Level structures in 180Hf from the β decay of 180Lu

1992 ◽  
Vol 70 (6) ◽  
pp. 395-400 ◽  
Author(s):  
P. C. Sood ◽  
R. K. Sheline ◽  
R. W. Hoff
Keyword(s):  
Ground State ◽  
Transfer Reaction ◽  
Experimental Investigations ◽  
Transition Rates ◽  
Β Decay ◽  
Excitation Energies ◽  
Quasiparticle Excitation ◽  
Decay Modes ◽  
Corroborative Evidence ◽  
Neutron Configuration

Configuration assignments to the levels of 180Hf populated in the β decay of the 5.7 min ground state of 180Lu are derived based on the observed β-transition rates, calculated two-quasiparticle excitation energies, and the observed decay modes of the levels under consideration. Corroborative evidence is sought from the results of the other experimental investigations including (n, γ), (n, 2γ), (n, n′γ), and particle transfer reaction studies. Specifically the 1607.7 and 1742.7 keV levels are assigned the IπK = 4+4 and 5+4 {7/2[514] + 1/2[510]} two-neutron configuration, and the 1374.7 and 1609.7 keV levels are assigned the 4−4 and 5−5 {9/2[624] + 1/2[510]} two-neutron configuration.

scholarly journals Observation of chiral surface excitons in a topological insulator Bi2Se3

2019 ◽  
Vol 116 (10) ◽  
pp. 4006-4011 ◽  
Author(s):  
H.-H. Kung ◽  
A. P. Goyal ◽  
D. L. Maslov ◽  
X. Wang ◽  
A. Lee ◽  
...  
Keyword(s):  
Polarized Light ◽  
Orbit Coupling ◽  
Experimental Investigations ◽  
Composite Particles ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Excitation Energies ◽  
Circularly Polarized Light ◽  
Pl Emission ◽  
Strong Spin

The protected electron states at the boundaries or on the surfaces of topological insulators (TIs) have been the subject of intense theoretical and experimental investigations. Such states are enforced by very strong spin–orbit interaction in solids composed of heavy elements. Here, we study the composite particles—chiral excitons—formed by the Coulomb attraction between electrons and holes residing on the surface of an archetypical 3D TI,Bi2Se3. Photoluminescence (PL) emission arising due to recombination of excitons in conventional semiconductors is usually unpolarized because of scattering by phonons and other degrees of freedom during exciton thermalization. On the contrary, we observe almost perfectly polarization-preserving PL emission from chiral excitons. We demonstrate that the chiral excitons can be optically oriented with circularly polarized light in a broad range of excitation energies, even when the latter deviate from the (apparent) optical band gap by hundreds of millielectronvolts, and that the orientation remains preserved even at room temperature. Based on the dependences of the PL spectra on the energy and polarization of incident photons, we propose that chiral excitons are made from massive holes and massless (Dirac) electrons, both with chiral spin textures enforced by strong spin–orbit coupling. A theoretical model based on this proposal describes quantitatively the experimental observations. The optical orientation of composite particles, the chiral excitons, emerges as a general result of strong spin–orbit coupling in a 2D electron system. Our findings can potentially expand applications of TIs in photonics and optoelectronics.

scholarly journals A Class of Non-Kekulé Molecules with Low Excitation Energies

2007 ◽  
Vol 62 (11) ◽  
pp. 1433-1436
Author(s):  
Fritz Dietz ◽  
Nedko Drebov ◽  
Nikolai Tyutyulkov
Keyword(s):  
Molecular Orbital ◽  
Ground State ◽  
Excitation Energies ◽  
Triplet Ground State ◽  
Molecular Systems ◽  
Structural Principle

A class of non-Kekulé molecular systems with a new structural principle and low excitation energies or with a triplet ground state was investigated theoretically. The systems consist of a non-Kekulé monoradical, possessing a non-bonding molecular orbital linked in a specific way to another monoradical.

scholarly journals Complex ground-state and excitation energies in coupled-cluster theory

2021 ◽  
pp. e1968056
Author(s):  
Simon Thomas ◽  
Florian Hampe ◽  
Stella Stopkowicz ◽  
Jürgen Gauss
Keyword(s):  
Ground State ◽  
Coupled Cluster ◽  
Excitation Energies ◽  
Coupled Cluster Theory ◽  
Cluster Theory

scholarly journals Impact of uncertainties of unbound 10Li on the ground state of two-neutron halo 11Li

2020 ◽  
Author(s):  
Jagit Singh ◽  
Wataru Horiuchi
Keyword(s):  
Ground State ◽  
Halo Nucleus ◽  
Transfer Reaction ◽  
Neutron Halo ◽  
Structure Model ◽  
Continuum States ◽  
Normal Core ◽  
Configuration Mixing ◽  
Three Body ◽  
Neutron Transfer Reaction

Recently, the energy spectrum of \boldsymbol{^{10}}10Li was measured upto \boldsymbol{4.6}4.6 MeV, via one-neutron transfer reaction \boldsymbol{d(^{9}\textrm{Li},~p)^{10}\textrm{Li}}𝐝(9Li,𝐩)10Li. Considering the ambiguities on the \boldsymbol{^{10}}10Li continuum spectrum with reference to new data, we report the configuration mixing in the ground state of the two-neutron halo nucleus \boldsymbol{^{11}}11Li for two different choices of the \boldsymbol{^{9}{\textrm{Li}}+n}9Li+𝐧 potential. For the present study, we employ a three-body (\boldsymbol{\textrm{core}+n+n}core+𝐧+𝐧) structure model developed for describing the two-neutron halo system by explicit coupling of unbound continuum states of the subsystem (\boldsymbol{\textrm{core}+n}core+𝐧), and discuss the two-neutron correlations in the ground state of \boldsymbol{^{11}}11Li.

scholarly journals Structural dynamics of the Ca2+-ATPase studied by time-resolved infrared spectroscopy

2008 ◽  
Vol 22 (2-3) ◽  
pp. 63-82 ◽  
Author(s):  
Andreas Barth
Keyword(s):  
Infrared Spectroscopy ◽  
Structural Dynamics ◽  
Ground State ◽  
Transfer Reaction ◽  
High Reactivity ◽  
Acetyl Phosphate ◽  
Time Resolved ◽  
Closed Conformation ◽  
Sarcoplasmic Reticulum Membrane ◽  
Time Resolved Infrared Spectroscopy

This review discusses the contribution of time-resolved infrared spectroscopy to the understanding of the Ca2+pump in the sarcoplasmic reticulum membrane of skeletal muscle cells (SERCA1a). The focus is on interactions of the substrate ATP with the ATPase and on the bond parameters of the phosphoenzyme phosphate group. Functional groups throughout the ATP molecule are important for stabilising the closed conformation of the ATP–ATPase complex and for fast phosphorylation of the ATPase. Dissociation of the reaction product ADP after phosphorylation leads to a more open average conformation of the enzyme and does not trigger the transition from the first phosphoenzyme Ca2E1P to the second E2P. The P–O bond between phosphate and aspartyl moieties is weaker in Ca2E1P and E2P than in acetyl phosphate in aqueous solution, which explains the high reactivity of the phosphoenzymes. This ground state property of the phosphoenzymes prepares for a phosphate transfer reaction with dissociative character.

scholarly journals Electron-capture modes with realistic nuclear structure calculations

2019 ◽  
Vol 21 ◽  
pp. 4
Author(s):  
P. G. Giannaka ◽  
T. S. Kosmas
Keyword(s):  
Electron Capture ◽  
Cross Sections ◽  
Nuclear Reactions ◽  
Random Phase ◽  
Point Of View ◽  
Electron Neutrino ◽  
Β Decay ◽  
Decay Modes ◽  
Theory Point ◽  
Nuclear Structure Calculations

Nuclear electron capture posses prominent position among other weak interaction processes occuring in explosive nucleosynthesis. In particular, this process plays important role in the core-colapse of massive stars by modifying the electron to baryon ratio Ye. From a nuclear theory point of view, such processes may be studied by using the same nuclear methods (e.g. the quasi-particle random phase approximation, QRPA), employed in the present work with these used for the one-body charge changing nuclear reactions (β-decay modes, charged-current electron-neutrino absorption by nuclei, etc). In this work we calculate e−-capture cross sections on 56Fe using two different approaches. At first, original cross section calculations are perfored by using the pn-QRPA method considering all the accessible transitions of the final nucleus 56Mn. Secondly, we evaluate the Gamow-Teller strength distributions and obtain the cross sections at the limit of zero-momentum transfer. The agreement between the two methods is very good.

scholarly journals Calculations of the decay transitions of the modified Pöschl–Teller potential model via Bohr Hamiltonian technique

2017 ◽  
Vol 26 (11) ◽  
pp. 1750073 ◽  
Author(s):  
Nahid Soheibi ◽  
Majid Hamzavi ◽  
Mahdi Eshghi ◽  
Sameer M. Ikhdair
Keyword(s):  
Experimental Data ◽  
Ground State ◽  
Potential Model ◽  
Electric Quadrupole ◽  
Numerical Results ◽  
Transition Rates ◽  
Collective Hamiltonian

We calculate the eigenvalues and their corresponding eigenfunctions of the Bohr’s collective Hamiltonian with the help of the modified Pöschl–Teller (MPT) potential model within [Formula: see text]-unstable structure. Our numerical results for the ground state (g.s.) [Formula: see text] and [Formula: see text] band heads, together with the electric quadrupole [Formula: see text] transition rates, are displayed and compared with the available experimental data.

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