scholarly journals In-gap bound states induced by a single nonmagnetic impurity in sign-preserving s -wave superconductors with incipient bands

2017 ◽  
Vol 96 (22) ◽  
Author(s):  
Yi Gao ◽  
Yan Yu ◽  
Tao Zhou ◽  
Huaixiang Huang ◽  
Qiang-Hua Wang
Keyword(s):  
Bound States ◽  
S Wave ◽  
Nonmagnetic Impurity

scholarly journals AMADEUS Experiment: Studies on Antikaon Interactions with Nucleons and Nuclei

2018 ◽  
Vol 46 ◽  
pp. 1860071
Author(s):  
J. Marton ◽  
K. Piscicchia
Keyword(s):  
Bound States ◽  
Experimental Studies ◽  
Drift Chamber ◽  
Kaonic Hydrogen ◽  
Nucleon Interaction ◽  
S Wave ◽  
Data Set ◽  
Electron Positron ◽  
Low Energies ◽  
Kloe Collaboration

The understanding of the low-energy strong interaction involving strangeness is a challenging topic due to resonances and predicted kaonic nuclear bound states. The K- nucleon interaction is strongly attractive at low energies verified in kaonic hydrogen studied in the SIDDHARTA experiment at the DA[Formula: see text]NE electron-positron collider of LNF-INFN (Frascati/Italy). Hyperon resonances like the elusive [Formula: see text] in the s-wave impose questions about its nature. According to theoretical studies it can be described as a dynamically generated resonance with two poles or a quasi-bound [Formula: see text]N state, which could lead to kaonic nuclear bound states (e.g. K-pp). An insight in many open facets of the antikaon interactions can be provided by the AMADEUS experiment at DA[Formula: see text]NE based on the analysis of the data collected in 2004/2005 by the KLOE collaboration, and of the dedicated data set collected in 2012 by AMADEUS in collaboration with KLOE. As a first step data from antikaon-induced reactions in the drift chamber of KLOE were analyzed and yielded new results on antikaon absorption on nuclei. Recent results of the experimental studies and an outlook to the future possibilities within AMADEUS are presented.

scholarly journals Variational calculations for the hydrogen-antihydrogen system with a mass-scaled Born-Oppenheimer potential

Open Physics ◽  
2012 ◽  
Vol 10 (5) ◽  
Author(s):  
Henrik Stegeby ◽  
Konrad Piszczatowski ◽  
Hans Karlsson ◽  
Roland Lindh ◽  
Piotr Froelich
Keyword(s):  
Bound States ◽  
Vibrational Energy ◽  
Scattering Length ◽  
Energy Levels ◽  
Nuclear Interaction ◽  
S Wave ◽  
Proton Antiproton ◽  
Mass Scaling ◽  
Variational Calculations ◽  
Vibrational Energy Levels

AbstractThe problem of proton-antiproton motion in the H-$\bar H$ system is investigated by means of the variational method. We introduce a modified nuclear interaction through mass-scaling of the Born-Oppenheimer potential. This improved treatment of the interaction includes the nondivergent part of the otherwise divergent adiabatic correction and shows the correct threshold behaviour. Using this potential we calculate the vibrational energy levels with angular momentum 0 and 1 and the corresponding nuclear wave functions, as well as the S-wave scattering length. We obtain a full set of all bound states together with a large number of discretized continuum states that might be utilized in variational four-body calculations. The results of our calculations gives an indication of resonance states in the hydrogen-antihydrogen system.

scholarly journals ELECTRONIC BOUND STATES IN PARITY-PRESERVING QED3 APPLIED TO HIGH-Tc CUPRATE SUPERCONDUCTORS

2003 ◽  
Vol 18 (05) ◽  
pp. 725-741 ◽  
Author(s):  
H. R. CHRISTIANSEN ◽  
O. M. DEL CIMA ◽  
M. M. FERREIRA ◽  
J. A. HELAYËL-NETO
Keyword(s):  
Bound States ◽  
Cuprate Superconductors ◽  
Energy Scale ◽  
Spontaneous Breaking ◽  
Electron Interaction ◽  
Oxide Superconductors ◽  
S Wave ◽  
High Tc ◽  
Pair Condensation ◽  
Copper Oxide Superconductors

We consider a parity-preserving QED 3 model with spontaneous breaking of the gauge symmetry as a framework for the evaluation of the electron–electron interaction potential underlying high-T c superconductivity. The fact that the resulting potential, -CsK0(Mr), is non-confining and "weak" (in the sense of Kato) strongly suggests the mechanism of pair-condensation. This potential, compatible with an s-wave order parameter, is then applied to the Schrödinger equation for the sake of numerical calculations, thereby enforcing the existence of bound states. The results worked out by means of our theoretical framework are checked by considering a number of phenomenological data extracted from different copper oxide superconductors. The agreement may motivate a deeper analysis of our model viewing an application to quasiplanar cuprate superconductors. The data analyzed here suggest an energy scale of 1–10 meV for the breaking of the U(1)-symmetry.

scholarly journals Phase Separation and Pairing Fluctuations in Oxide Materials

2020 ◽  
Vol 5 (4) ◽  
pp. 65
Author(s):  
Andreas Bill ◽  
Vladimir Hizhnyakov ◽  
Reinhard K. Kremer ◽  
Götz Seibold ◽  
Aleksander Shelkan ◽  
...  
Keyword(s):  
Phase Separation ◽  
Bound States ◽  
Strong Coupling Expansion ◽  
Low Energy ◽  
S Wave ◽  
Microscopic Mechanism ◽  
Strong Electron ◽  
Particle Spectra ◽  
Pairing Fluctuations ◽  
D Wave

The microscopic mechanism of charge instabilities and the formation of inhomogeneous states in systems with strong electron correlations is investigated. We demonstrate that within a strong coupling expansion the single-band Hubbard model shows an instability towards phase separation and extend the approach also for an analysis of phase separation in the Hubbard-Kanamori hamiltonian as a prototypical multiband model. We study the pairing fluctuations on top of an inhomogeneous stripe state where superconducting correlations in the extended s-wave and d-wave channels correspond to (anti)bound states in the two-particle spectra. Whereas extended s-wave fluctuations are relevant on the scale of the local interaction parameter U, we find that d-wave fluctuations are pronounced in the energy range of the active subband which crosses the Fermi level. As a result, low energy spin and charge fluctuations can transfer the d-wave correlations from the bound states to the low energy quasiparticle bands. Our investigations therefore help to understand the coexistence of stripe correlations and d-wave superconductivity in cuprates.

SUPERSYMMETRIC QUANTUM MECHANICS APPLIED TO NONRELATIVISTIC QUARK MODELS

1993 ◽  
Vol 08 (08) ◽  
pp. 1437-1455 ◽  
Author(s):  
E.J.O. GAVIN ◽  
H. FIEDELDEY ◽  
H. LEEB ◽  
S.A. SOFIANOS
Keyword(s):  
Quantum Mechanics ◽  
Bound States ◽  
Approximation Scheme ◽  
Energy Levels ◽  
Supersymmetric Quantum Mechanics ◽  
S Wave ◽  
Nucleon Spectrum ◽  
Quark Potential ◽  
Quark Models ◽  
Original Potential

We examine the effect of changing the energy levels and normalization constants of bound states corresponding to baryons and mesons in nonrelativistic quark models. We do this by applying the transformations of supersymmetric quantum mechanics (SUSYQM) to the potentials used in these models. In particular, we fit the spectra and leptonic decay widths of [Formula: see text] and [Formula: see text] mesons by modifying several existing [Formula: see text] potentials by means of supersymmetric transformations. It is found that the potentials are unchanged beyond 2 fm, and that fitting the widths induces greater oscillations in the potentials than those generated by adjusting the energy levels only. Transformations of SUSYQM are applied to the hypercentral potential in order to accommodate the Roper resonance in the s-wave nucleon spectrum. The quark-quark potential found by inverting the transformed hypercentral potential via a new exact Abel transform differs significantly from the original potential up to 5 fm from the origin and violates the concavity requirement. The [Formula: see text] potential related to this potential by Lipkin’s rule does not reproduce the meson spectrum. As the Hall-Post lower bound is also accurate for baryons, the results of the application of supersymmetric transformations in this approximation scheme are also considered and compared to the upper bound of the hypercentral approximation.

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