Ge

    Asymptotic solvability of an imaginary cubic oscillator with spikes

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    For the PT symmetric potential of Dorey, Dunning and Tateo we show that in the large angular momentum (i.e., strongly spiked) limit the low-lying eigenstates of this popular non-Hermitian problem coincide with the shifted Hermitian harmonic oscillators calculated at the zero angular momentum. This type of an approximate Hermitization is valid in all the domain where the spectrum of energies remains real. It proves very efficient numerically. The construction is asymmetric with respect to the sign of the subdominant square-root spike, and exhibits a discontinuity at the point where the PT symmetric regularization vanishes.Comment: 20 pages and 2 figure

    Study of a class of non-polynomial oscillator potentials

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    We develop a variational method to obtain accurate bounds for the eigenenergies of H = -Delta + V in arbitrary dimensions N>1, where V(r) is the nonpolynomial oscillator potential V(r) = r^2 + lambda r^2/(1+gr^2), lambda in (-infinity,\infinity), g>0. The variational bounds are compared with results previously obtained in the literature. An infinite set of exact solutions is also obtained and used as a source of comparison eigenvalues.Comment: 16 page

    Temperatures of Exploding Nuclei

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    Breakup temperatures in central collisions of 197Au + 197Au at bombarding energies E/A = 50 to 200 MeV were determined with two methods. Isotope temperatures, deduced from double ratios of hydrogen, helium, and lithium isotopic yields, increase monotonically with bombarding energy from 5 MeV to 12 MeV, in qualitative agreement with a scenario of chemical freeze-out after adiabatic expansion. Excited-state temperatures, derived from yield ratios of states in 4He, 5Li, 6Li, and 8Be, are about 5 MeV, independent of the projectile energy, and seem to reflect the internal temperature of fragments at their final separation from the system. PACS numbers: 25.70.Mn, 25.70.Pq, 25.75.-qComment: 10 pages, RevTeX with 4 included figures; Also available from http://www-kp3.gsi.de/www/kp3/aladin_publications.htm

    Lessons learned from COVID-19 Lockdown: An ASPED/MENA Study on Lifestyle Changes and Quality of Life during Ramadan Fasting in Children and Adolescents living with Type 1 Diabetes

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    Background: Lockdown was a unique experience that affected many aspects of life, particularly during the challenge of Ramadan fasting (RF). Studying this can increase understanding of the effects of lifestyle changes on quality of life (QoL) for children with type 1 diabetes (T1D) during RF. Methods: A cross-sectional study that assessed the effect of lockdown on lifestyle and QoL on fasting children living with T1D during Ramadan in the Middle East and North Africa region (2020-2021). We compared the child (self) and parent (proxy) reports using PEDQoL v3.0 disease specific questionnaire during lockdown and non-lockdown periods, and assessed correlations with lifestyle changes using regression and gap analyses. Results: A total of 998 reports from 499 children with T1D aged 8-18 years (study=276, control=223), and their parents during RF in lockdown and non-lockdown periods. Fathers were more involved in their children’s care during lockdown (p=0.019). Patients had better compliance with treatment (p= 0.002), a reversed sleep pattern (p= 0.033), increased food intake (p=<0.001) and less exercise (p<0.001). Children and parents perceived better QoL during lockdown (p=<0.001) with no differences between their reports in “Diabetes Symptoms”, “Treatment Adherence” and “Communication” domains. Self and proxy reports were different in all domains during non-lockdown (p-values <0.001- 0.009). In gap analysis, although not statistically significant, the gap was approximated between children’s and parents’ perceptions in all domains during lockdown. Conclusion: COVID-19 lockdown had a positive impact on QoL of children living with T1D during RF, possibly due to lifestyle changes and superior psychosocial family dynamics

    Generalized Isoscaling of Isotopic Distributions

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    Generalized isoscaling relationships are proposed that may permit one to relate the isotopic distributions of systems that may not be at the same temperature. The proposed relationships are applied to multifragmentation excitation functions for central Kr+Nb and Ar+Sc collisions.Comment: 20 pages, 5 figure
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